{ "version": "2.2", "instance": { "san-20260630.htm": { "nsprefix": "san", "nsuri": "http://santander.co.uk/20260630", "dts": { "inline": { "local": [ "san-20260630.htm" ] }, "schema": { "local": [ "san-20260630.xsd" ], "remote": [ "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd", "http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd", "http://www.xbrl.org/2003/xl-2003-12-31.xsd", "http://www.xbrl.org/2003/xlink-2003-12-31.xsd", "http://www.xbrl.org/2005/xbrldt-2005.xsd", "http://www.xbrl.org/2006/ref-2006-02-27.xsd", "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd", "http://www.xbrl.org/lrr/role/net-2009-12-16.xsd", "http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd", "https://www.xbrl.org/2020/extensible-enumerations-2.0.xsd", "https://www.xbrl.org/2023/calculation-1.1.xsd", "https://www.xbrl.org/dtr/type/2020-01-21/types.xsd", "https://www.xbrl.org/dtr/type/2022-03-31/types.xsd", "https://www.xbrl.org/dtr/type/2024-01-31/types.xsd", "https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd", "https://xbrl.fasb.org/srt/2025/elts/srt-roles-2025.xsd", "https://xbrl.fasb.org/srt/2025/elts/srt-types-2025.xsd", "https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/dimensions-ea/rol_ifrs_ea-dim_2025-03-27.xsd", "https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/dimensions/rol_full_ifrs-dim_2025-03-27.xsd", "https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd", "https://xbrl.sec.gov/country/2025/country-2025.xsd", "https://xbrl.sec.gov/dei/2025/dei-2025.xsd" ] }, "calculationLink": { "local": [ "san-20260630_cal.xml" ] }, "definitionLink": { "local": [ "san-20260630_def.xml" ], "remote": [ "https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/dimensions-ea/dim_ifrs_ea_2025-03-27_role-995000.xml", "https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/dimensions/dim_full_ifrs_2025-03-27_role-995000.xml" ] }, "labelLink": { "local": [ "san-20260630_lab.xml" ] }, "presentationLink": { "local": [ "san-20260630_pre.xml" ] } }, "keyStandard": 238, "keyCustom": 169, "axisStandard": 35, "axisCustom": 14, "memberStandard": 56, "memberCustom": 134, "hidden": { "total": 6, "http://xbrl.sec.gov/dei/2025": 6 }, "contextCount": 864, "entityCount": 1, "segmentCount": 207, "elementCount": 819, "unitCount": 11, "baseTaxonomies": { "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full": 1426, "http://xbrl.sec.gov/dei/2025": 8 }, "report": { "R1": { "role": "http://santander.co.uk/role/CoverPage", "longName": "0000001 - Document - Cover Page", "shortName": "Cover Page", "isDefault": "true", "groupType": "document", "subGroupType": "", "menuCat": "Cover", "order": "1", "firstAnchor": { "contextRef": "c-1", "name": "dei:DocumentType", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "span", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "dei:DocumentType", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "span", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R2": { "role": "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "longName": "9952151 - Statement - Condensed Consolidated Income Statement (Unaudited)", "shortName": "Condensed Consolidated Income Statement (Unaudited)", "isDefault": "false", "groupType": "statement", "subGroupType": "", "menuCat": "Statements", "order": "2", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:RevenueFromInterest", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": null }, "R3": { "role": "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited", "longName": "9952152 - Statement - Condensed Consolidated Statement of Comprehensive Income (Unaudited)", "shortName": "Condensed Consolidated Statement of Comprehensive Income (Unaudited)", "isDefault": "false", "groupType": "statement", "subGroupType": "", "menuCat": "Statements", "order": "3", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:ProfitLoss", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R4": { "role": "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "longName": "9952153 - Statement - Condensed Consolidated Balance Sheet (Unaudited)", "shortName": "Condensed Consolidated Balance Sheet (Unaudited)", "isDefault": "false", "groupType": "statement", "subGroupType": "", "menuCat": "Statements", "order": "4", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:CashAndBankBalancesAtCentralBanks", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:OtherFinancialAssetsAtFairValueThroughProfitOrLoss", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R5": { "role": "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited", "longName": "9952154 - Statement - Condensed Consolidated Cash Flow Statement (Unaudited)", "shortName": "Condensed Consolidated Cash Flow Statement (Unaudited)", "isDefault": "false", "groupType": "statement", "subGroupType": "", "menuCat": "Statements", "order": "5", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:ProfitLossBeforeTax", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:AdjustmentsForReconcileProfitLoss", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R6": { "role": "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "longName": "9952155 - Statement - Condensed Consolidated Statement of Changes in Equity (Unaudited)", "shortName": "Condensed Consolidated Statement of Changes in Equity (Unaudited)", "isDefault": "false", "groupType": "statement", "subGroupType": "", "menuCat": "Statements", "order": "6", "firstAnchor": { "contextRef": "c-186", "name": "ifrs-full:Equity", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-186", "name": "ifrs-full:Equity", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R7": { "role": "http://santander.co.uk/role/CreditRisk", "longName": "9952156 - Disclosure - Credit Risk", "shortName": "Credit Risk", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "7", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfCreditRiskExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfCreditRiskExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R8": { "role": "http://santander.co.uk/role/CapitalRisk", "longName": "9952157 - Disclosure - Capital Risk", "shortName": "Capital Risk", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "8", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfCapitalRiskTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfCapitalRiskTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R9": { "role": "http://santander.co.uk/role/MarketRisk", "longName": "9952158 - Disclosure - Market Risk", "shortName": "Market Risk", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "9", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfMarketRiskExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfMarketRiskExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R10": { "role": "http://santander.co.uk/role/ACCOUNTINGPOLICIES", "longName": "9952159 - Disclosure - ACCOUNTING POLICIES", "shortName": "ACCOUNTING POLICIES", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "10", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfMaterialAccountingPolicyInformationExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfMaterialAccountingPolicyInformationExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R11": { "role": "http://santander.co.uk/role/SEGMENTS", "longName": "9952160 - Disclosure - SEGMENTS", "shortName": "SEGMENTS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "11", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfEntitysReportableSegmentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfEntitysReportableSegmentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R12": { "role": "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONS", "longName": "9952161 - Disclosure - OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS", "shortName": "OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "12", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfExpensesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfExpensesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R13": { "role": "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGES", "longName": "9952162 - Disclosure - CREDIT IMPAIRMENT CHARGES", "shortName": "CREDIT IMPAIRMENT CHARGES", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "13", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfImpairmentChargesOnFinancialAssetsExplanatoryTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfImpairmentChargesOnFinancialAssetsExplanatoryTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R14": { "role": "http://santander.co.uk/role/TAXATION", "longName": "9952163 - Disclosure - TAXATION", "shortName": "TAXATION", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "14", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfIncomeTaxExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfIncomeTaxExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R15": { "role": "http://santander.co.uk/role/DIVIDENDSONORDINARYSHARES", "longName": "9952164 - Disclosure - DIVIDENDS ON ORDINARY SHARES", "shortName": "DIVIDENDS ON ORDINARY SHARES", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "15", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDividendsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDividendsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R16": { "role": "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTS", "longName": "9952165 - Disclosure - DERIVATIVE FINANCIAL INSTRUMENTS", "shortName": "DERIVATIVE FINANCIAL INSTRUMENTS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "16", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDerivativeFinancialInstrumentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDerivativeFinancialInstrumentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R17": { "role": "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSS", "longName": "9952166 - Disclosure - OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS", "shortName": "OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "17", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfFinancialInstrumentsAtFairValueThroughProfitOrLossExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfFinancialInstrumentsAtFairValueThroughProfitOrLossExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R18": { "role": "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERS", "longName": "9952167 - Disclosure - LOANS AND ADVANCES TO CUSTOMERS", "shortName": "LOANS AND ADVANCES TO CUSTOMERS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "18", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfLoansAndAdvancesToCustomersExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfLoansAndAdvancesToCustomersExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R19": { "role": "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDS", "longName": "9952168 - Disclosure - SECURITISATIONS AND COVERED BONDS", "shortName": "SECURITISATIONS AND COVERED BONDS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "19", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfSecuritisationsAndCoveredBondsExplanatoryTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfSecuritisationsAndCoveredBondsExplanatoryTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R20": { "role": "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADING", "longName": "9952169 - Disclosure - REVERSE REPURCHASE AGREEMENTS \u2013 NON-TRADING", "shortName": "REVERSE REPURCHASE AGREEMENTS \u2013 NON-TRADING", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "20", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfReverseRepurchaseAgreementsNonTradingTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfReverseRepurchaseAgreementsNonTradingTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R21": { "role": "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOST", "longName": "9952170 - Disclosure - OTHER FINANCIAL ASSETS AT AMORTISED COST", "shortName": "OTHER FINANCIAL ASSETS AT AMORTISED COST", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "21", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherFinancialAssetsAtAmortisedCostTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherFinancialAssetsAtAmortisedCostTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R22": { "role": "http://santander.co.uk/role/INTERESTSINOTHERENTITIES", "longName": "9952171 - Disclosure - INTERESTS IN OTHER ENTITIES", "shortName": "INTERESTS IN OTHER ENTITIES", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "22", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfInterestsInOtherEntitiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfInterestsInOtherEntitiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R23": { "role": "http://santander.co.uk/role/INTANGIBLEASSETS", "longName": "9952172 - Disclosure - INTANGIBLE ASSETS", "shortName": "INTANGIBLE ASSETS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "23", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfIntangibleAssetsAndGoodwillExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfIntangibleAssetsAndGoodwillExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R24": { "role": "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENT", "longName": "9952173 - Disclosure - PROPERTY, PLANT AND EQUIPMENT", "shortName": "PROPERTY, PLANT AND EQUIPMENT", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "24", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfPropertyPlantAndEquipmentExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfPropertyPlantAndEquipmentExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R25": { "role": "http://santander.co.uk/role/DEPOSITSBYBANKS", "longName": "9952174 - Disclosure - DEPOSITS BY BANKS", "shortName": "DEPOSITS BY BANKS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "25", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDepositsFromBanksExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDepositsFromBanksExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R26": { "role": "http://santander.co.uk/role/DEPOSITSBYCUSTOMERS", "longName": "9952175 - Disclosure - DEPOSITS BY CUSTOMERS", "shortName": "DEPOSITS BY CUSTOMERS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "26", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDepositsFromCustomersExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDepositsFromCustomersExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R27": { "role": "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADING", "longName": "9952176 - Disclosure - REPURCHASE AGREEMENTS \u2013 NON-TRADING", "shortName": "REPURCHASE AGREEMENTS \u2013 NON-TRADING", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "27", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfRepurchaseAndReverseRepurchaseAgreementsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": null }, "R28": { "role": "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSS", "longName": "9952177 - Disclosure - OTHER FINANCIAL LIABILITIES AT FAIR VALUE THROUGH PROFIT OR LOSS", "shortName": "OTHER FINANCIAL LIABILITIES AT FAIR VALUE THROUGH PROFIT OR LOSS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "28", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R29": { "role": "http://santander.co.uk/role/DEBTSECURITIESINISSUE", "longName": "9952178 - Disclosure - DEBT SECURITIES IN ISSUE", "shortName": "DEBT SECURITIES IN ISSUE", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "29", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDebtSecuritiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDebtSecuritiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R30": { "role": "http://santander.co.uk/role/PROVISIONS", "longName": "9952179 - Disclosure - PROVISIONS", "shortName": "PROVISIONS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "30", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfProvisionsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfProvisionsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R31": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANS", "longName": "9952180 - Disclosure - RETIREMENT BENEFIT PLANS", "shortName": "RETIREMENT BENEFIT PLANS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "31", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfEmployeeBenefitsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfEmployeeBenefitsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R32": { "role": "http://santander.co.uk/role/SUBORDINATEDLIABILITIES", "longName": "9952181 - Disclosure - SUBORDINATED LIABILITIES", "shortName": "SUBORDINATED LIABILITIES", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "32", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfSubordinatedLiabilitiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfSubordinatedLiabilitiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R33": { "role": "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTS", "longName": "9952182 - Disclosure - CONTINGENT LIABILITIES AND COMMITMENTS", "shortName": "CONTINGENT LIABILITIES AND COMMITMENTS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "33", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R34": { "role": "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTS", "longName": "9952183 - Disclosure - OTHER EQUITY INSTRUMENTS", "shortName": "OTHER EQUITY INSTRUMENTS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "34", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherEquityInstrumentsExplanatoryTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherEquityInstrumentsExplanatoryTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R35": { "role": "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETS", "longName": "9952184 - Disclosure - ASSETS CHARGED AS SECURITY FOR LIABILITIES AND COLLATERAL ACCEPTED AS SECURITY FOR ASSETS", "shortName": "ASSETS CHARGED AS SECURITY FOR LIABILITIES AND COLLATERAL ACCEPTED AS SECURITY FOR ASSETS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "35", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfCollateralExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfCollateralExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R36": { "role": "http://santander.co.uk/role/RELATEDPARTYDISCLOSURES", "longName": "9952185 - Disclosure - RELATED PARTY DISCLOSURES", "shortName": "RELATED PARTY DISCLOSURES", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "36", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfRelatedPartyExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfRelatedPartyExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R37": { "role": "http://santander.co.uk/role/FINANCIALINSTRUMENTS", "longName": "9952186 - Disclosure - FINANCIAL INSTRUMENTS", "shortName": "FINANCIAL INSTRUMENTS", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "37", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfFinancialInstrumentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfFinancialInstrumentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R38": { "role": "http://santander.co.uk/role/ACQUISITIONOFTSB", "longName": "9952187 - Disclosure - ACQUISITION OF TSB", "shortName": "ACQUISITION OF TSB", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "38", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfBusinessCombinationsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfBusinessCombinationsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R39": { "role": "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATE", "longName": "9952188 - Disclosure - EVENTS AFTER THE BALANCE SHEET DATE", "shortName": "EVENTS AFTER THE BALANCE SHEET DATE", "isDefault": "false", "groupType": "disclosure", "subGroupType": "", "menuCat": "Notes", "order": "39", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfEventsAfterReportingPeriodExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfEventsAfterReportingPeriodExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R40": { "role": "http://santander.co.uk/role/ACCOUNTINGPOLICIESPolicies", "longName": "9955511 - Disclosure - ACCOUNTING POLICIES (Policies)", "shortName": "ACCOUNTING POLICIES (Policies)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "policies", "menuCat": "Policies", "order": "40", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfBasisOfPreparationOfFinancialStatementsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfBasisOfPreparationOfFinancialStatementsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R41": { "role": "http://santander.co.uk/role/CreditRiskTables", "longName": "9955512 - Disclosure - Credit Risk (Tables)", "shortName": "Credit Risk (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "41", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfBaseExpectedCreditLossesToProbabilityWeightedEstimatedCreditLossesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfBaseExpectedCreditLossesToProbabilityWeightedEstimatedCreditLossesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R42": { "role": "http://santander.co.uk/role/CapitalRiskTables", "longName": "9955513 - Disclosure - Capital Risk (Tables)", "shortName": "Capital Risk (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "42", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfRegulatoryCapitalResourcesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfRegulatoryCapitalResourcesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R43": { "role": "http://santander.co.uk/role/MarketRiskTables", "longName": "9955514 - Disclosure - Market Risk (Tables)", "shortName": "Market Risk (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "43", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfNIIAndEveSensitivityOfInterestRateRiskTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfNIIAndEveSensitivityOfInterestRateRiskTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R44": { "role": "http://santander.co.uk/role/ACCOUNTINGPOLICIESTables", "longName": "9955515 - Disclosure - ACCOUNTING POLICIES (Tables)", "shortName": "ACCOUNTING POLICIES (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "44", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DescriptionOfVoluntaryChangeInAccountingPolicy", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DescriptionOfVoluntaryChangeInAccountingPolicy", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R45": { "role": "http://santander.co.uk/role/SEGMENTSTables", "longName": "9955516 - Disclosure - SEGMENTS (Tables)", "shortName": "SEGMENTS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "45", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfOperatingSegmentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfOperatingSegmentsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R46": { "role": "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSTables", "longName": "9955517 - Disclosure - OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS (Tables)", "shortName": "OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "46", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOperatingExpensesBeforeCreditImpairmentRestructuringAndSpecificProvisionsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOperatingExpensesBeforeCreditImpairmentRestructuringAndSpecificProvisionsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R47": { "role": "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESANDPROVISIONSTables", "longName": "9955518 - Disclosure - CREDIT IMPAIRMENT CHARGES AND PROVISIONS (Tables)", "shortName": "CREDIT IMPAIRMENT CHARGES AND PROVISIONS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "47", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailedInformationOfImpairmentChargesAndProvisionsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailedInformationOfImpairmentChargesAndProvisionsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R48": { "role": "http://santander.co.uk/role/TAXATIONTables", "longName": "9955519 - Disclosure - TAXATION (Tables)", "shortName": "TAXATION (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "48", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfReconciliationOfChargeResultingFromApplyingUKCorporationTaxRateExplanatoryTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfReconciliationOfChargeResultingFromApplyingUKCorporationTaxRateExplanatoryTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R49": { "role": "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSTables", "longName": "9955520 - Disclosure - DERIVATIVE FINANCIAL INSTRUMENTS (Tables)", "shortName": "DERIVATIVE FINANCIAL INSTRUMENTS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "49", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfNotionalAndFairValueAmountsOfDerivativeFinancialInstrumentsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfNotionalAndFairValueAmountsOfDerivativeFinancialInstrumentsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R50": { "role": "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSTables", "longName": "9955521 - Disclosure - OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS (Tables)", "shortName": "OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "50", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfFinancialInstrumentsDesignatedAtFairValueThroughProfitOrLossExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfFinancialInstrumentsDesignatedAtFairValueThroughProfitOrLossExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R51": { "role": "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSTables", "longName": "9955522 - Disclosure - LOANS AND ADVANCES TO CUSTOMERS (Tables)", "shortName": "LOANS AND ADVANCES TO CUSTOMERS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "51", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfNetLoansAndAdvancesToCustomersTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfNetLoansAndAdvancesToCustomersTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R52": { "role": "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSTables", "longName": "9955523 - Disclosure - SECURITISATIONS AND COVERED BONDS (Tables)", "shortName": "SECURITISATIONS AND COVERED BONDS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "52", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfAnalysisOfSecuritisationsAndCoveredBondsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfAnalysisOfSecuritisationsAndCoveredBondsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R53": { "role": "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGTables", "longName": "9955524 - Disclosure - REVERSE REPURCHASE AGREEMENTS \u2013 NON-TRADING (Tables)", "shortName": "REVERSE REPURCHASE AGREEMENTS \u2013 NON-TRADING (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "53", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfRepurchaseAndReverseRepurchaseAgreementsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": null }, "R54": { "role": "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTTables", "longName": "9955525 - Disclosure - OTHER FINANCIAL ASSETS AT AMORTISED COST (Tables)", "shortName": "OTHER FINANCIAL ASSETS AT AMORTISED COST (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "54", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailedInformationOfOtherFinancialAssetsAtAmortisedCostTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailedInformationOfOtherFinancialAssetsAtAmortisedCostTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R55": { "role": "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTTables", "longName": "9955526 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Tables)", "shortName": "PROPERTY, PLANT AND EQUIPMENT (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "55", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R56": { "role": "http://santander.co.uk/role/DEPOSITSBYBANKSTables", "longName": "9955527 - Disclosure - DEPOSITS BY BANKS (Tables)", "shortName": "DEPOSITS BY BANKS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "56", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDepositsByBankTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDepositsByBankTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R57": { "role": "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSTables", "longName": "9955528 - Disclosure - DEPOSITS BY CUSTOMERS (Tables)", "shortName": "DEPOSITS BY CUSTOMERS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "57", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailedInformationAboutDepositsFromCustomersTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailedInformationAboutDepositsFromCustomersTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R58": { "role": "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGTables", "longName": "9955529 - Disclosure - REPURCHASE AGREEMENTS \u2013 NON-TRADING (Tables)", "shortName": "REPURCHASE AGREEMENTS \u2013 NON-TRADING (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "58", "firstAnchor": { "contextRef": "c-1", "name": "san:DetailedDisclosureOfRepurchaseAgreementsNonTradingTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DetailedDisclosureOfRepurchaseAgreementsNonTradingTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R59": { "role": "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSTables", "longName": "9955530 - Disclosure - OTHER FINANCIAL LIABILITIES AT FAIR VALUE THROUGH PROFIT OR LOSS (Tables)", "shortName": "OTHER FINANCIAL LIABILITIES AT FAIR VALUE THROUGH PROFIT OR LOSS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "59", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossExplanatoryTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossExplanatoryTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R60": { "role": "http://santander.co.uk/role/DEBTSECURITIESINISSUETables", "longName": "9955531 - Disclosure - DEBT SECURITIES IN ISSUE (Tables)", "shortName": "DEBT SECURITIES IN ISSUE (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "60", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDebtSecuritiesInIssueTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDebtSecuritiesInIssueTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R61": { "role": "http://santander.co.uk/role/PROVISIONSTables", "longName": "9955532 - Disclosure - PROVISIONS (Tables)", "shortName": "PROVISIONS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "61", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R62": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANSTables", "longName": "9955533 - Disclosure - RETIREMENT BENEFIT PLANS (Tables)", "shortName": "RETIREMENT BENEFIT PLANS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "62", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDefinedBenefitPlansExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDefinedBenefitPlansExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R63": { "role": "http://santander.co.uk/role/SUBORDINATEDLIABILITIESTables", "longName": "9955534 - Disclosure - SUBORDINATED LIABILITIES (Tables)", "shortName": "SUBORDINATED LIABILITIES (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "63", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailsOfSubordinatedLiabilitiesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfDetailsOfSubordinatedLiabilitiesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R64": { "role": "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSTables", "longName": "9955535 - Disclosure - CONTINGENT LIABILITIES AND COMMITMENTS (Tables)", "shortName": "CONTINGENT LIABILITIES AND COMMITMENTS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "64", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfCommitmentsContingentLiabilitiesAndGuaranteesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfCommitmentsContingentLiabilitiesAndGuaranteesTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R65": { "role": "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSTables", "longName": "9955536 - Disclosure - OTHER EQUITY INSTRUMENTS (Tables)", "shortName": "OTHER EQUITY INSTRUMENTS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "65", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfSummaryOfOtherEquityInstrumentsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfSummaryOfOtherEquityInstrumentsTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R66": { "role": "http://santander.co.uk/role/FINANCIALINSTRUMENTSTables", "longName": "9955537 - Disclosure - FINANCIAL INSTRUMENTS (Tables)", "shortName": "FINANCIAL INSTRUMENTS (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "66", "firstAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfFairValueOfFinancialInstrumentsAtAmortisedCostTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:DisclosureOfFairValueOfFinancialInstrumentsAtAmortisedCostTableTextBlock", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R67": { "role": "http://santander.co.uk/role/ACQUISITIONOFTSBTables", "longName": "9955538 - Disclosure - ACQUISITION OF TSB (Tables)", "shortName": "ACQUISITION OF TSB (Tables)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "tables", "menuCat": "Tables", "order": "67", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory", "unitRef": null, "xsiNil": "false", "lang": "en-US", "decimals": null, "ancestors": [ "div", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R68": { "role": "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "longName": "9955539 - Disclosure - Credit Risk - Disclosure of Base Expected Credit Losses to Probability Weighted Estimated Credit Losses (Details)", "shortName": "Credit Risk - Disclosure of Base Expected Credit Losses to Probability Weighted Estimated Credit Losses (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "68", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:LoansAndAdvancesToCustomers", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-2", "name": "ifrs-full:LoansAndAdvancesToCustomers", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfBaseExpectedCreditLossesToProbabilityWeightedEstimatedCreditLossesTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R69": { "role": "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "longName": "9955540 - Disclosure - Credit Risk - Disclosure of ECL Reconciliation (Details)", "shortName": "Credit Risk - Disclosure of ECL Reconciliation (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "69", "firstAnchor": { "contextRef": "c-1", "name": "san:FinancialAssetsPostWriteoffRecoveries", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailedInformationOfImpairmentChargesAndProvisionsTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-141", "name": "san:IncreaseDecreaseThroughTransfersFromStageOneToStageTwoFinancialAssets", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R70": { "role": "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails", "longName": "9955541 - Disclosure - Capital Risk - Summary of Regulatory Capital Resources (Details)", "shortName": "Capital Risk - Summary of Regulatory Capital Resources (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "70", "firstAnchor": { "contextRef": "c-177", "name": "san:CommonEquityTierOneCapitalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:CommonEquityTierOneCapitalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R71": { "role": "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails", "longName": "9955542 - Disclosure - Market Risk - Yield Curve Risk (Details)", "shortName": "Market Risk - Yield Curve Risk (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "71", "firstAnchor": { "contextRef": "c-181", "name": "san:IncreaseDecreaseInNetInterestIncomeIfAffectedByBasisPointParallelShift", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-181", "name": "san:IncreaseDecreaseInNetInterestIncomeIfAffectedByBasisPointParallelShift", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R72": { "role": "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "longName": "9955543 - Disclosure - ACCOUNTING POLICIES - Change in accounting policy (Details)", "shortName": "ACCOUNTING POLICIES - Change in accounting policy (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "72", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:RevenueFromInterest", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-234", "name": "ifrs-full:RevenueFromInterest", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "ifrs-full:DescriptionOfVoluntaryChangeInAccountingPolicy", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R73": { "role": "http://santander.co.uk/role/ACCOUNTINGPOLICIESCriticaljudgementsandaccountingestimatesDetails", "longName": "9955544 - Disclosure - ACCOUNTING POLICIES - Critical judgements and accounting estimates (Details)", "shortName": "ACCOUNTING POLICIES - Critical judgements and accounting estimates (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "73", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:Goodwill", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-236", "name": "ifrs-full:Goodwill", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "ix:continuation", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R74": { "role": "http://santander.co.uk/role/SEGMENTSAdditionalInformationDetails", "longName": "9955545 - Disclosure - SEGMENTS - Additional Information (Details)", "shortName": "SEGMENTS - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "74", "firstAnchor": { "contextRef": "c-177", "name": "san:NumberOfSegments", "unitRef": "segment", "xsiNil": "false", "lang": "en-US", "decimals": "INF", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:NumberOfSegments", "unitRef": "segment", "xsiNil": "false", "lang": "en-US", "decimals": "INF", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R75": { "role": "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails", "longName": "9955546 - Disclosure - SEGMENTS - Summary of Results by Segment (Details)", "shortName": "SEGMENTS - Summary of Results by Segment (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "75", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:InterestRevenueExpense", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:NonInterestIncomeExpense", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R76": { "role": "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails", "longName": "9955547 - Disclosure - SEGMENTS - Schedule Of Relationship between Customer Assets and Loans and Advances (Details)", "shortName": "SEGMENTS - Schedule Of Relationship between Customer Assets and Loans and Advances (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "76", "firstAnchor": { "contextRef": "c-177", "name": "san:LoansAndAdvancesToCustomersExcludingIntercompanyBalancesGross", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:LoansAndAdvancesToCustomersExcludingIntercompanyBalancesGross", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R77": { "role": "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails", "longName": "9955548 - Disclosure - OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS - Summary of Operating Expenses Before Credit Impairment Losses, Provisions and Charges (Details)", "shortName": "OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS - Summary of Operating Expenses Before Credit Impairment Losses, Provisions and Charges (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "77", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:EmployeeBenefitsExpense", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:EmployeeBenefitsExpense", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R78": { "role": "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSAdditionalInformationDetails", "longName": "9955549 - Disclosure - OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS - Additional Information (Details)", "shortName": "OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "78", "firstAnchor": { "contextRef": "c-1", "name": "san:IncreaseDecreaseInOperatingExpenses", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:IncreaseDecreaseInOperatingExpenses", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R79": { "role": "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails", "longName": "9955550 - Disclosure - CREDIT IMPAIRMENT CHARGES - Summary of Impairment Losses and Provisions (Details)", "shortName": "CREDIT IMPAIRMENT CHARGES - Summary of Impairment Losses and Provisions (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "79", "firstAnchor": { "contextRef": "c-1", "name": "san:CreditImpairmentChargesWriteBacksOnLoansAndAdvancesToCustomer", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailedInformationOfImpairmentChargesAndProvisionsTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:CreditImpairmentChargesWriteBacksOnLoansAndAdvancesToCustomer", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailedInformationOfImpairmentChargesAndProvisionsTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R80": { "role": "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails", "longName": "9955551 - Disclosure - CREDIT IMPAIRMENT CHARGES - Additional Information (Details)", "shortName": "CREDIT IMPAIRMENT CHARGES - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "80", "firstAnchor": { "contextRef": "c-1", "name": "san:CreditImpairmentLossesOnLoansAndAdvancesToBanks", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "san:CreditImpairmentLossesOnOtherFinancialAssetsAtAmortisedCost", "san:CreditImpairmentLossesOnFinancialAssetsAtFVOCI", "san:CreditImpairmentLossesOnLoansAndAdvancesToBanks", "san:CreditImpairmentLossesOnNonTradingReverseRepurchaseAgreements", "san:CreditImpairmentLossesOnFinancialAssetsAtFVOCI", "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:CreditImpairmentLossesOnLoansAndAdvancesToBanks", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "san:CreditImpairmentLossesOnOtherFinancialAssetsAtAmortisedCost", "san:CreditImpairmentLossesOnFinancialAssetsAtFVOCI", "san:CreditImpairmentLossesOnLoansAndAdvancesToBanks", "san:CreditImpairmentLossesOnNonTradingReverseRepurchaseAgreements", "san:CreditImpairmentLossesOnFinancialAssetsAtFVOCI", "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R81": { "role": "http://santander.co.uk/role/TAXATIONAdditionalInformationDetails", "longName": "9955552 - Disclosure - TAXATION - Additional Information (Details)", "shortName": "TAXATION - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "81", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:AverageEffectiveTaxRate", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "3", "ancestors": [ "span", "san:DisclosureOfReconciliationOfChargeResultingFromApplyingUKCorporationTaxRateExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:AverageEffectiveTaxRate", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "3", "ancestors": [ "span", "san:DisclosureOfReconciliationOfChargeResultingFromApplyingUKCorporationTaxRateExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R82": { "role": "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails", "longName": "9955553 - Disclosure - TAXATION - Schedule of Tax on Profit Before Tax Differs from Theoretical Amount that Arise Using Basic Corporation Tax Rate (Details)", "shortName": "TAXATION - Schedule of Tax on Profit Before Tax Differs from Theoretical Amount that Arise Using Basic Corporation Tax Rate (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "82", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:ApplicableTaxRate", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "2", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:ApplicableTaxRate", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "2", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R83": { "role": "http://santander.co.uk/role/DIVIDENDSONORDINARYSHARESDetails", "longName": "9955554 - Disclosure - DIVIDENDS ON ORDINARY SHARES (Details)", "shortName": "DIVIDENDS ON ORDINARY SHARES (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "83", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:DividendsPaidOrdinaryShares", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:DividendsPaidOrdinaryShares", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R84": { "role": "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "longName": "9955555 - Disclosure - DERIVATIVE FINANCIAL INSTRUMENTS (Details)", "shortName": "DERIVATIVE FINANCIAL INSTRUMENTS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "84", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:NotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-281", "name": "ifrs-full:NotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R85": { "role": "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails", "longName": "9955556 - Disclosure - OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS (Details)", "shortName": "OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "85", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:FinancialAssetsAtFairValueThroughProfitOrLoss", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "ifrs-full:DisclosureOfFinancialInstrumentsDesignatedAtFairValueThroughProfitOrLossExplanatory", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "ifrs-full:FinancialAssetsAtFairValueThroughProfitOrLoss", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "ifrs-full:DisclosureOfFinancialInstrumentsDesignatedAtFairValueThroughProfitOrLossExplanatory", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R86": { "role": "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails", "longName": "9955557 - Disclosure - LOANS AND ADVANCES TO CUSTOMERS (Details)", "shortName": "LOANS AND ADVANCES TO CUSTOMERS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "86", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:LoansAndAdvancesToCustomers", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:ResidualValueAndVoluntaryTerminationProvisions", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfNetLoansAndAdvancesToCustomersTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R87": { "role": "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "longName": "9955558 - Disclosure - SECURITISATIONS AND COVERED BONDS - Additional Information (Details)", "shortName": "SECURITISATIONS AND COVERED BONDS - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "87", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:NotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-363", "name": "san:MortgageBackedNotesSold", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R88": { "role": "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "longName": "9955559 - Disclosure - SECURITISATIONS AND COVERED BONDS - Disclosure of Analysis of Securitisations and Covered Bonds (Details)", "shortName": "SECURITISATIONS AND COVERED BONDS - Disclosure of Analysis of Securitisations and Covered Bonds (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "88", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:NotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-342", "name": "ifrs-full:AssetsRecognisedInEntitysFinancialStatementsInRelationToStructuredEntities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R89": { "role": "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails", "longName": "9955560 - Disclosure - SECURITISATIONS AND COVERED BONDS - Summary of Issuances and Redemptions of Securitisation and Covered Bond Programme (Details)", "shortName": "SECURITISATIONS AND COVERED BONDS - Summary of Issuances and Redemptions of Securitisation and Covered Bond Programme (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "89", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:NotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-359", "name": "san:SecuritisationsAndCoveredBondsIssued", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R90": { "role": "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails", "longName": "9955561 - Disclosure - REVERSE REPURCHASE AGREEMENTS \u2013 NON-TRADING (Details)", "shortName": "REVERSE REPURCHASE AGREEMENTS \u2013 NON-TRADING (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "90", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:ReverseRepurchaseAgreementsAndCashCollateralOnSecuritiesBorrowed", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-364", "name": "ifrs-full:ReverseRepurchaseAgreementsAndCashCollateralOnSecuritiesBorrowed", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "ifrs-full:DisclosureOfRepurchaseAndReverseRepurchaseAgreementsExplanatory", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R91": { "role": "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails", "longName": "9955562 - Disclosure - OTHER FINANCIAL ASSETS AT AMORTISED COST (Details)", "shortName": "OTHER FINANCIAL ASSETS AT AMORTISED COST (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "91", "firstAnchor": { "contextRef": "c-370", "name": "ifrs-full:DebtInstrumentsHeldAtAmortisedCost", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailedInformationOfOtherFinancialAssetsAtAmortisedCostTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-370", "name": "ifrs-full:DebtInstrumentsHeldAtAmortisedCost", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailedInformationOfOtherFinancialAssetsAtAmortisedCostTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R92": { "role": "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails", "longName": "9955563 - Disclosure - INTERESTS IN OTHER ENTITIES (Details)", "shortName": "INTERESTS IN OTHER ENTITIES (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "92", "firstAnchor": { "contextRef": "c-375", "name": "san:NumberOfStructuredEntities", "unitRef": "structuredentities", "xsiNil": "false", "lang": "en-US", "decimals": "INF", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-375", "name": "san:NumberOfStructuredEntities", "unitRef": "structuredentities", "xsiNil": "false", "lang": "en-US", "decimals": "INF", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R93": { "role": "http://santander.co.uk/role/INTANGIBLEASSETSDetails", "longName": "9955564 - Disclosure - INTANGIBLE ASSETS (Details)", "shortName": "INTANGIBLE ASSETS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "93", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:Goodwill", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-376", "name": "ifrs-full:IntangibleAssetsOtherThanGoodwill", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R94": { "role": "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails", "longName": "9955565 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Details)", "shortName": "PROPERTY, PLANT AND EQUIPMENT (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "94", "firstAnchor": { "contextRef": "c-178", "name": "ifrs-full:PropertyPlantAndEquipmentIncludingRightofuseAssets", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "ifrs-full:InvestmentProperty", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R95": { "role": "http://santander.co.uk/role/DEPOSITSBYBANKSDetails", "longName": "9955566 - Disclosure - DEPOSITS BY BANKS (Details)", "shortName": "DEPOSITS BY BANKS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "95", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:DepositsFromBanks", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDepositsByBankTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:DepositsFromBanksSettlementActivities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R96": { "role": "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails", "longName": "9955567 - Disclosure - DEPOSITS BY CUSTOMERS (Details)", "shortName": "DEPOSITS BY CUSTOMERS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "96", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:DepositsFromCustomers", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailedInformationAboutDepositsFromCustomersTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-437", "name": "ifrs-full:DepositsFromCustomers", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailedInformationAboutDepositsFromCustomersTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R97": { "role": "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails", "longName": "9955568 - Disclosure - REPURCHASE AGREEMENTS \u2013 NON-TRADING (Details)", "shortName": "REPURCHASE AGREEMENTS \u2013 NON-TRADING (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "97", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:RepurchaseAgreementsAndCashCollateralOnSecuritiesLent", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DetailedDisclosureOfRepurchaseAgreementsNonTradingTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-364", "name": "ifrs-full:RepurchaseAgreementsAndCashCollateralOnSecuritiesLent", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DetailedDisclosureOfRepurchaseAgreementsNonTradingTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R98": { "role": "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails", "longName": "9955569 - Disclosure - OTHER FINANCIAL LIABILITIES AT FAIR VALUE THROUGH PROFIT OR LOSS (Details)", "shortName": "OTHER FINANCIAL LIABILITIES AT FAIR VALUE THROUGH PROFIT OR LOSS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "98", "firstAnchor": { "contextRef": "c-453", "name": "ifrs-full:FinancialLiabilities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-453", "name": "ifrs-full:FinancialLiabilities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R99": { "role": "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "longName": "9955570 - Disclosure - DEBT SECURITIES IN ISSUE (Details)", "shortName": "DEBT SECURITIES IN ISSUE (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "99", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:NotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-455", "name": "ifrs-full:DebtSecurities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDebtSecuritiesInIssueTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R100": { "role": "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails", "longName": "9955571 - Disclosure - PROVISIONS - Summary of Provisions Reconciliation (Details)", "shortName": "PROVISIONS - Summary of Provisions Reconciliation (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "100", "firstAnchor": { "contextRef": "c-178", "name": "ifrs-full:Provisions", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:UnusedProvisionReversedOtherProvisions", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R101": { "role": "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "longName": "9955572 - Disclosure - PROVISIONS - Additional Information (Details)", "shortName": "PROVISIONS - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "101", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:Provisions", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-500", "name": "san:NumberOfBranchClosures", "unitRef": "branch", "xsiNil": "false", "lang": "en-US", "decimals": "INF", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R102": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails", "longName": "9955573 - Disclosure - RETIREMENT BENEFIT PLANS - Summary of Retirement Benefit Plans (Details)", "shortName": "RETIREMENT BENEFIT PLANS - Summary of Retirement Benefit Plans (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "102", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:LiabilityAssetOfDefinedBenefitPlans", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-519", "name": "ifrs-full:SurplusDeficitInPlan", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R103": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANSAdditionalInformationDetails", "longName": "9955574 - Disclosure - RETIREMENT BENEFIT PLANS - Additional Information (Details)", "shortName": "RETIREMENT BENEFIT PLANS - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "103", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:PostemploymentBenefitExpenseDefinedContributionPlans", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:PostemploymentBenefitExpenseDefinedContributionPlans", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R104": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails", "longName": "9955575 - Disclosure - RETIREMENT BENEFIT PLANS - Summary of Amounts Recognised in Other Comprehensive Income (Details)", "shortName": "RETIREMENT BENEFIT PLANS - Summary of Amounts Recognised in Other Comprehensive Income (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "104", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfAmountsRecognisedInOtherComprehensiveIncomeTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfAmountsRecognisedInOtherComprehensiveIncomeTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R105": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofNetAssetsRecognisedDetails", "longName": "9955576 - Disclosure - RETIREMENT BENEFIT PLANS - Summary of Net Assets Recognised (Details)", "shortName": "RETIREMENT BENEFIT PLANS - Summary of Net Assets Recognised (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "105", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:DefinedBenefitObligationAtPresentValue", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "ifrs-full:DefinedBenefitObligationAtPresentValue", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R106": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails", "longName": "9955577 - Disclosure - RETIREMENT BENEFIT PLANS - Summary of Principal Actuarial Assumptions Used for Defined Benefit Schemes (Details)", "shortName": "RETIREMENT BENEFIT PLANS - Summary of Principal Actuarial Assumptions Used for Defined Benefit Schemes (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "106", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:ActuarialAssumptionOfDiscountRates", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "3", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "ifrs-full:ActuarialAssumptionOfDiscountRates", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "3", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R107": { "role": "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails", "longName": "9955578 - Disclosure - RETIREMENT BENEFIT PLANS - Summary of Actuarial Assumption Sensitivities (Details)", "shortName": "RETIREMENT BENEFIT PLANS - Summary of Actuarial Assumption Sensitivities (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "107", "firstAnchor": { "contextRef": "c-522", "name": "ifrs-full:PercentageOfReasonablyPossibleIncreaseInActuarialAssumption", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "INF", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-522", "name": "ifrs-full:PercentageOfReasonablyPossibleIncreaseInActuarialAssumption", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "INF", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R108": { "role": "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails", "longName": "9955579 - Disclosure - SUBORDINATED LIABILITIES - Schedule of Subordinated Liabilities (Details)", "shortName": "SUBORDINATED LIABILITIES - Schedule of Subordinated Liabilities (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "108", "firstAnchor": { "contextRef": "c-177", "name": "san:SterlingPreferenceSharesNotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "san:SterlingPreferenceSharesNotionalAmount", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailsOfSubordinatedLiabilitiesTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:SterlingPreferenceSharesNotionalAmount", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "san:SterlingPreferenceSharesNotionalAmount", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailsOfSubordinatedLiabilitiesTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R109": { "role": "http://santander.co.uk/role/SUBORDINATEDLIABILITIESAdditionalInformationDetails", "longName": "9955580 - Disclosure - SUBORDINATED LIABILITIES - Additional Information (Details)", "shortName": "SUBORDINATED LIABILITIES - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "109", "firstAnchor": { "contextRef": "c-1", "name": "san:GainLossOnRepurchaseOfSubordinatedLiabilities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "san:GainLossOnRepurchaseOfSubordinatedLiabilities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R110": { "role": "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails", "longName": "9955581 - Disclosure - CONTINGENT LIABILITIES AND COMMITMENTS - Summary of Contingent Liabilities and Commitments (Details)", "shortName": "CONTINGENT LIABILITIES AND COMMITMENTS - Summary of Contingent Liabilities and Commitments (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "110", "firstAnchor": { "contextRef": "c-177", "name": "san:EstimatedFinancialEffectOfContingentLiabilitiesAndCommitments", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfCommitmentsContingentLiabilitiesAndGuaranteesTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "san:EstimatedFinancialEffectOfContingentLiabilitiesAndCommitments", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfCommitmentsContingentLiabilitiesAndGuaranteesTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R111": { "role": "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "longName": "9955582 - Disclosure - CONTINGENT LIABILITIES AND COMMITMENTS - Additional Information (Details)", "shortName": "CONTINGENT LIABILITIES AND COMMITMENTS - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "111", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:Provisions", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-537", "name": "san:PreferredStockIssuedThreshold", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R112": { "role": "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails", "longName": "9955583 - Disclosure - OTHER EQUITY INSTRUMENTS (Details)", "shortName": "OTHER EQUITY INSTRUMENTS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "112", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:OtherEquityInterest", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfSummaryOfOtherEquityInstrumentsTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-540", "name": "san:CapitalSecuritiesIssued", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfSummaryOfOtherEquityInstrumentsTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R113": { "role": "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails", "longName": "9955584 - Disclosure - ASSETS CHARGED AS SECURITY FOR LIABILITIES AND COLLATERAL ACCEPTED AS SECURITY FOR ASSETS (Details)", "shortName": "ASSETS CHARGED AS SECURITY FOR LIABILITIES AND COLLATERAL ACCEPTED AS SECURITY FOR ASSETS (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "113", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:AssetsRecognisedInEntitysFinancialStatementsInRelationToStructuredEntities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-176", "name": "san:IncreaseInAssetsRecognisedInEntitysFinancialStatementsInRelationToStructuredEntities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R114": { "role": "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "longName": "9955585 - Disclosure - FINANCIAL INSTRUMENTS - Disclosure of Analysis of Fair Value of Financial Instruments Carried at Amortised Cost (Details)", "shortName": "FINANCIAL INSTRUMENTS - Disclosure of Analysis of Fair Value of Financial Instruments Carried at Amortised Cost (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "114", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:LoansAndAdvancesToCustomers", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-602", "name": "ifrs-full:FinancialLiabilities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R115": { "role": "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "longName": "9955586 - Disclosure - FINANCIAL INSTRUMENTS - Disclosure of Analysis of Fair Value of Financial Instruments Measured at Fair Value on a Recurring Basis (Details)", "shortName": "FINANCIAL INSTRUMENTS - Disclosure of Analysis of Fair Value of Financial Instruments Measured at Fair Value on a Recurring Basis (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "115", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:FinancialAssetsAtFairValue", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-177", "name": "ifrs-full:FinancialAssetsAtFairValue", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R116": { "role": "http://santander.co.uk/role/FINANCIALINSTRUMENTSAdditionalInformationDetails", "longName": "9955587 - Disclosure - FINANCIAL INSTRUMENTS - Additional Information (Details)", "shortName": "FINANCIAL INSTRUMENTS - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "116", "firstAnchor": { "contextRef": "c-1", "name": "ifrs-full:TransfersOutOfLevel1IntoLevel2OfFairValueHierarchyAssets", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "ifrs-full:TransfersOutOfLevel2IntoLevel1OfFairValueHierarchyAssets", "span", "div", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-1", "name": "ifrs-full:TransfersOutOfLevel1IntoLevel2OfFairValueHierarchyAssets", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "ifrs-full:TransfersOutOfLevel2IntoLevel1OfFairValueHierarchyAssets", "span", "div", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R117": { "role": "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails", "longName": "9955588 - Disclosure - FINANCIAL INSTRUMENTS - Summary of Fair Value Adjustments (Details)", "shortName": "FINANCIAL INSTRUMENTS - Summary of Fair Value Adjustments (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "117", "firstAnchor": { "contextRef": "c-815", "name": "san:FairValueAdjustments", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-815", "name": "san:FairValueAdjustments", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R118": { "role": "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails", "longName": "9955589 - Disclosure - FINANCIAL INSTRUMENTS - Summary of Reconciliation of Fair Value Measurement in Level 3 of the Fair Value Hierarchy (Details)", "shortName": "FINANCIAL INSTRUMENTS - Summary of Reconciliation of Fair Value Measurement in Level 3 of the Fair Value Hierarchy (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "118", "firstAnchor": { "contextRef": "c-178", "name": "ifrs-full:Assets", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-818", "name": "ifrs-full:Assets", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R119": { "role": "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "longName": "9955590 - Disclosure - ACQUISITION OF TSB - Additional Information (Details)", "shortName": "ACQUISITION OF TSB - Additional Information (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "119", "firstAnchor": { "contextRef": "c-177", "name": "ifrs-full:SubordinatedLiabilities", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfDetailsOfSubordinatedLiabilitiesTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-862", "name": "san:PreAcquisitionIntegrationCostsRecognisedInOperatingExpenses", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R120": { "role": "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails", "longName": "9955591 - Disclosure - ACQUISITION OF TSB - Summary of detailed information about business combination (Details)", "shortName": "ACQUISITION OF TSB - Summary of detailed information about business combination (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "120", "firstAnchor": { "contextRef": "c-372", "name": "ifrs-full:CashAndCashEquivalentsRecognisedAsOfAcquisitionDate", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfCashFlowFromAcquisitionTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-837", "name": "ifrs-full:CashAndCashEquivalentsRecognisedAsOfAcquisitionDate", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R121": { "role": "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails", "longName": "9955592 - Disclosure - ACQUISITION OF TSB - Disclosure of significant unobservable inputs used in fair value measurement of assets (Details)", "shortName": "ACQUISITION OF TSB - Disclosure of significant unobservable inputs used in fair value measurement of assets (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "121", "firstAnchor": { "contextRef": "c-854", "name": "san:SensitivityAnalysisForFairValueMeasurementReasonablyPossibleChange", "unitRef": "number", "xsiNil": "false", "lang": "en-US", "decimals": "4", "ancestors": [ "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true }, "uniqueAnchor": { "contextRef": "c-856", "name": "ifrs-full:IncreaseDecreaseInFairValueMeasurementDueToReasonablyPossibleIncreaseInUnobservableInputAssets", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "div", "ix:continuation", "div", "ix:continuation", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "unique": true } }, "R122": { "role": "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails", "longName": "9955593 - Disclosure - ACQUISITION OF TSB - Net cash flow from acquisition (Details)", "shortName": "ACQUISITION OF TSB - Net cash flow from acquisition (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "122", "firstAnchor": { "contextRef": "c-372", "name": "san:CashCashBalancesAtCentralBanksAndOtherDemandDepositsOnAcquisition", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfCashFlowFromAcquisitionTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-372", "name": "san:CashCashBalancesAtCentralBanksAndOtherDemandDepositsOnAcquisition", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "span", "div", "div", "div", "td", "tr", "tbody", "table", "div", "div", "san:DisclosureOfCashFlowFromAcquisitionTableTextBlock", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } }, "R123": { "role": "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATEDetails", "longName": "9955594 - Disclosure - EVENTS AFTER THE BALANCE SHEET DATE (Details)", "shortName": "EVENTS AFTER THE BALANCE SHEET DATE (Details)", "isDefault": "false", "groupType": "disclosure", "subGroupType": "details", "menuCat": "Details", "order": "123", "firstAnchor": { "contextRef": "c-864", "name": "ifrs-full:DividendsPaid", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true }, "uniqueAnchor": { "contextRef": "c-864", "name": "ifrs-full:DividendsPaid", "unitRef": "gbp", "xsiNil": "false", "lang": "en-US", "decimals": "-6", "ancestors": [ "span", "div", "ix:continuation", "div", "div", "body", "html" ], "reportCount": 1, "baseRef": "san-20260630.htm", "first": true, "unique": true } } }, "tag": { "san_AXAFranceMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AXAFranceMember", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "AXA France", "label": "AXA France [Member]", "documentation": "AXA France" } } }, "auth_ref": [] }, "ifrs-full_AccumulatedDepreciationAndAmortisationMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AccumulatedDepreciationAndAmortisationMember", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Accumulated depreciation and impairment:", "label": "Accumulated depreciation and amortisation [member]" } } }, "auth_ref": [ "r10", "r338", "r348", "r349", "r350" ] }, "ifrs-full_AccumulatedImpairmentMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AccumulatedImpairmentMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails", "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Accumulated impairment", "verboseLabel": "Accumulated impairment", "label": "Accumulated impairment [member]" } } }, "auth_ref": [ "r116", "r131", "r237", "r310", "r338", "r348", "r349", "r350" ] }, "ifrs-full_AcquisitiondateFairValueOfTotalConsiderationTransferred": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AcquisitiondateFairValueOfTotalConsiderationTransferred", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Total consideration Paid/Transferred", "label": "Consideration transferred, acquisition-date fair value" } }, "en": { "role": { "documentation": "The fair value, at acquisition date, of the consideration transferred in a business combination. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r107", "r219" ] }, "ifrs-full_AcquisitionrelatedCostsRecognisedAsExpenseForTransactionRecognisedSeparatelyFromAcquisitionOfAssetsAndAssumptionOfLiabilitiesInBusinessCombination": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AcquisitionrelatedCostsRecognisedAsExpenseForTransactionRecognisedSeparatelyFromAcquisitionOfAssetsAndAssumptionOfLiabilitiesInBusinessCombination", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Acquisition-related costs recognised as expense for transaction recognised separately from acquisition of assets and assumption of liabilities in business combination", "label": "Acquisition-related costs recognised as expense for transaction recognised separately from acquisition of assets and assumption of liabilities in business combination" } } }, "auth_ref": [ "r111" ] }, "ifrs-full_AcquisitionsThroughBusinessCombinationsPropertyPlantAndEquipmentIncludingRightofuseAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AcquisitionsThroughBusinessCombinationsPropertyPlantAndEquipmentIncludingRightofuseAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Acquisition of business", "label": "Acquisitions through business combinations, property, plant and equipment including right-of-use assets" } }, "en": { "role": { "documentation": "The increase in property, plant and equipment including right-of-use assets resulting from acquisitions through business combinations. [Refer: Total for all business combinations [member]; Property, plant and equipment including right-of-use assets]" } } }, "auth_ref": [ "r339" ] }, "ifrs-full_ActuarialAssumptionOfDiscountRates": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionOfDiscountRates", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Discount rate for scheme liabilities", "label": "Actuarial assumption of discount rates" } }, "en": { "role": { "documentation": "The discount rate used as the significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r342" ] }, "ifrs-full_ActuarialAssumptionOfDiscountRatesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionOfDiscountRatesMember", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Discount rate", "label": "Actuarial assumption of discount rates [member]" } }, "en": { "role": { "documentation": "This member stands for the discount rates used as actuarial assumptions. [Refer: Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r343" ] }, "ifrs-full_ActuarialAssumptionOfExpectedRatesOfInflation": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionOfExpectedRatesOfInflation", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- General price inflation", "label": "Actuarial assumption of expected rates of inflation" } }, "en": { "role": { "documentation": "The expected rate of inflation that is used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [domain]; Defined benefit obligation, at present value; Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r342" ] }, "ifrs-full_ActuarialAssumptionOfExpectedRatesOfInflationMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionOfExpectedRatesOfInflationMember", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "General price inflation", "label": "Actuarial assumption of expected rates of inflation [member]" } }, "en": { "role": { "documentation": "This member stands for the expected rates of inflation used as actuarial assumptions. [Refer: Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r343" ] }, "ifrs-full_ActuarialAssumptionOfExpectedRatesOfPensionIncreases": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionOfExpectedRatesOfPensionIncreases", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Expected rate of pension increase", "label": "Actuarial assumption of expected rates of pension increases" } }, "en": { "role": { "documentation": "The expected rate of increases in pension that is used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [domain]; Defined benefit obligation, at present value; Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r342" ] }, "ifrs-full_ActuarialAssumptionOfExpectedRatesOfSalaryIncreases": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionOfExpectedRatesOfSalaryIncreases", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- General salary increase", "label": "Actuarial assumption of expected rates of salary increases" } }, "en": { "role": { "documentation": "The expected rate of salary increases used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [domain]; Defined benefit obligation, at present value; Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r342" ] }, "ifrs-full_ActuarialAssumptionOfMortalityRatesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionOfMortalityRatesMember", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Mortality", "label": "Actuarial assumption of mortality rates [member]" } }, "en": { "role": { "documentation": "This member stands for the mortality rates used as actuarial assumptions. [Refer: Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r343" ] }, "ifrs-full_ActuarialAssumptionsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionsAxis", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Actuarial assumptions [axis]", "label": "Actuarial assumptions [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r21" ] }, "ifrs-full_ActuarialAssumptionsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialAssumptionsDomain", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Actuarial assumptions [domain]", "label": "Actuarial assumptions [domain]" } }, "en": { "role": { "documentation": "This member stands for all actuarial assumptions. Actuarial assumptions are the entity\u2019s unbiased and mutually compatible best estimates of the demographic and financial variables that will determine the ultimate cost of providing post-employment benefits. It also represents the standard value for the 'Actuarial assumptions' axis if no other member is used." } } }, "auth_ref": [ "r21" ] }, "ifrs-full_ActuarialGainsLossesArisingFromChangesInDemographicAssumptionsNetDefinedBenefitLiabilityAsset": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialGainsLossesArisingFromChangesInDemographicAssumptionsNetDefinedBenefitLiabilityAsset", "crdr": "debit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails": { "parentTag": "ifrs-full_GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Actuarial gains arising from changes in demographic assumptions", "label": "Decrease (increase) in net defined benefit liability (asset) resulting from actuarial gains (losses) arising from changes in demographic assumptions" } }, "en": { "role": { "documentation": "The decrease (increase) in a net defined benefit liability (asset) resulting from actuarial gains (losses) arising from changes in demographic assumptions that result in remeasurements of the net defined benefit liability (asset). Demographic assumptions deal with matters such as: (a) mortality; (b) rates of employee turnover, disability and early retirement; (c) the proportion of plan members with dependants who will be eligible for benefits; (d) the proportion of plan members who will select each form of payment option available under the plan terms; and (e) claim rates under medical plans. [Refer: Net defined benefit liability (asset)]" } } }, "auth_ref": [ "r15" ] }, "ifrs-full_ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset", "crdr": "debit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails": { "parentTag": "ifrs-full_GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Actuarial gains arising from changes in financial assumptions", "label": "Decrease (increase) in net defined benefit liability (asset) resulting from actuarial gains (losses) arising from changes in financial assumptions" } }, "en": { "role": { "documentation": "The decrease (increase) in a net defined benefit liability (asset) resulting from actuarial gains (losses) arising from changes in financial assumptions that result in remeasurements of the net defined benefit liability (asset). Financial assumptions deal with items such as: (a) the discount rate; (b) benefit levels, excluding any cost of the benefits to be met by employees, and future salary; (c) in the case of medical benefits, future medical costs, including claim handling costs (ie the costs that will be incurred in processing and resolving claims, including legal and adjuster's fees); and (d) taxes payable by the plan on contributions relating to service before the reporting date or on benefits resulting from that service. [Refer: Net defined benefit liability (asset)]" } } }, "auth_ref": [ "r16" ] }, "ifrs-full_ActuarialGainsLossesArisingFromExperienceAdjustmentsNetDefinedBenefitLiabilityAsset": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ActuarialGainsLossesArisingFromExperienceAdjustmentsNetDefinedBenefitLiabilityAsset", "crdr": "debit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails": { "parentTag": "ifrs-full_GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Actuarial (losses) arising from experience adjustments", "label": "Decrease (increase) in net defined benefit liability (asset) resulting from actuarial gains (losses) arising from experience adjustments" } }, "en": { "role": { "documentation": "The decrease (increase) in a net defined benefit liability (asset) resulting from actuarial gains (losses) arising from experience adjustments that result in remeasurements of the net defined benefit liability (asset). Experience adjustments deal with the effects of differences between the previous actuarial assumptions and what has actually occurred. [Refer: Net defined benefit liability (asset)]" } } }, "auth_ref": [ "r341" ] }, "ifrs-full_AdditionalProvisionsOtherProvisions": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AdditionalProvisionsOtherProvisions", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Additional provisions", "label": "Additional provisions, other provisions" } }, "en": { "role": { "documentation": "The amount of additional other provisions made. [Refer: Other provisions]" } } }, "auth_ref": [ "r37", "r201" ] }, "san_AdditionalTier1SecuritiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AdditionalTier1SecuritiesMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "AT1 Securities", "label": "Additional Tier1 Securities [Member]", "documentation": "Additional Tier1 Securities" } } }, "auth_ref": [] }, "san_AdditionalTierOneCapitalAmount": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AdditionalTierOneCapitalAmount", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails": { "parentTag": "san_TierOneCapitalAmount", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "AT1 capital", "label": "Additional Tier One Capital Amount", "documentation": "Additional Tier One Capital Amount" } } }, "auth_ref": [] }, "ifrs-full_AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipmentIncludingRightofuseAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipmentIncludingRightofuseAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Additions", "label": "Additions other than through business combinations, property, plant and equipment including right-of-use assets" } }, "en": { "role": { "documentation": "The amount of additions to property, plant and equipment including right-of-use assets other than those acquired through business combinations. [Refer: Total for all business combinations [member]; Property, plant and equipment including right-of-use assets]" } } }, "auth_ref": [ "r339" ] }, "san_AdjustmentsForDecreaseIncreaseInOperatingAssets": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AdjustmentsForDecreaseIncreaseInOperatingAssets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Change in operating assets", "label": "Adjustments For Decrease (Increase) In Operating Assets", "documentation": "Adjustments For Decrease (Increase) In Operating Assets" } } }, "auth_ref": [] }, "san_AdjustmentsForIncreaseDecreaseInOperatingLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AdjustmentsForIncreaseDecreaseInOperatingLiabilities", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Change in operating liabilities", "label": "Adjustments For Increase (Decrease) In Operating Liabilities", "documentation": "Adjustments For Increase (Decrease) In Operating Liabilities" } } }, "auth_ref": [] }, "san_AdjustmentsForItemsNotClassifiedAsCashAndCashEquivalents": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AdjustmentsForItemsNotClassifiedAsCashAndCashEquivalents", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Adjustments for items not classified as cash and cash equivalents 1", "label": "Adjustments For Items Not Classified As Cash And Cash Equivalents", "documentation": "Adjustments For Items Not Classified As Cash And Cash Equivalents" } } }, "auth_ref": [] }, "ifrs-full_AdjustmentsForReconcileProfitLoss": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AdjustmentsForReconcileProfitLoss", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Non-cash items included in profit", "label": "Adjustments to reconcile profit (loss)" } } }, "auth_ref": [ "r57" ] }, "ifrs-full_AdjustmentsForReconcileProfitLossAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AdjustmentsForReconcileProfitLossAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Adjustments for:", "label": "Adjustments to reconcile profit (loss) [abstract]" } } }, "auth_ref": [] }, "ifrs-full_AdjustmentsForUnrealisedForeignExchangeLossesGains": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AdjustmentsForUnrealisedForeignExchangeLossesGains", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities", "weight": 1.0, "order": 6.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Effects of exchange rate differences", "label": "Adjustments for unrealised foreign exchange losses (gains)" } } }, "auth_ref": [ "r293", "r353" ] }, "san_AggregateOperatingCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AggregateOperatingCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_ProfitLossBeforeTax", "weight": -1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "negatedTotalLabel": "Total credit impairment charges, restructuring and specific provisions", "label": "Aggregate Operating Credit Impairment (Charges)/Write-Backs, Restructuring And specific Provisions", "documentation": "Aggregate Operating Credit Impairment (Charges)/Write-Backs, Restructuring And specific Provisions" } } }, "auth_ref": [] }, "san_AgreementsWithBanksMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AgreementsWithBanksMember", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails", "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Agreements with banks", "label": "Agreements With Banks [Member]", "documentation": "Agreements with banks." } } }, "auth_ref": [] }, "san_AgreementsWithCustomersMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AgreementsWithCustomersMember", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails", "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Agreements with customers", "label": "Agreements With Customers [Member]", "documentation": "Agreements with customer." } } }, "auth_ref": [] }, "san_AllowanceAccountForCreditLossesOfFinancialAssetsForLoansAndAdvancesToCustomers": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AllowanceAccountForCreditLossesOfFinancialAssetsForLoansAndAdvancesToCustomers", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "san_LoansAndAdvancesToCustomersNet", "weight": -1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Loan loss allowance", "label": "Allowance Account For Credit Losses Of Financial Assets For Loans And Advances To Customers", "documentation": "Allowance Account For Credit Losses Of Financial Assets For Loans And Advances To Customers" } } }, "auth_ref": [] }, "dei_AmendmentFlag": { "xbrltype": "booleanItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "AmendmentFlag", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Amendment Flag", "label": "Amendment Flag", "documentation": "Boolean flag that is true when the XBRL content amends previously-filed or accepted submission." } } }, "auth_ref": [] }, "san_AmountsDueToFellowBancoSantanderSubsidiariesAndJointVenturesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AmountsDueToFellowBancoSantanderSubsidiariesAndJointVenturesMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Amounts due to fellow Banco Santander subsidiaries and joint ventures", "label": "Amounts Due To Fellow Banco Santander Subsidiaries And Joint Ventures [Member]", "documentation": "Amounts due to fellow Banco Santander Subsidiaries and Joint ventures." } } }, "auth_ref": [] }, "san_AmountsDueToOtherSantanderUkGroupHoldingsPlcSubsidiariesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AmountsDueToOtherSantanderUkGroupHoldingsPlcSubsidiariesMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Amounts due to other Santander UK Group Holdings plc subsidiaries", "label": "Amounts Due To Other Santander UK Group Holdings Plc Subsidiaries [Member]", "documentation": "58c8bb38-9525-fbf8-00b0-bbaef1f35672" } } }, "auth_ref": [] }, "san_AmountsDueToSantanderUKGroupHoldingsPlcMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AmountsDueToSantanderUKGroupHoldingsPlcMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Amounts due to Santander UK Group Holdings plc", "label": "Amounts Due To Santander UK Group Holdings Plc [Member]", "documentation": "Amounts Due To Santander UK Group Holdings Plc" } } }, "auth_ref": [] }, "san_AmountsDueToSantanderUkSubsidiariesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "AmountsDueToSantanderUkSubsidiariesMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Amounts due to other Santander UK Group Holdings plc subsidiaries", "label": "Amounts Due To Santander UK Subsidiaries [Member]", "documentation": "fb748f7c-9622-7cc6-607e-bbaef20842a7" } } }, "auth_ref": [] }, "ifrs-full_ApplicableTaxRate": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ApplicableTaxRate", "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Applicable tax rate (percentage)", "label": "Applicable tax rate" } }, "en": { "role": { "documentation": "The applicable income tax rate." } } }, "auth_ref": [ "r5", "r184" ] }, "ifrs-full_Assets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Assets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Total assets", "periodStartLabel": "Beginning balance", "periodEndLabel": "Ending Balance", "label": "Assets" } }, "en": { "role": { "documentation": "The amount of a present economic resource controlled by the entity as a result of past events. Economic resource is a right that has the potential to produce economic benefits." } } }, "auth_ref": [ "r85", "r86", "r91", "r154", "r156", "r246", "r247", "r269" ] }, "ifrs-full_AssetsAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AssetsAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Assets", "label": "Assets [abstract]" } } }, "auth_ref": [] }, "ifrs-full_AssetsRecognisedInEntitysFinancialStatementsInRelationToStructuredEntities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AssetsRecognisedInEntitysFinancialStatementsInRelationToStructuredEntities", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Assets recognised in entity's financial statements in relation to structured entities", "verboseLabel": "Gross assets charged as security for liabilities", "label": "Assets recognised in entity's financial statements in relation to structured entities" } }, "en": { "role": { "documentation": "The amount of assets recognised in the entity's financial statements relating to its interests in structured entities. [Refer: Assets; Total for all unconsolidated structured entities [member]]" } } }, "auth_ref": [ "r77" ] }, "ifrs-full_AtFairValueMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AtFairValueMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair value", "verboseLabel": "Fair Value at 30 April 2026", "label": "At fair value [member]" } }, "en": { "role": { "documentation": "This member stands for measurement based on fair value. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date." } } }, "auth_ref": [ "r50", "r54", "r76", "r85", "r214", "r245", "r246" ] }, "ifrs-full_AverageEffectiveTaxRate": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "AverageEffectiveTaxRate", "presentation": [ "http://santander.co.uk/role/TAXATIONAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Effective tax rate (percentage)", "label": "Average effective tax rate" } }, "en": { "role": { "documentation": "The tax expense (income) divided by the accounting profit. [Refer: Accounting profit]" } } }, "auth_ref": [ "r5", "r184" ] }, "ifrs-full_BankBalancesAtCentralBanksOtherThanMandatoryReserveDeposits": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "BankBalancesAtCentralBanksOtherThanMandatoryReserveDeposits", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashAndCashEquivalents", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash and bank balances at central banks less regulatory minimum cash balances", "label": "Bank balances at central banks other than mandatory reserve deposits" } }, "en": { "role": { "documentation": "The amount of bank balances held at central banks other than mandatory reserve deposits. [Refer: Mandatory reserve deposits at central banks]" } } }, "auth_ref": [ "r361" ] }, "san_BankLevyMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BankLevyMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Bank Levy", "label": "Bank Levy [Member]", "documentation": "Bank Levy" } } }, "auth_ref": [] }, "san_BankOfEnglandMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BankOfEnglandMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Bank of England", "label": "Bank of England [Member]", "documentation": "Bank of England" } } }, "auth_ref": [] }, "san_BaseCaseScenarioMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BaseCaseScenarioMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Base case", "label": "Base Case Scenario [Member]", "documentation": "Base case." } } }, "auth_ref": [] }, "ifrs-full_BestEstimateAtAcquisitionDateOfContractualCashFlowsNotExpectedToBeCollectedForAcquiredReceivables": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "BestEstimateAtAcquisitionDateOfContractualCashFlowsNotExpectedToBeCollectedForAcquiredReceivables", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Best estimate at acquisition date of contractual cash flows not expected to be collected for acquired receivables", "label": "Best estimate at acquisition date of contractual cash flows not expected to be collected for acquired receivables" } }, "en": { "role": { "documentation": "The best estimate at acquisition date of contractual cash flows not expected to be collected for receivables acquired in business combinations. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r110" ] }, "san_BidOfferAndTradeSpecificRiskRelatedAdjustmentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BidOfferAndTradeSpecificRiskRelatedAdjustmentsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Bid-offer and trade specific adjustments", "label": "Bid Offer And Trade Specific Risk Related Adjustments [Member]", "documentation": "Bid-offer and trade specific adjustments." } } }, "auth_ref": [] }, "ifrs-full_BottomOfRangeMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "BottomOfRangeMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Minimum", "label": "Bottom of range [member]" } }, "en": { "role": { "documentation": "This member stands for the bottom of a range." } } }, "auth_ref": [ "r62", "r94", "r103", "r105", "r172", "r296", "r298", "r358" ] }, "san_BranchTransformationProjectMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BranchTransformationProjectMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Branch Transformation Project", "label": "Branch Transformation Project [Member]", "documentation": "Branch Transformation Project" } } }, "auth_ref": [] }, "ifrs-full_BrandNamesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "BrandNamesMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Brand names", "label": "Brand names [member]" } }, "en": { "role": { "documentation": "This member stands for a class of intangible assets representing rights to a group of complementary assets such as a trademark (or service mark) and its related trade name, formulas, recipes and technological expertise. [Refer: Intangible assets other than goodwill]" } } }, "auth_ref": [ "r289" ] }, "san_BusinessCombinationConsiderationTransferredAT1SecuritiesAndOther": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BusinessCombinationConsiderationTransferredAT1SecuritiesAndOther", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Non-equity securities purchased", "label": "Business Combination Consideration Transferred AT1 Securities And Other", "documentation": "Business Combination Consideration Transferred AT1 Securities And Other" } } }, "auth_ref": [] }, "san_BusinessCombinationFairValueMeasurementAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BusinessCombinationFairValueMeasurementAxis", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Business Combination, Fair Value Measurement [Axis]", "label": "Business Combination, Fair Value Measurement [Axis]", "documentation": "Carrying Amount And Fair Value" } } }, "auth_ref": [] }, "san_BusinessCombinationFairValueMeasurementDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BusinessCombinationFairValueMeasurementDomain", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Business Combination, Fair Value Measurement [Domain]", "label": "Business Combination, Fair Value Measurement [Domain]", "documentation": "Business Combination, Fair Value Measurement [Domain]" } } }, "auth_ref": [] }, "san_BusinessCombinationsAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "BusinessCombinationsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Business Combinations [Abstract]", "label": "Business Combinations [Abstract]", "documentation": "Business Combinations [Abstract]" } } }, "auth_ref": [] }, "ifrs-full_BusinessCombinationsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "BusinessCombinationsAxis", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESCriticaljudgementsandaccountingestimatesDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails", "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails", "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails", "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Business combinations [axis]", "label": "Business combinations [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r114", "r220" ] }, "ifrs-full_BusinessCombinationsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "BusinessCombinationsDomain", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESCriticaljudgementsandaccountingestimatesDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails", "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails", "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails", "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Business combinations [domain]", "label": "Business combinations [domain]" } }, "en": { "role": { "documentation": "This member stands for the standard value for the 'Business combinations' axis if no other member is used." } } }, "auth_ref": [ "r114", "r117", "r220" ] }, "san_CDIImpactMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CDIImpactMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impact on CDI", "label": "CDI Impact [Member]", "documentation": "CDI Impact" } } }, "auth_ref": [] }, "san_CapitalAmountGuaranteedOrProtectedInRespectOfEquityIndexLinkedDeposits": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CapitalAmountGuaranteedOrProtectedInRespectOfEquityIndexLinkedDeposits", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Capital amount guaranteed or protected", "label": "Capital Amount Guaranteed Or Protected In Respect Of Equity Index Linked Deposits", "documentation": "Capital Amount Guaranteed Or Protected In Respect Of Equity Index Linked Deposits" } } }, "auth_ref": [] }, "ifrs-full_CapitalReserveMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CapitalReserveMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Capital contribution reserve", "label": "Capital reserve [member]" } }, "en": { "role": { "documentation": "This member stands for a component of equity representing capital reserves." } } }, "auth_ref": [ "r360" ] }, "san_CapitalSecuritiesIssued": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CapitalSecuritiesIssued", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Capital securities", "label": "Capital Securities Issued", "documentation": "Capital securities issued." } } }, "auth_ref": [] }, "ifrs-full_CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails", "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis]", "label": "Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r7", "r8", "r45", "r46", "r51", "r52", "r53", "r54", "r55", "r116", "r131", "r132", "r185", "r186", "r208", "r209", "r211", "r212", "r213", "r214", "r215", "r221", "r237", "r239" ] }, "ifrs-full_CarryingAmountMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CarryingAmountMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails", "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails", "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Carrying amount", "verboseLabel": "Book value at 30 April 2026", "label": "Carrying amount [member]" } } }, "auth_ref": [ "r8", "r46", "r51", "r53", "r54", "r116", "r131", "r132", "r186", "r209", "r211", "r213", "r214", "r221", "r237", "r239" ] }, "ifrs-full_CashAndBankBalancesAtCentralBanks": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashAndBankBalancesAtCentralBanks", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 5.0 }, "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash and balances at central banks", "totalLabel": "Cash and balances at central banks", "label": "Cash and bank balances at central banks" } }, "en": { "role": { "documentation": "The amount of cash and bank balances held at central banks." } } }, "auth_ref": [ "r364" ] }, "ifrs-full_CashAndCashEquivalents": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashAndCashEquivalents", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "periodStartLabel": "Cash and cash equivalents at beginning of the year", "periodEndLabel": "Cash and cash equivalents at the end of the period", "totalLabel": "Cash and cash equivalents at the end of the period", "label": "Cash and cash equivalents" } }, "en": { "role": { "documentation": "The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents]" } } }, "auth_ref": [ "r63", "r80", "r173", "r266" ] }, "ifrs-full_CashAndCashEquivalentsIfDifferentFromStatementOfFinancialPositionAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashAndCashEquivalentsIfDifferentFromStatementOfFinancialPositionAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash and cash equivalents consist of:", "label": "Cash and cash equivalents if different from statement of financial position [abstract]" } } }, "auth_ref": [] }, "ifrs-full_CashAndCashEquivalentsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashAndCashEquivalentsRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails": { "parentTag": "san_NetCashFlowFromAcquisition", "weight": -1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Cash and balances at central banks", "verboseLabel": "Cash and cash equivalents acquired", "label": "Cash and cash equivalents recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for cash and cash equivalents acquired in a business combination. [Refer: Cash and cash equivalents; Total for all business combinations [member]]" } } }, "auth_ref": [ "r357" ] }, "san_CashCashBalancesAtCentralBanksAndOtherDemandDepositsOnAcquisition": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CashCashBalancesAtCentralBanksAndOtherDemandDepositsOnAcquisition", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Cash, cash balances at central banks and other demand deposits on acquisition", "label": "Cash, Cash Balances At Central Banks And Other Demand Deposits On Acquisition", "documentation": "Cash, Cash Balances At Central Banks And Other Demand Deposits On Acquisition" } } }, "auth_ref": [] }, "ifrs-full_CashCollateralPledgedSubjectToEnforceableMasterNettingArrangementOrSimilarAgreementNotSetOffAgainstFinancialLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashCollateralPledgedSubjectToEnforceableMasterNettingArrangementOrSimilarAgreementNotSetOffAgainstFinancialLiabilities", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Collateral cash", "label": "Cash collateral pledged subject to enforceable master netting arrangement or similar agreement not set off against financial liabilities" } }, "en": { "role": { "documentation": "The amount of cash collateral pledged that is subject to an enforceable master netting arrangement or similar agreement and that is not set off against financial liabilities. [Refer: Financial liabilities]" } } }, "auth_ref": [ "r304", "r315" ] }, "ifrs-full_CashCollateralReceivedSubjectToEnforceableMasterNettingArrangementOrSimilarAgreementNotSetOffAgainstFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashCollateralReceivedSubjectToEnforceableMasterNettingArrangementOrSimilarAgreementNotSetOffAgainstFinancialAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Cash collateral received subject to enforceable master netting arrangement or similar agreement not set off against financial assets", "label": "Cash collateral received subject to enforceable master netting arrangement or similar agreement not set off against financial assets" } }, "en": { "role": { "documentation": "The amount of cash collateral received that is subject to an enforceable master netting arrangement or similar agreement and that is not set off against financial assets. [Refer: Financial assets]" } } }, "auth_ref": [ "r304", "r315" ] }, "ifrs-full_CashFlowHedgesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowHedgesAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash flow hedges:", "label": "Cash flow hedges [abstract]" } } }, "auth_ref": [] }, "ifrs-full_CashFlowHedgesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowHedgesMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Designated as cash flow hedges:", "label": "Cash flow hedges [member]" } }, "en": { "role": { "documentation": "This member stands for hedges of the exposure to variability in cash flows that (a) are attributable to a particular risk associated with a recognised asset or liability (such as all or some future interest payments on variable rate debt) or a highly probable forecast transaction; and (b) could affect profit or loss. [Refer: Types of hedges [domain]]" } } }, "auth_ref": [ "r49", "r124", "r125", "r126", "r231", "r232", "r233" ] }, "ifrs-full_CashFlowsFromUsedInFinancingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowsFromUsedInFinancingActivities", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Net cash flows from financing activities", "label": "Cash flows from (used in) financing activities" } }, "en": { "role": { "documentation": "The cash flows from (used in) financing activities, which are activities that result in changes in the size and composition of the contributed equity and borrowings of the entity, from continuing and discontinued operations." } } }, "auth_ref": [ "r56", "r64" ] }, "ifrs-full_CashFlowsFromUsedInFinancingActivitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowsFromUsedInFinancingActivitiesAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash flows from financing activities", "label": "Cash flows from (used in) financing activities [abstract]" } } }, "auth_ref": [] }, "ifrs-full_CashFlowsFromUsedInInvestingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowsFromUsedInInvestingActivities", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Net cash flows from investing activities", "label": "Cash flows from (used in) investing activities" } }, "en": { "role": { "documentation": "The cash flows from (used in) investing activities, which are the acquisition and disposal of long-term assets and other investments not included in cash equivalents, from continuing and discontinued operations." } } }, "auth_ref": [ "r56", "r64" ] }, "ifrs-full_CashFlowsFromUsedInInvestingActivitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowsFromUsedInInvestingActivitiesAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash flows from investing activities", "label": "Cash flows from (used in) investing activities [abstract]" } } }, "auth_ref": [] }, "ifrs-full_CashFlowsFromUsedInOperatingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowsFromUsedInOperatingActivities", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Net cash flows from operating activities", "label": "Cash flows from (used in) operating activities" } } }, "auth_ref": [ "r56", "r64" ] }, "ifrs-full_CashFlowsFromUsedInOperatingActivitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowsFromUsedInOperatingActivitiesAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash flows from operating activities", "label": "Cash flows from (used in) operating activities [abstract]" } } }, "auth_ref": [] }, "ifrs-full_CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities", "weight": -1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Net cash flow from acquisition of TSB Banking Group plc", "label": "Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities" } }, "en": { "role": { "documentation": "The aggregate cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities. [Refer: Total for all subsidiaries [member]]" } } }, "auth_ref": [ "r60" ] }, "san_CashPaidForAT1Securities": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CashPaidForAT1Securities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails": { "parentTag": "san_NetCashFlowFromAcquisition", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Cash paid for AT1 securities", "label": "Cash Paid For AT1 Securities", "documentation": "Cash Paid For AT1 Securities" } } }, "auth_ref": [] }, "san_CashPaidForDebtSecurities": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CashPaidForDebtSecurities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails": { "parentTag": "san_NetCashFlowFromAcquisition", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Cash paid for debt securities", "label": "Cash Paid For Debt Securities", "documentation": "Cash Paid For Debt Securities" } } }, "auth_ref": [] }, "san_CashPaidForOrdinaryShares": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CashPaidForOrdinaryShares", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails": { "parentTag": "san_NetCashFlowFromAcquisition", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Cash paid for ordinary shares", "label": "Cash Paid For Ordinary Shares", "documentation": "Cash Paid For Ordinary Shares" } } }, "auth_ref": [] }, "ifrs-full_CategoriesOfFinancialAssetsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CategoriesOfFinancialAssetsAxis", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Categories of financial assets [axis]", "label": "Categories of financial assets [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r146", "r227" ] }, "ifrs-full_CategoriesOfFinancialAssetsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CategoriesOfFinancialAssetsDomain", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Categories of financial assets [domain]", "label": "Categories of financial assets [domain]" } }, "en": { "role": { "documentation": "This member stands for aggregated categories of financial assets. It also represents the standard value for the 'Categories of financial assets' axis if no other member is used. [Refer: Financial assets]" } } }, "auth_ref": [ "r146", "r227" ] }, "ifrs-full_CategoriesOfFinancialLiabilitiesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CategoriesOfFinancialLiabilitiesAxis", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails", "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Categories of financial liabilities [axis]", "label": "Categories of financial liabilities [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r146", "r227" ] }, "ifrs-full_CategoriesOfFinancialLiabilitiesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CategoriesOfFinancialLiabilitiesDomain", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails", "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Categories of financial liabilities [domain]", "label": "Categories of financial liabilities [domain]" } }, "en": { "role": { "documentation": "This member stands for aggregated categories of financial liabilities. It also represents the standard value for the 'Categories of financial liabilities' axis if no other member is used. [Refer: Financial assets]" } } }, "auth_ref": [ "r146", "r227" ] }, "ifrs-full_CategoriesOfRelatedPartiesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CategoriesOfRelatedPartiesAxis", "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Categories of related parties [axis]", "label": "Categories of related parties [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r25", "r193" ] }, "ifrs-full_CategoriesOfRelatedPartiesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CategoriesOfRelatedPartiesDomain", "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Categories of related parties", "label": "Categories of related parties [domain]" } }, "en": { "role": { "documentation": "This member stands for the standard value for the 'Categories of related parties' axis if no other member is used." } } }, "auth_ref": [ "r25", "r193" ] }, "san_CertificateOfDepositMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CertificateOfDepositMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Certificates of deposit", "label": "Certificate Of Deposit [Member]", "documentation": "Certificate of deposit." } } }, "auth_ref": [] }, "san_ChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiabilityAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiabilityAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Own credit adjustment:", "label": "Change In Fair Value Of Financial Liability Attributable To Change In Credit Risk Of Liability [Abstract]", "documentation": "Change in fair value of financial liability attributable to change in credit risk of liability." } } }, "auth_ref": [] }, "ifrs-full_ClassesOfAssetsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfAssetsAxis", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of assets [axis]", "label": "Classes of assets [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r31", "r32", "r93", "r100", "r168", "r197", "r249" ] }, "ifrs-full_ClassesOfAssetsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfAssetsDomain", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of assets [domain]", "label": "Classes of assets [domain]" } }, "en": { "role": { "documentation": "This member stands for a present economic resource controlled by the entity as a result of past events. Economic resource is a right that has the potential to produce economic benefits. It also represents the standard value for the 'Classes of assets' axis if no other member is used." } } }, "auth_ref": [ "r31", "r93", "r100", "r168", "r197", "r249" ] }, "ifrs-full_ClassesOfContingentLiabilitiesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfContingentLiabilitiesAxis", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of contingent liabilities [axis]", "label": "Classes of contingent liabilities [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r42", "r115", "r206" ] }, "ifrs-full_ClassesOfContingentLiabilitiesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfContingentLiabilitiesDomain", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of contingent liabilities [domain]", "label": "Classes of contingent liabilities [domain]" } }, "en": { "role": { "documentation": "This member stands for possible obligations that arise from past events and whose existence will be confirmed only by the occurrence or non-occurrence of one or more uncertain future events not wholly within the control of the entity; or, present obligations that arise from past events but are not recognised because (a) it is probable that an outflow of resources embodying economic benefits will be required to settle the obligations; or (b) the amount of the obligations cannot be measured with sufficient reliability. It also represents the standard value for the 'Classes of contingent liabilities' axis if no other member is used." } } }, "auth_ref": [ "r43", "r115" ] }, "ifrs-full_ClassesOfFinancialAssetsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfFinancialAssetsAxis", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails", "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of financial assets [axis]", "label": "Classes of financial assets [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r104", "r139", "r140", "r163", "r164", "r254" ] }, "ifrs-full_ClassesOfFinancialAssetsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfFinancialAssetsDomain", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails", "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of financial assets", "label": "Classes of financial assets [domain]" } }, "en": { "role": { "documentation": "This member stands for aggregated classes of financial assets. It also represents the standard value for the 'Classes of financial assets' axis if no other member is used. [Refer: Financial assets]" } } }, "auth_ref": [ "r104", "r139", "r140", "r163", "r164", "r254" ] }, "ifrs-full_ClassesOfFinancialInstrumentsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfFinancialInstrumentsAxis", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of financial instruments [axis]", "label": "Classes of financial instruments [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r131", "r133", "r137", "r138", "r237", "r243" ] }, "ifrs-full_ClassesOfFinancialInstrumentsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfFinancialInstrumentsDomain", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of financial instruments [domain]", "label": "Classes of financial instruments [domain]" } }, "en": { "role": { "documentation": "This member stands for aggregated classes of financial instruments. Financial instruments are contracts that give rise to a financial asset of one entity and a financial liability or equity instrument of another entity. It also represents the standard value for the 'Classes of financial instruments' axis if no other member is used. [Refer: Financial assets; Financial liabilities]" } } }, "auth_ref": [ "r131", "r133", "r137", "r138", "r237", "r243" ] }, "ifrs-full_ClassesOfFinancialLiabilitiesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfFinancialLiabilitiesAxis", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/DEPOSITSBYBANKSDetails", "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of financial liabilities [axis]", "label": "Classes of financial liabilities [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r139", "r140", "r163", "r164" ] }, "ifrs-full_ClassesOfFinancialLiabilitiesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfFinancialLiabilitiesDomain", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/DEPOSITSBYBANKSDetails", "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of financial liabilities [domain]", "label": "Classes of financial liabilities [domain]" } }, "en": { "role": { "documentation": "This member stands for aggregated classes financial liabilities. It also represents the standard value for the 'Classes of financial liabilities' axis if no other member is used. [Refer: Financial liabilities]" } } }, "auth_ref": [ "r139", "r140", "r163", "r164" ] }, "ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfIntangibleAssetsOtherThanGoodwillAxis", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of intangible assets other than goodwill [axis]", "label": "Classes of intangible assets other than goodwill [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r47", "r210" ] }, "ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfIntangibleAssetsOtherThanGoodwillDomain", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of intangible assets other than goodwill [domain]", "label": "Classes of intangible assets other than goodwill [domain]" } }, "en": { "role": { "documentation": "This member stands for the standard value for the 'Classes of intangible assets other than goodwill' axis if no other member is used." } } }, "auth_ref": [ "r47", "r210" ] }, "ifrs-full_ClassesOfLiabilitiesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfLiabilitiesAxis", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of liabilities [axis]", "label": "Classes of liabilities [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r93", "r249" ] }, "ifrs-full_ClassesOfLiabilitiesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfLiabilitiesDomain", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of liabilities [domain]", "label": "Classes of liabilities [domain]" } }, "en": { "role": { "documentation": "This member stands for a present obligation of the entity to transfer an economic resource as a result of past events. Economic resource is a right that has the potential to produce economic benefits. It also represents the standard value for the 'Classes of liabilities' axis if no other member is used. [Refer: Liabilities]" } } }, "auth_ref": [ "r93", "r249" ] }, "ifrs-full_ClassesOfOtherProvisionsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfOtherProvisionsDomain", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of other provisions [domain]", "label": "Classes of other provisions [domain]" } }, "en": { "role": { "documentation": "This member stands for provisions other than provisions for employee benefits. It also represents the standard value for the 'Classes of other provisions' axis if no other member is used. [Refer: Provisions]" } } }, "auth_ref": [ "r40", "r204" ] }, "ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfPropertyPlantAndEquipmentAxis", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of property, plant and equipment [axis]", "label": "Classes of property, plant and equipment [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r9", "r187" ] }, "ifrs-full_ClassesOfPropertyPlantAndEquipmentDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfPropertyPlantAndEquipmentDomain", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of property, plant and equipment [domain]", "label": "Classes of property, plant and equipment [domain]" } }, "en": { "role": { "documentation": "This member stands for the standard value for the 'Classes of property, plant and equipment' axis if no other member is used." } } }, "auth_ref": [ "r9", "r187" ] }, "ifrs-full_ClassesOfProvisionsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ClassesOfProvisionsAxis", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Classes of other provisions [axis]", "label": "Classes of other provisions [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r40", "r204" ] }, "san_CollateralsAndGuaranteesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CollateralsAndGuaranteesMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Zero Amortising Guaranteed Notes", "label": "Collaterals And Guarantees [Member]", "documentation": "Collaterals and guarantees." } } }, "auth_ref": [] }, "san_CommonEquityTierOneCapitalAmount": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CommonEquityTierOneCapitalAmount", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails": { "parentTag": "san_TierOneCapitalAmount", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "CET1 capital", "label": "Common Equity Tier One Capital Amount", "documentation": "Common Equity Tier One Capital Amount" } } }, "auth_ref": [] }, "ifrs-full_ComponentsOfEquityAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ComponentsOfEquityAxis", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Components of equity [axis]", "label": "Components of equity [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r261" ] }, "ifrs-full_ComponentsOfEquityDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ComponentsOfEquityDomain", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Components of equity [domain]", "label": "Components of equity [domain]" } }, "en": { "role": { "documentation": "This member stands for the residual interest in the assets of the entity after deducting all its liabilities. It also represents the standard value for the 'Components of equity' axis if no other member is used." } } }, "auth_ref": [ "r261" ] }, "ifrs-full_ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other comprehensive (expense)/income that may be reclassified to profit or loss subsequently:", "label": "Components of other comprehensive income that will be reclassified to profit or loss, net of tax [abstract]" } } }, "auth_ref": [] }, "ifrs-full_ComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTaxAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTaxAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other comprehensive (expense)/income that will not be reclassified to profit or loss subsequently:", "label": "Components of other comprehensive income that will not be reclassified to profit or loss, net of tax [abstract]" } } }, "auth_ref": [] }, "san_ComponentsOfRegulatoryCapitalAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ComponentsOfRegulatoryCapitalAxis", "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Components Of Regulatory Capital [Axis]", "label": "Components Of Regulatory Capital [axis]", "documentation": "Components of regulatory capital." } } }, "auth_ref": [] }, "san_ComponentsOfRegulatoryCapitalDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ComponentsOfRegulatoryCapitalDomain", "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Components Of Regulatory Capital [Domain]", "label": "Components Of Regulatory Capital [Domain]", "documentation": "Components Of Regulatory Capital [Domain]" } } }, "auth_ref": [] }, "ifrs-full_ComprehensiveIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ComprehensiveIncome", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Total comprehensive income", "label": "Comprehensive income" } }, "en": { "role": { "documentation": "The amount of change in equity resulting from transactions and other events, other than those changes resulting from transactions with owners in their capacity as owners." } } }, "auth_ref": [ "r72", "r74", "r78", "r195", "r217", "r256", "r274", "r294" ] }, "ifrs-full_ComputerSoftwareMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ComputerSoftwareMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/INTANGIBLEASSETSDetails", "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Computer software", "label": "Computer software [member]" } }, "en": { "role": { "documentation": "This member stands for a class of intangible assets representing computer software. [Refer: Intangible assets other than goodwill]" } } }, "auth_ref": [ "r290" ] }, "ifrs-full_ConsiderationPaidReceived": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ConsiderationPaidReceived", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Consideration paid (received)", "label": "Consideration paid (received)" } }, "en": { "role": { "documentation": "The amount of consideration paid or received in respect of both obtaining and losing control of subsidiaries or other businesses. [Refer: Total for all subsidiaries [member]]" } } }, "auth_ref": [ "r61" ] }, "san_ConsiderationPaidReceivedTNAVVariation": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ConsiderationPaidReceivedTNAVVariation", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Consideration paid (received), TNAV variation", "label": "Consideration Paid (Received), TNAV Variation", "documentation": "Consideration Paid (Received), TNAV Variation" } } }, "auth_ref": [] }, "san_ConsumerFinanceMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ConsumerFinanceMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Consumer Finance", "label": "Consumer Finance [member]", "documentation": "Consumer finance." } } }, "auth_ref": [] }, "ifrs-full_ContingentLiabilityForGuaranteesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ContingentLiabilityForGuaranteesMember", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Guarantees given to third parties", "label": "Contingent liability for guarantees [member]" } }, "en": { "role": { "documentation": "This member stands for a contingent liability for guarantees. [Refer: Classes of contingent liabilities [domain]; Guarantees [member]]" } } }, "auth_ref": [ "r347" ] }, "ifrs-full_ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfTransferAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfTransferAxis", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Continuing involvement in derecognised financial assets by type of transfer [axis]", "label": "Continuing involvement in derecognised financial assets by type of transfer [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r312" ] }, "ifrs-full_ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfTransferDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfTransferDomain", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Continuing involvement in derecognised financial assets by type of transfer [domain]", "label": "Continuing involvement in derecognised financial assets by type of transfer [domain]" } }, "en": { "role": { "documentation": "This member stands for all types of transfers of financial instruments. It also represents the standard value for the 'Continuing involvement in derecognised financial assets by type of transfer' axis if no other member is used." } } }, "auth_ref": [ "r312" ] }, "san_CoreDepositIntangiblesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CoreDepositIntangiblesMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Core deposit intangibles", "label": "Core Deposit Intangibles [Member]", "documentation": "Core Deposit Intangibles" } } }, "auth_ref": [] }, "san_CorporateAndCommercialBankingMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CorporateAndCommercialBankingMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Corporate & Commercial Banking", "label": "Corporate And Commercial Banking [Member]", "documentation": "Corporate and commercial banking." } } }, "auth_ref": [] }, "san_CorporateCentreMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CorporateCentreMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Corporate Centre", "label": "Corporate Centre [Member]", "documentation": "Corporate centre." } } }, "auth_ref": [] }, "ifrs-full_CostOfHedgingAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CostOfHedgingAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cost of hedging:", "label": "Cost of hedging [abstract]" } } }, "auth_ref": [] }, "san_CounterFreeBranchesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CounterFreeBranchesMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Counter free branches", "label": "Counter Free Branches [Member]", "documentation": "Counter Free Branches" } } }, "auth_ref": [] }, "srt_CounterpartyNameAxis": { "xbrltype": "stringItemType", "nsuri": "http://fasb.org/srt/2025", "localname": "CounterpartyNameAxis", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Counterparty Name [Axis]", "label": "Counterparty Name [Axis]" } } }, "auth_ref": [] }, "dei_CoverAbstract": { "xbrltype": "stringItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "CoverAbstract", "lang": { "en-us": { "role": { "terseLabel": "Cover [Abstract]", "label": "Cover [Abstract]", "documentation": "Cover page." } } }, "auth_ref": [] }, "san_CoveredBondProgrammesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CoveredBondProgrammesMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Covered bond programme:", "verboseLabel": "Covered bond programme:", "label": "Covered Bond Programmes [Member]", "documentation": "Covered Bond Programmes [member]" } } }, "auth_ref": [] }, "san_CoveredBondsIssued": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CoveredBondsIssued", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Covered bonds issued", "label": "Covered Bonds Issued", "documentation": "Covered Bonds Issued" } } }, "auth_ref": [] }, "san_CoveredBondsRedeemed": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CoveredBondsRedeemed", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Covered bonds redeemed", "label": "Covered Bonds Redeemed", "documentation": "Covered Bonds Redeemed" } } }, "auth_ref": [] }, "san_CreditBalancesInOtherCurrentReceivables": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditBalancesInOtherCurrentReceivables", "crdr": "debit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_LoansAndAdvancesToCustomers", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other item, credit balances in other current receivables", "label": "Credit Balances In Other Current Receivables", "documentation": "Credit Balances In Other Current Receivables" } } }, "auth_ref": [] }, "san_CreditImpairmentChargesWriteBacksOnLoansAndAdvancesToCustomer": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditImpairmentChargesWriteBacksOnLoansAndAdvancesToCustomer", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails": { "parentTag": "ifrs-full_ImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Loans and advances to customers", "label": "Credit Impairment Charges (Write-Backs) On Loans And Advances To Customer", "documentation": "Credit impairment losses on loans and advances to customer." } } }, "auth_ref": [] }, "san_CreditImpairmentLosses": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditImpairmentLosses", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Credit impairment losses", "label": "Credit Impairment Losses", "documentation": "Credit Impairment Losses" } } }, "auth_ref": [] }, "san_CreditImpairmentLossesOnFinancialAssetsAtFVOCI": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditImpairmentLossesOnFinancialAssetsAtFVOCI", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impairment losses on financial assets at FVOCI", "label": "Credit Impairment Losses On Financial Assets At FVOCI", "documentation": "Credit impairment losses on financial assets at FVOCI." } } }, "auth_ref": [] }, "san_CreditImpairmentLossesOnLoansAndAdvancesToBanks": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditImpairmentLossesOnLoansAndAdvancesToBanks", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impairment losses on loans and advances to banks", "label": "Credit Impairment Losses On Loans And Advances To Banks", "documentation": "Credit impairment losses on loans and advances to banks." } } }, "auth_ref": [] }, "san_CreditImpairmentLossesOnNonTradingReverseRepurchaseAgreements": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditImpairmentLossesOnNonTradingReverseRepurchaseAgreements", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impairment losses on non-trading reverse repurchase agreements", "label": "Credit Impairment Losses On Non-Trading Reverse Repurchase Agreements", "documentation": "Credit impairment losses on non-trading reverse repurchase agreements." } } }, "auth_ref": [] }, "san_CreditImpairmentLossesOnOtherFinancialAssetsAtAmortisedCost": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditImpairmentLossesOnOtherFinancialAssetsAtAmortisedCost", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impairment losses on other financial assets at amortised cost", "label": "Credit Impairment Losses On Other Financial Assets At Amortised Cost", "documentation": "Credit impairment losses on other financial assets at amortised cost." } } }, "auth_ref": [] }, "ifrs-full_CreditImpairmentOfFinancialInstrumentsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CreditImpairmentOfFinancialInstrumentsAxis", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Credit impairment of financial instruments [axis]", "label": "Credit impairment of financial instruments [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r131", "r137", "r237", "r243" ] }, "ifrs-full_CreditImpairmentOfFinancialInstrumentsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CreditImpairmentOfFinancialInstrumentsDomain", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Credit impairment of financial instruments [domain]", "label": "Credit impairment of financial instruments [domain]" } }, "en": { "role": { "documentation": "This member stands for all statuses of credit impairment of financial instruments. A financial instrument is credit-impaired when one or more events that have a detrimental impact on the estimated future cash flows of that financial instrument have occurred. This member also represents the standard value for the 'Credit impairment of financial instruments' axis if no other member is used." } } }, "auth_ref": [ "r131", "r137", "r237", "r243" ] }, "san_CreditLinkedNotesIssued": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditLinkedNotesIssued", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Credit linked notes", "label": "Credit Linked Notes Issued", "documentation": "Credit linked notes issued." } } }, "auth_ref": [] }, "san_CreditLinkedNotesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditLinkedNotesMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Credit linked notes", "label": "Credit Linked Notes [Member]", "documentation": "Credit linked note." } } }, "auth_ref": [] }, "san_CreditRiskAdjustmentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CreditRiskAdjustmentsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Credit risk adjustment", "label": "Credit Risk Adjustments [Member]", "documentation": "Credit risk adjustment." } } }, "auth_ref": [] }, "ifrs-full_CurrencySwapContractMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CurrencySwapContractMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Exchange rate contracts", "label": "Currency swap contract [member]" } }, "en": { "role": { "documentation": "This member stands for a currency swap contract. [Refer: Swap contract [member]]" } } }, "auth_ref": [ "r361" ] }, "san_CurrentAndDemandAccountsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CurrentAndDemandAccountsMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Demand and time deposits", "label": "Current And Demand Accounts [Member]", "documentation": "Current and demand accounts [member]" } } }, "auth_ref": [] }, "dei_CurrentFiscalYearEndDate": { "xbrltype": "gMonthDayItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "CurrentFiscalYearEndDate", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Current Fiscal Year End Date", "label": "Current Fiscal Year End Date", "documentation": "End date of current fiscal year in the format --MM-DD." } } }, "auth_ref": [] }, "ifrs-full_CurrentTaxAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CurrentTaxAssets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 6.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Current tax assets", "label": "Current tax assets" } }, "en": { "role": { "documentation": "The excess of amount paid for current tax in respect of current and prior periods over the amount due for those periods. Current tax is the amount of income taxes payable (recoverable) in respect of the taxable profit (tax loss) for a period." } } }, "auth_ref": [ "r268" ] }, "san_CustomerDepositsNet": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CustomerDepositsNet", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer deposits", "label": "Customer Deposits Net", "documentation": "The amount of net customer deposits." } } }, "auth_ref": [] }, "san_CustomerLoansNet": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CustomerLoansNet", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer loans", "label": "Customer Loans Net", "documentation": "The amount of net customer loans." } } }, "auth_ref": [] }, "san_CustomerRemediationMotorMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CustomerRemediationMotorMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer remediation - Motor", "label": "Customer Remediation - Motor [Member]", "documentation": "CusCustomer Remediation - Motor" } } }, "auth_ref": [] }, "san_CustomerRemediationOtherMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "CustomerRemediationOtherMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer remediation - other", "label": "Customer Remediation, Other [Member]", "documentation": "Other, Customer Remediation" } } }, "auth_ref": [] }, "ifrs-full_CustomerrelatedIntangibleAssetsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "CustomerrelatedIntangibleAssetsRecognisedAsOfAcquisitionDate", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer-related intangible assets recognised as of acquisition date", "label": "Customer-related intangible assets recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for customer-related intangible assets acquired in a business combination. [Refer: Customer-related intangible assets [member]; Total for all business combinations [member]]" } } }, "auth_ref": [ "r357" ] }, "ifrs-full_DatedSubordinatedLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DatedSubordinatedLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails": { "parentTag": "ifrs-full_SubordinatedLiabilities", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Dated subordinated liabilities", "label": "Dated subordinated liabilities" } }, "en": { "role": { "documentation": "The amount of subordinated liabilities that have a specified repayment date. [Refer: Subordinated liabilities]" } } }, "auth_ref": [ "r361" ] }, "san_DebitBalancesInOtherCurrentPayables": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DebitBalancesInOtherCurrentPayables", "crdr": "debit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_DepositsFromCustomers", "weight": -1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Other item, debit balances in other current payables", "label": "Debit Balances in Other Current Payables", "documentation": "Debit Balances in Other Current Payables" } } }, "auth_ref": [] }, "ifrs-full_DebtInstrumentsHeldAtAmortisedCost": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DebtInstrumentsHeldAtAmortisedCost", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Financial assets at amortised cost", "label": "Debt instruments held at amortised cost" } }, "en": { "role": { "documentation": "The amount of instruments representing indebtedness held by the entity at amortised cost. [Refer: Debt instruments held; Financial assets at amortised cost]" } } }, "auth_ref": [ "r364" ] }, "ifrs-full_DebtSecurities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DebtSecurities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 4.0 }, "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialLiabilities", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Debt securities in issue", "verboseLabel": "Debt securities", "label": "Debt instruments issued" } }, "en": { "role": { "documentation": "The amount of instruments issued by the entity that represent indebtedness." } } }, "auth_ref": [ "r364" ] }, "san_DebtSecuritiesAndOtherDebtInstrumentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DebtSecuritiesAndOtherDebtInstrumentsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Debt securities and other debt instruments", "label": "Debt Securities And Other Debt Instruments [Member]", "documentation": "Debt Securities And Other Debt Instruments" } } }, "auth_ref": [] }, "san_DebtSecuritiesInIssueAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DebtSecuritiesInIssueAbstract", "lang": { "en-us": { "role": { "terseLabel": "Debt Securities In Issue [abstract]", "label": "Debt Securities In Issue [Abstract]", "documentation": "Debt securities in issue." } } }, "auth_ref": [] }, "san_DebtSecuritiesInIssueLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DebtSecuritiesInIssueLineItems", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Debt Securities In Issue [Line Items]", "label": "Debt Securities In Issue [line items]", "documentation": "Debt securities in issue." } } }, "auth_ref": [] }, "san_DebtSecuritiesInIssueMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DebtSecuritiesInIssueMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Debt securities in issue", "label": "Debt Securities In Issue [Member]", "documentation": "Debt securities." } } }, "auth_ref": [] }, "san_DebtSecuritiesInIssueTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DebtSecuritiesInIssueTable", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Debt Securities In Issue [Table]", "label": "Debt Securities In Issue [table]", "documentation": "Debt securities in issue." } } }, "auth_ref": [] }, "ifrs-full_DebtSecuritiesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DebtSecuritiesMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Debt securities", "label": "Debt securities [member]" } }, "en": { "role": { "documentation": "This member stands for instruments held by the entity that represent indebtedness." } } }, "auth_ref": [ "r295", "r297" ] }, "san_DebtSecuritiesRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DebtSecuritiesRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Debt securities in issue", "label": "Debt Securities Recognised As Of Acquisition Date", "documentation": "Debt Securities Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_DecreaseOfOneHundredBasisPointsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DecreaseOfOneHundredBasisPointsMember", "presentation": [ "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails" ], "lang": { "en-us": { "role": { "terseLabel": "-100bps", "label": "Decrease Of One Hundred Basis Points [Member]", "documentation": "Decrease Of One Hundred Basis Points" } } }, "auth_ref": [] }, "ifrs-full_DecreaseThroughDerecognitionFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DecreaseThroughDerecognitionFinancialAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Redemptions, repayments and assets sold", "label": "Decrease through derecognition, financial assets" } }, "en": { "role": { "documentation": "The decrease in financial assets resulting from derecognition. [Refer: Financial assets]" } } }, "auth_ref": [ "r305", "r307", "r313", "r322", "r324" ] }, "ifrs-full_DecreaseThroughWriteoffFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DecreaseThroughWriteoffFinancialAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Assets written off", "label": "Decrease through write-off, financial assets" } }, "en": { "role": { "documentation": "The decrease in financial assets resulting from write-off. [Refer: Financial assets]" } } }, "auth_ref": [ "r305", "r307", "r313", "r322", "r324" ] }, "ifrs-full_DeferredTaxAssetsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DeferredTaxAssetsRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 10.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deferred tax assets", "label": "Deferred tax assets recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for deferred tax assets acquired in a business combination. [Refer: Deferred tax assets; Total for all business combinations [member]]" } } }, "auth_ref": [ "r357" ] }, "ifrs-full_DeferredTaxLiabilitiesRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DeferredTaxLiabilitiesRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 8.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deferred tax liabilities", "label": "Deferred tax liabilities recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for deferred tax liabilities assumed in a business combination. [Refer: Deferred tax liabilities; Total for all business combinations [member]]" } } }, "auth_ref": [ "r357" ] }, "ifrs-full_DefinedBenefitObligationAtPresentValue": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DefinedBenefitObligationAtPresentValue", "crdr": "credit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofNetAssetsRecognisedDetails": { "parentTag": "ifrs-full_LiabilityAssetOfDefinedBenefitPlans", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofNetAssetsRecognisedDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Present value of defined benefit obligations", "label": "Defined benefit obligation, at present value" } }, "en": { "role": { "documentation": "The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]" } } }, "auth_ref": [ "r345" ] }, "ifrs-full_DefinedBenefitPlansAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DefinedBenefitPlansAxis", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Defined benefit plans [axis]", "label": "Defined benefit plans [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r12", "r189" ] }, "ifrs-full_DefinedBenefitPlansDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DefinedBenefitPlansDomain", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Defined benefit plans [domain]", "label": "Defined benefit plans [domain]" } }, "en": { "role": { "documentation": "This member stands for post-employment benefit plans other than defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods. It also represents the standard value for the 'Defined benefit plans' axis if no other member is used." } } }, "auth_ref": [ "r12", "r189" ] }, "san_DepositsByBanksMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsByBanksMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits by banks", "label": "Deposits By Banks [Member]", "documentation": "Deposits by banks." } } }, "auth_ref": [] }, "san_DepositsByCustomersMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsByCustomersMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits by customers", "label": "Deposits By Customers [Member]", "documentation": "Deposits by customers." } } }, "auth_ref": [] }, "ifrs-full_DepositsFromBanks": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DepositsFromBanks", "crdr": "credit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialLiabilities", "weight": 1.0, "order": 5.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 12.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/DEPOSITSBYBANKSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits by banks", "label": "Deposits from banks" } }, "en": { "role": { "documentation": "The amount of deposit liabilities from banks held by the entity." } } }, "auth_ref": [ "r364" ] }, "san_DepositsFromBanksRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsFromBanksRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits by banks", "label": "Deposits From Banks Recognised As Of Acquisition Date", "documentation": "Deposits From Banks Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_DepositsFromBanksSettlementActivities": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsFromBanksSettlementActivities", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits from banks, settlement activities", "label": "Deposits From Banks, Settlement Activities", "documentation": "Deposits From Banks, Settlement Activities" } } }, "auth_ref": [] }, "ifrs-full_DepositsFromCustomers": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DepositsFromCustomers", "crdr": "credit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialLiabilities", "weight": 1.0, "order": 3.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 9.0 }, "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits by customers", "totalLabel": "Deposits by customers", "label": "Deposits from customers" } }, "en": { "role": { "documentation": "The amount of deposit liabilities from customers held by the entity." } } }, "auth_ref": [ "r364" ] }, "ifrs-full_DepositsFromCustomersAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DepositsFromCustomersAbstract", "lang": { "en-us": { "role": { "terseLabel": "Deposits from customers [abstract]", "label": "Deposits from customers [abstract]" } } }, "auth_ref": [] }, "san_DepositsFromCustomersGross": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsFromCustomersGross", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer balances (gross)", "label": "Deposits From Customers, Gross", "documentation": "Deposits From Customers, Gross" } } }, "auth_ref": [] }, "san_DepositsFromCustomersNet": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsFromCustomersNet", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_DepositsFromCustomers", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer balances (net)", "label": "Deposits From Customers, Net", "documentation": "Deposits From Customers, Net" } } }, "auth_ref": [] }, "san_DepositsFromCustomersRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsFromCustomersRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits by customers", "label": "Deposits From Customers Recognised As Of Acquisition Date", "documentation": "Deposits From Customers Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_DepositsHeldAsCollateralMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DepositsHeldAsCollateralMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Deposits held as collateral", "label": "Deposits Held As Collateral [member]", "documentation": "Deposits Held As Collateral [Member]" } } }, "auth_ref": [] }, "ifrs-full_DepreciationAmortisationAndImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DepreciationAmortisationAndImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss", "crdr": "debit", "calculation": { "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails": { "parentTag": "san_OperatingExpensesBeforeCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Depreciation, amortisation and impairment", "label": "Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss" } } }, "auth_ref": [ "r361" ] }, "ifrs-full_DepreciationPropertyPlantAndEquipmentIncludingRightofuseAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DepreciationPropertyPlantAndEquipmentIncludingRightofuseAssets", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Charge for the period", "label": "Depreciation, property, plant and equipment including right-of-use assets" } } }, "auth_ref": [ "r339" ] }, "san_DerivativeAssetsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativeAssetsMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative assets", "label": "Derivative Assets [member]", "documentation": "Derivative assets for financial assets." } } }, "auth_ref": [] }, "ifrs-full_DerivativeFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DerivativeFinancialAssets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 15.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative financial instruments", "verboseLabel": "Assets", "label": "Derivative financial assets" } }, "en": { "role": { "documentation": "The amount of financial assets classified as derivative instruments. [Refer: Financial assets; Derivatives [member]]" } } }, "auth_ref": [ "r364" ] }, "san_DerivativeFinancialInstrumentRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativeFinancialInstrumentRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative financial instruments", "label": "Derivative Financial Instrument Recognised As Of Acquisition Date", "documentation": "Derivative Financial Instrument Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_DerivativeFinancialInstrumentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativeFinancialInstrumentsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Derivative financial instruments", "label": "Derivative Financial Instruments [Member]", "documentation": "bc51539f-bbe6-8f2b-ee4e-bbaef1cf9127" } } }, "auth_ref": [] }, "ifrs-full_DerivativeFinancialLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DerivativeFinancialLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 11.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative financial instruments", "verboseLabel": "Liabilities", "label": "Derivative financial liabilities" } }, "en": { "role": { "documentation": "The amount of financial liabilities classified as derivative instruments. [Refer: Financial assets; Derivatives [member]]" } } }, "auth_ref": [ "r364" ] }, "san_DerivativeFinancialLiabilitiesRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativeFinancialLiabilitiesRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative financial instruments", "label": "Derivative Financial Liabilities Recognised As Of Acquisition Date", "documentation": "Derivative Financial Liabilities Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_DerivativeInstrumentsAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativeInstrumentsAxis", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative Instruments [Axis]", "label": "Derivative Instruments [Axis]", "documentation": "Derivative Instruments" } } }, "auth_ref": [] }, "san_DerivativeInstrumentsDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativeInstrumentsDomain", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative Instruments [Domain]", "label": "Derivative Instruments [Domain]", "documentation": "Derivative Instruments [Domain]" } } }, "auth_ref": [] }, "san_DerivativeLiabilitiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativeLiabilitiesMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative liabilities", "verboseLabel": "Derivatives", "label": "Derivative Liabilities [Member]", "documentation": "Derivative liabilities for financial liabilities." } } }, "auth_ref": [] }, "san_DerivativesHeldForHedgingMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativesHeldForHedgingMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivatives held for hedging", "label": "Derivatives Held For Hedging [Member]", "documentation": "Derivatives Held For Hedging [member]" } } }, "auth_ref": [] }, "san_DerivativesHeldForTradingMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DerivativesHeldForTradingMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivatives held for trading:", "label": "Derivatives Held For Trading [Member]", "documentation": "Derivatives Held For Hedging [Member]" } } }, "auth_ref": [] }, "ifrs-full_DerivativesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DerivativesMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivatives", "label": "Derivatives [member]" } }, "en": { "role": { "documentation": "This member stands for financial instruments or other contracts within the scope of IFRS 9 with all three of the following characteristics: (a) Their value changes in response to the change in a specified interest rate, financial instrument price, commodity price, foreign exchange rate, index of prices or rates, credit rating or credit index, or other variable, provided in the case of a non-financial variable that the variable is not specific to a party to the contract (sometimes called the \u2018underlying\u2019); (b) They require no initial net investment or an initial net investment that is smaller than would be required for other types of contracts that would be expected to have a similar response to changes in market factors; (c) They are settled at a future date. [Refer: Classes of financial instruments [domain]]" } } }, "auth_ref": [ "r295", "r297", "r311", "r314" ] }, "ifrs-full_DescriptionOfChangesInMethodsAndAssumptionsUsedInPreparingSensitivityAnalysisForActuarialAssumptions": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DescriptionOfChangesInMethodsAndAssumptionsUsedInPreparingSensitivityAnalysisForActuarialAssumptions", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Description of changes in methods and assumptions", "label": "Description of changes in methods and assumptions used in preparing sensitivity analysis for actuarial assumptions" } }, "en": { "role": { "documentation": "The description of changes in the methods and assumptions used in preparing a sensitivity analysis for significant actuarial assumptions. [Refer: Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r20" ] }, "ifrs-full_DescriptionOfVoluntaryChangeInAccountingPolicy": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DescriptionOfVoluntaryChangeInAccountingPolicy", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of Voluntary change in Accounting Policy", "label": "Disclosure of voluntary change in accounting policy [text block]" } }, "en": { "role": { "documentation": "The disclosure of a voluntary change in accounting policy." } } }, "auth_ref": [ "r68", "r178" ] }, "san_DetailedDisclosureOfRepurchaseAgreementsNonTradingTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DetailedDisclosureOfRepurchaseAgreementsNonTradingTableTextBlock", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGTables" ], "lang": { "en-us": { "role": { "terseLabel": "Repurchase Agreements - Non Trading", "label": "Detailed Disclosure Of Repurchase Agreements Non-Trading [Table Text Block]", "documentation": "Detailed disclosure of repurchase agreements non-trading." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfAccountingJudgementsAndEstimatesExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfAccountingJudgementsAndEstimatesExplanatory", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESPolicies" ], "lang": { "en-us": { "role": { "terseLabel": "Critical judgements and accounting estimates", "label": "Disclosure of accounting judgements and estimates [text block]" } }, "en": { "role": { "documentation": "The disclosure of judgements that management has made in the process of applying the entity's accounting policies that have the most significant effect on amounts recognised in the financial statements along with information about the assumptions that the entity makes about the future, and other major sources of estimation uncertainty at the end of the reporting period, that have a significant risk of resulting in a material adjustment to the carrying amounts of assets and liabilities within the next year. [Refer: Carrying amount [member]]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfAmountsRecognisedInOtherComprehensiveIncomeTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfAmountsRecognisedInOtherComprehensiveIncomeTableTextBlock", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Amounts Recognised in Other Comprehensive Income", "label": "Disclosure Of Amounts Recognised In Other Comprehensive Income [Table Text Block]", "documentation": "Disclosure of amounts recognised in Other Comprehensive Income." } } }, "auth_ref": [] }, "san_DisclosureOfAnalysisOfSecuritisationsAndCoveredBondsTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfAnalysisOfSecuritisationsAndCoveredBondsTableTextBlock", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of Analysis of Securitisations and Covered Bonds", "label": "Disclosure Of Analysis Of Securitisations And Covered Bonds [Table Text Block]", "documentation": "Disclosure of analysis of securitisations and covered bonds." } } }, "auth_ref": [] }, "san_DisclosureOfAssetsPledgedAsSecurityAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfAssetsPledgedAsSecurityAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of assets pledged as security [abstract]", "label": "Disclosure Of Assets Pledged As Security [Abstract]", "documentation": "Disclosure of assets pledged as security." } } }, "auth_ref": [] }, "san_DisclosureOfAssetsPledgedAsSecurityLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfAssetsPledgedAsSecurityLineItems", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Assets Pledged As Security [Line Items]", "label": "Disclosure Of Assets Pledged As Security [Line Items]", "documentation": "Disclosure of assets pledged as security." } } }, "auth_ref": [] }, "san_DisclosureOfAssetsPledgedAsSecurityTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfAssetsPledgedAsSecurityTable", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Assets Pledged As Security [Table]", "label": "Disclosure Of Assets Pledged As Security [Table]", "documentation": "Disclosure of assets pledged as security [table]" } } }, "auth_ref": [] }, "san_DisclosureOfBaseExpectedCreditLossesToProbabilityWeightedEstimatedCreditLossesTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfBaseExpectedCreditLossesToProbabilityWeightedEstimatedCreditLossesTableTextBlock", "presentation": [ "http://santander.co.uk/role/CreditRiskTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of Base Expected Credit Losses to Probability Weighted Estimated Credit Losses", "label": "Disclosure Of Base Expected Credit Losses To Probability Weighted Estimated Credit Losses [Table Text Block]", "documentation": "The disclosure of base expected credit losses to probability weighted estimated credit losses." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfBasisOfPreparationOfFinancialStatementsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfBasisOfPreparationOfFinancialStatementsExplanatory", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESPolicies" ], "lang": { "en-us": { "role": { "verboseLabel": "Basis of preparation and accounting developments", "label": "Disclosure of basis of preparation of financial statements [text block]" } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfBusinessCombinationsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfBusinessCombinationsExplanatory", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSB" ], "lang": { "en-us": { "role": { "terseLabel": "ACQUISITION OF TSB", "label": "Disclosure of business combinations [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for business combinations." } } }, "auth_ref": [ "r118" ] }, "ifrs-full_DisclosureOfBusinessCombinationsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfBusinessCombinationsLineItems", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about business combination [line items]", "label": "Disclosure of detailed information about business combination [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfBusinessCombinationsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfBusinessCombinationsTable", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about business combination [table]", "label": "Disclosure of detailed information about business combination [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to details of business combinations." } } }, "auth_ref": [ "r114", "r220" ] }, "san_DisclosureOfCapitalRiskExposureAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfCapitalRiskExposureAbstract", "lang": { "en-us": { "role": { "label": "Disclosure Of Capital Risk Exposure [Abstract]", "documentation": "Capital risk." } } }, "auth_ref": [] }, "san_DisclosureOfCapitalRiskTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfCapitalRiskTextBlock", "presentation": [ "http://santander.co.uk/role/CapitalRisk" ], "lang": { "en-us": { "role": { "terseLabel": "Capital Risk", "label": "Disclosure Of Capital Risk [Text Block]", "documentation": "The disclosure of capital risk." } } }, "auth_ref": [] }, "san_DisclosureOfCashFlowFromAcquisitionTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfCashFlowFromAcquisitionTableTextBlock", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of cash flow from acquisition", "label": "Disclosure Of Cash Flow From Acquisition [Table Text Block]", "documentation": "Disclosure Of Cash Flow From Acquisition" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfChangesInAccountingEstimatesLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfChangesInAccountingEstimatesLineItems", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/ACCOUNTINGPOLICIESCriticaljudgementsandaccountingestimatesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of changes in accounting estimates [line items]", "label": "Disclosure of changes in accounting estimates [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfChangesInAccountingEstimatesTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfChangesInAccountingEstimatesTable", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/ACCOUNTINGPOLICIESCriticaljudgementsandaccountingestimatesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of changes in accounting estimates [table]", "label": "Disclosure of changes in accounting estimates [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to the changes in accounting estimates." } } }, "auth_ref": [ "r69", "r179" ] }, "ifrs-full_DisclosureOfChangesInAccountingPoliciesExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfChangesInAccountingPoliciesExplanatory", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESPolicies" ], "lang": { "en-us": { "role": { "terseLabel": "Change in accounting policy", "label": "Disclosure of changes in accounting policies [text block]" } }, "en": { "role": { "documentation": "The disclosure of changes made to accounting policies by the entity." } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfClassesOfShareCapitalAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfClassesOfShareCapitalAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of classes of share capital [abstract]", "label": "Disclosure of classes of share capital [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfCollateralExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfCollateralExplanatory", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETS" ], "lang": { "en-us": { "role": { "terseLabel": "ASSETS CHARGED AS SECURITY FOR LIABILITIES AND COLLATERAL ACCEPTED AS SECURITY FOR ASSETS", "label": "Disclosure of collateral [text block]" } }, "en": { "role": { "documentation": "The disclosure of assets and liabilities used as collateral." } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTS" ], "lang": { "en-us": { "role": { "terseLabel": "CONTINGENT LIABILITIES AND COMMITMENTS", "label": "Disclosure of commitments and contingent liabilities [text block]" } }, "en": { "role": { "documentation": "The disclosure of commitments and contingent liabilities. [Refer: Classes of contingent liabilities [domain]]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfCommitmentsContingentLiabilitiesAndGuaranteesTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfCommitmentsContingentLiabilitiesAndGuaranteesTableTextBlock", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Contingent Liabilities and Commitments", "label": "Disclosure Of Commitments Contingent Liabilities And Guarantees [Table Text Block]", "documentation": "The disclosure of commitments contingent liabilities and guarantees." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfContingentLiabilitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfContingentLiabilitiesAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of contingent liabilities [abstract]", "label": "Disclosure of contingent liabilities [abstract]" } } }, "auth_ref": [] }, "san_DisclosureOfContingentLiabilitiesAndCommitmentsLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfContingentLiabilitiesAndCommitmentsLineItems", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Contingent Liabilities And Commitments [Line Items]", "label": "Disclosure Of Contingent Liabilities And Commitments [Line Items]", "documentation": "Disclosure of contingent liabilities and commitments." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfContingentLiabilitiesLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfContingentLiabilitiesLineItems", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of contingent liabilities [line items]", "label": "Disclosure of contingent liabilities [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfContingentLiabilitiesTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfContingentLiabilitiesTable", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of contingent liabilities [table]", "label": "Disclosure of contingent liabilities [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to contingent liabilities." } } }, "auth_ref": [ "r42", "r206" ] }, "san_DisclosureOfCreditImpairmentLossAndProvisionsAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfCreditImpairmentLossAndProvisionsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of credit impairment loss and provisions [abstract]", "label": "Disclosure Of Credit Impairment Loss And Provisions [Abstract]", "documentation": "Disclosure of credit impairment loss and provisions." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfCreditRiskExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfCreditRiskExplanatory", "presentation": [ "http://santander.co.uk/role/CreditRisk" ], "lang": { "en-us": { "role": { "terseLabel": "Credit Risk", "label": "Disclosure of credit risk [text block]" } }, "en": { "role": { "documentation": "The disclosure of credit risk. [Refer: Credit risk [member]]" } } }, "auth_ref": [ "r149", "r359" ] }, "ifrs-full_DisclosureOfCreditRiskExposureAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfCreditRiskExposureAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of credit risk exposure [abstract]", "label": "Disclosure of credit risk exposure [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfCreditRiskExposureLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfCreditRiskExposureLineItems", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of credit risk exposure [line items]", "label": "Disclosure of credit risk exposure [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfCreditRiskExposureTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfCreditRiskExposureTable", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of credit risk exposure [table]", "label": "Disclosure of credit risk exposure [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to the credit risk exposure." } } }, "auth_ref": [ "r137", "r243" ] }, "ifrs-full_DisclosureOfDebtSecuritiesExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfDebtSecuritiesExplanatory", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUE" ], "lang": { "en-us": { "role": { "terseLabel": "DEBT SECURITIES IN ISSUE", "label": "Disclosure of debt instruments [text block]" } }, "en": { "role": { "documentation": "The disclosure of debt instruments. [Refer: Debt instruments issued; Debt instruments held]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfDebtSecuritiesInIssueTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDebtSecuritiesInIssueTableTextBlock", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUETables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Debt Securities in Issue", "label": "Disclosure Of Debt Securities In Issue [Table Text Block]", "documentation": "Disclosure of debt securities in issue." } } }, "auth_ref": [] }, "san_DisclosureOfDefinedBenefitPlanActuarialAssumptionsTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDefinedBenefitPlanActuarialAssumptionsTableTextBlock", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Principal Actuarial Assumptions Used for Defined Benefit Schemes", "label": "Disclosure Of Defined Benefit Plan Actuarial Assumptions [Table Text Block]", "documentation": "Disclosure Of Defined Benefit Plan Actuarial Assumptions" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfDefinedBenefitPlansExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfDefinedBenefitPlansExplanatory", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Retirement Benefit Plans", "label": "Disclosure of defined benefit plans [text block]" } }, "en": { "role": { "documentation": "The disclosure of defined benefit plans. [Refer: Defined benefit plans [domain]]" } } }, "auth_ref": [ "r12", "r189" ] }, "san_DisclosureOfDepositsByBankTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDepositsByBankTableTextBlock", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Schedule of Deposits by Banks", "label": "Disclosure Of Deposits By Bank [Table Text Block]", "documentation": "Disclosure of deposits by bank." } } }, "auth_ref": [] }, "san_DisclosureOfDepositsFromBanksAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDepositsFromBanksAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of deposits from banks [abstract]", "label": "Disclosure Of Deposits From Banks [Abstract]", "documentation": "Disclosure of deposits from banks." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfDepositsFromBanksExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfDepositsFromBanksExplanatory", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKS" ], "lang": { "en-us": { "role": { "terseLabel": "DEPOSITS BY BANKS", "label": "Disclosure of deposits from banks [text block]" } }, "en": { "role": { "documentation": "The disclosure of deposits from banks. [Refer: Deposits from banks]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfDepositsFromBanksLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDepositsFromBanksLineItems", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Deposits From Banks [Line Items]", "label": "Disclosure Of Deposits From Banks [Line Items]", "documentation": "Line Items represents disclosure of deposits from banks." } } }, "auth_ref": [] }, "san_DisclosureOfDepositsFromBanksTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDepositsFromBanksTable", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Deposits From Banks [Table]", "label": "Disclosure Of Deposits From Banks [table]", "documentation": "Disclosure Of Deposits From Banks [table]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfDepositsFromCustomersExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfDepositsFromCustomersExplanatory", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERS" ], "lang": { "en-us": { "role": { "terseLabel": "DEPOSITS BY CUSTOMERS", "label": "Disclosure of deposits from customers [text block]" } }, "en": { "role": { "documentation": "The disclosure of deposits from customers. [Refer: Deposits from customers]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfDepositsFromCustomersLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDepositsFromCustomersLineItems", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails", "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Deposits From Customers [Line Items]", "label": "Disclosure Of Deposits From Customers [Line Items]", "documentation": "Disclosure of deposits from customers." } } }, "auth_ref": [] }, "san_DisclosureOfDepositsFromCustomersTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDepositsFromCustomersTable", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails", "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Deposits From Customers [Table]", "label": "Disclosure Of Deposits From Customers [Table]", "documentation": "Disclosure of deposits from customers [table]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfDerivativeFinancialInstrumentsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfDerivativeFinancialInstrumentsExplanatory", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTS" ], "lang": { "en-us": { "role": { "terseLabel": "DERIVATIVE FINANCIAL INSTRUMENTS", "label": "Disclosure of derivative financial instruments [text block]" } }, "en": { "role": { "documentation": "The disclosure of derivative financial instruments. [Refer: Derivatives [member]]" } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about business combination [text block]", "label": "Disclosure of detailed information about business combination [text block]" } }, "en": { "role": { "documentation": "The disclosure of detailed information about business combinations. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r119" ] }, "san_DisclosureOfDetailedInformationAboutDepositsFromCustomersTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDetailedInformationAboutDepositsFromCustomersTableTextBlock", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Schedule of Deposits by Customers", "label": "Disclosure Of Detailed Information About Deposits From Customers [Table Text Block]", "documentation": "Disclosure of detailed information about deposits from customers." } } }, "auth_ref": [] }, "san_DisclosureOfDetailedInformationOfImpairmentChargesAndProvisionsTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDetailedInformationOfImpairmentChargesAndProvisionsTableTextBlock", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESANDPROVISIONSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Impairment Losses and Provisions", "label": "Disclosure Of Detailed Information Of Impairment Charges And Provisions [Table Text Block]", "documentation": "The disclosure of impairment loss, the reversal of impairment loss and provisions." } } }, "auth_ref": [] }, "san_DisclosureOfDetailedInformationOfOtherFinancialAssetsAtAmortisedCostTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDetailedInformationOfOtherFinancialAssetsAtAmortisedCostTableTextBlock", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Other Financial Assets at Amortised Cost", "label": "Disclosure Of Detailed Information Of Other Financial Assets At Amortised Cost [Table Text Block]", "documentation": "Disclosure of detailed information of other financial assets at amortised cost explanatory." } } }, "auth_ref": [] }, "san_DisclosureOfDetailsOfSubordinatedLiabilitiesTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfDetailsOfSubordinatedLiabilitiesTableTextBlock", "presentation": [ "http://santander.co.uk/role/SUBORDINATEDLIABILITIESTables" ], "lang": { "en-us": { "role": { "terseLabel": "Schedule of Subordinated Liabilities", "label": "Disclosure Of Details Of Subordinated Liabilities [Table Text Block]", "documentation": "Schedule of subordinated liabilities." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfDividendsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfDividendsExplanatory", "presentation": [ "http://santander.co.uk/role/DIVIDENDSONORDINARYSHARES" ], "lang": { "en-us": { "role": { "terseLabel": "DIVIDENDS ON ORDINARY SHARES", "label": "Disclosure of dividends [text block]" } }, "en": { "role": { "documentation": "The disclosure of dividends. Dividends are distributions of profits to holders of equity investments in proportion to their holdings of a particular class of capital." } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfEmployeeBenefitsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfEmployeeBenefitsExplanatory", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANS" ], "lang": { "en-us": { "role": { "terseLabel": "RETIREMENT BENEFIT PLANS", "label": "Disclosure of employee benefits [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for employee benefits." } } }, "auth_ref": [ "r23" ] }, "ifrs-full_DisclosureOfEntitysReportableSegmentsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfEntitysReportableSegmentsExplanatory", "presentation": [ "http://santander.co.uk/role/SEGMENTS" ], "lang": { "en-us": { "role": { "terseLabel": "SEGMENTS", "label": "Disclosure of entity's operating segments [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for operating segments." } } }, "auth_ref": [ "r160" ] }, "ifrs-full_DisclosureOfEventsAfterReportingPeriodExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfEventsAfterReportingPeriodExplanatory", "presentation": [ "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATE" ], "lang": { "en-us": { "role": { "terseLabel": "EVENTS AFTER THE BALANCE SHEET DATE", "label": "Disclosure of events after reporting period [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for events after the reporting period." } } }, "auth_ref": [ "r1" ] }, "ifrs-full_DisclosureOfExpensesExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfExpensesExplanatory", "presentation": [ "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONS" ], "lang": { "en-us": { "role": { "terseLabel": "OPERATING EXPENSES BEFORE CREDIT IMPAIRMENT CHARGES, RESTRUCTURING AND SPECIFIC PROVISIONS", "label": "Disclosure of expenses [text block]" } }, "en": { "role": { "documentation": "The disclosure of expenses." } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfFairValueMeasurementOfAssetsAndLiabilitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfFairValueMeasurementOfAssetsAndLiabilitiesAbstract", "lang": { "en-us": { "role": { "label": "Disclosure Of Fair Value Measurement Of Assets And Liabilities [Abstract]", "documentation": "Disclosure Of Fair Value Measurement Of Assets And Liabilities" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfFairValueMeasurementOfAssetsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFairValueMeasurementOfAssetsLineItems", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of fair value measurement of assets [line items]", "label": "Disclosure of fair value measurement of assets [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfFairValueMeasurementOfAssetsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFairValueMeasurementOfAssetsTable", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of fair value measurement of assets [table]", "label": "Disclosure of fair value measurement of assets [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to the fair value measurement of assets." } } }, "auth_ref": [ "r93", "r249" ] }, "san_DisclosureOfFairValueMeasurementsOfAssetsAndLiabilitiesLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfFairValueMeasurementsOfAssetsAndLiabilitiesLineItems", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Fair Value Measurements Of Assets And Liabilities [Line Items]", "label": "Disclosure Of Fair Value Measurements Of Assets And Liabilities [Line Items]", "documentation": "Disclosure of fair value measurements of assets and liabilities." } } }, "auth_ref": [] }, "san_DisclosureOfFairValueOfFinancialInstrumentsAtAmortisedCostTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfFairValueOfFinancialInstrumentsAtAmortisedCostTableTextBlock", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of Analysis of Fair Value of Financial Instruments Carried at Amortised Cost", "label": "Disclosure Of Fair Value Of Financial Instruments At Amortised Cost [Table Text Block]", "documentation": "Disclosure of fair value of financial instruments at amortised cost." } } }, "auth_ref": [] }, "san_DisclosureOfFairValueOfFinancialInstrumentsAtFairValueTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfFairValueOfFinancialInstrumentsAtFairValueTableTextBlock", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of Analysis of Fair Value of Financial Instruments Measured at Fair Value on a Recurring Basis", "label": "Disclosure Of Fair Value Of Financial Instruments At Fair Value [Table Text Block]", "documentation": "Disclosure of fair value of financial instruments at fair value." } } }, "auth_ref": [] }, "san_DisclosureOfFairValuesOfFinancialInstrumentsCarriedAtAmortisedCostLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfFairValuesOfFinancialInstrumentsCarriedAtAmortisedCostLineItems", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Fair Values Of Financial Instruments Carried At Amortised Cost [Line Items]", "label": "Disclosure Of Fair Values Of Financial Instruments Carried At Amortised Cost [Line Items]", "documentation": "Disclosure Of Fair Values Of Financial Instruments Carried At Amortised Cost [line items]" } } }, "auth_ref": [] }, "san_DisclosureOfFairValuesOfFinancialInstrumentsCarriedAtAmortisedCostTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfFairValuesOfFinancialInstrumentsCarriedAtAmortisedCostTable", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Fair Values Of Financial Instruments Carried At Amortised Cost [Table]", "label": "Disclosure Of Fair Values Of Financial Instruments Carried At Amortised Cost [table]", "documentation": "Disclosure Of Fair Values Of Financial Instruments Carried At Amortised Cost [table]" } } }, "auth_ref": [] }, "san_DisclosureOfFinancialAssetsDesignatedAsMeasuredAtFairValueThroughProfitOrLossTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfFinancialAssetsDesignatedAsMeasuredAtFairValueThroughProfitOrLossTable", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Financial Assets Designated As Measured At Fair Value Through Profit Or Loss [Table]", "label": "Disclosure Of Financial Assets Designated As Measured At Fair Value Through Profit Or Loss [Table]", "documentation": "Disclosure Of Financial Assets Designated As Measured At Fair Value Through Profit Or Loss" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfFinancialAssetsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFinancialAssetsLineItems", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of financial assets [line items]", "label": "Disclosure of financial assets [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfFinancialAssetsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFinancialAssetsTable", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of financial assets [table]", "label": "Disclosure of financial assets [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to financial assets." } } }, "auth_ref": [ "r141", "r222" ] }, "ifrs-full_DisclosureOfFinancialInstrumentsAtFairValueThroughProfitOrLossExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFinancialInstrumentsAtFairValueThroughProfitOrLossExplanatory", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSS" ], "lang": { "en-us": { "role": { "terseLabel": "OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS", "label": "Disclosure of financial instruments at fair value through profit or loss [text block]" } }, "en": { "role": { "documentation": "The disclosure of financial instruments measured at fair value through profit or loss. [Refer: At fair value [member]; Classes of financial instruments [domain]]" } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfFinancialInstrumentsDesignatedAtFairValueThroughProfitOrLossExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFinancialInstrumentsDesignatedAtFairValueThroughProfitOrLossExplanatory", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Other Financial Assets at Fair Value Through Profit or Loss", "label": "Disclosure of financial instruments designated at fair value through profit or loss [text block]" } }, "en": { "role": { "documentation": "The disclosure of financial instruments designated at fair value through profit or loss. [Refer: At fair value [member]; Classes of financial instruments [domain]]" } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfFinancialInstrumentsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFinancialInstrumentsExplanatory", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTS" ], "lang": { "en-us": { "role": { "terseLabel": "FINANCIAL INSTRUMENTS", "label": "Disclosure of financial instruments [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for financial instruments." } } }, "auth_ref": [ "r150" ] }, "ifrs-full_DisclosureOfFinancialLiabilitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfFinancialLiabilitiesAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of financial liabilities [abstract]", "label": "Disclosure of financial liabilities [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfGoingConcernExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfGoingConcernExplanatory", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESPolicies" ], "lang": { "en-us": { "role": { "terseLabel": "Going concern", "label": "Disclosure of going concern [text block]" } }, "en": { "role": { "documentation": "The disclosure of the entity's ability to continue as a going concern." } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfHedgeAccountingLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfHedgeAccountingLineItems", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about hedges", "label": "Disclosure of detailed information about hedges [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfHedgeAccountingTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfHedgeAccountingTable", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about hedges [table]", "label": "Disclosure of detailed information about hedges [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to details of hedges." } } }, "auth_ref": [ "r253" ] }, "san_DisclosureOfImpairmentChargesOnFinancialAssetsExplanatoryTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfImpairmentChargesOnFinancialAssetsExplanatoryTextBlock", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGES" ], "lang": { "en-us": { "role": { "terseLabel": "CREDIT IMPAIRMENT CHARGES", "label": "Disclosure Of Impairment Charges On Financial Assets Explanatory [Text Block]", "documentation": "Disclosure Of Impairment Charges On Financial Assets Explanatory" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfImpairmentLossAndReversalOfImpairmentLossLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfImpairmentLossAndReversalOfImpairmentLossLineItems", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of impairment loss and reversal of impairment loss [line items]", "label": "Disclosure of impairment loss and reversal of impairment loss [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfImpairmentLossAndReversalOfImpairmentLossTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfImpairmentLossAndReversalOfImpairmentLossTable", "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of impairment loss and reversal of impairment loss [table]", "label": "Disclosure of impairment loss and reversal of impairment loss [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to impairment loss and the reversal of impairment loss." } } }, "auth_ref": [ "r31", "r197" ] }, "ifrs-full_DisclosureOfIncomeTaxExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfIncomeTaxExplanatory", "presentation": [ "http://santander.co.uk/role/TAXATION" ], "lang": { "en-us": { "role": { "terseLabel": "TAXATION", "label": "Disclosure of income tax [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for income taxes." } } }, "auth_ref": [ "r6" ] }, "san_DisclosureOfInformationAboutKeyJudgementsAndKeyEstimatesTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfInformationAboutKeyJudgementsAndKeyEstimatesTableTextBlock", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of Information about Key Judgements and Key Estimates", "label": "Disclosure Of Information About Key Judgements And Key Estimates [Table Text Block]", "documentation": "Disclosure Of Information About Key Judgements And Key Estimates" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfIntangibleAssetsAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfIntangibleAssetsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about intangible assets [abstract]", "label": "Disclosure of detailed information about intangible assets [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfIntangibleAssetsAndGoodwillExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfIntangibleAssetsAndGoodwillExplanatory", "presentation": [ "http://santander.co.uk/role/INTANGIBLEASSETS" ], "lang": { "en-us": { "role": { "terseLabel": "INTANGIBLE ASSETS", "label": "Disclosure of intangible assets and goodwill [text block]" } }, "en": { "role": { "documentation": "The disclosure of intangible assets and goodwill. [Refer: Intangible assets and goodwill]" } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfIntangibleAssetsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfIntangibleAssetsLineItems", "presentation": [ "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about intangible assets [line items]", "label": "Disclosure of detailed information about intangible assets [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfIntangibleAssetsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfIntangibleAssetsTable", "presentation": [ "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about intangible assets [table]", "label": "Disclosure of detailed information about intangible assets [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to details of intangible assets." } } }, "auth_ref": [ "r47", "r210" ] }, "ifrs-full_DisclosureOfInterestsInOtherEntitiesExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfInterestsInOtherEntitiesExplanatory", "presentation": [ "http://santander.co.uk/role/INTERESTSINOTHERENTITIES" ], "lang": { "en-us": { "role": { "terseLabel": "INTERESTS IN OTHER ENTITIES", "label": "Disclosure of interests in other entities [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for interests in other entities." } } }, "auth_ref": [ "r75" ] }, "san_DisclosureOfIssuancesAndRedemptionsOfSecuritisationAndCoveredBondProgrammesTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfIssuancesAndRedemptionsOfSecuritisationAndCoveredBondProgrammesTableTextBlock", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Issuances and Redemptions of Securitisation and Covered Bond Programme", "label": "Disclosure Of Issuances And Redemptions Of Securitisation And Covered Bond Programmes [Table Text Block]", "documentation": "Disclosure of issuances and redemptions of securitisation and covered bond programmes." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfLoansAndAdvancesToCustomersExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfLoansAndAdvancesToCustomersExplanatory", "presentation": [ "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERS" ], "lang": { "en-us": { "role": { "terseLabel": "LOANS AND ADVANCES TO CUSTOMERS", "label": "Disclosure of loans and advances to customers [text block]" } }, "en": { "role": { "documentation": "The disclosure of loans and advances to customers. [Refer: Loans and advances to customers]" } } }, "auth_ref": [ "r359" ] }, "ifrs-full_DisclosureOfMarketRiskExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfMarketRiskExplanatory", "presentation": [ "http://santander.co.uk/role/MarketRisk" ], "lang": { "en-us": { "role": { "terseLabel": "Market Risk", "label": "Disclosure of market risk [text block]" } }, "en": { "role": { "documentation": "The disclosure of market risk. [Refer: Market risk [member]]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfMarketRiskExposureAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfMarketRiskExposureAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Market Risk Exposure [Abstract]", "label": "Disclosure Of Market Risk Exposure [Abstract]", "documentation": "Disclosure Of Market Risk Exposure" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfMaterialAccountingPolicyInformationExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfMaterialAccountingPolicyInformationExplanatory", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIES" ], "lang": { "en-us": { "role": { "terseLabel": "ACCOUNTING POLICIES", "label": "Disclosure of material accounting policy information [text block]" } }, "en": { "role": { "documentation": "The entire disclosure of material accounting policy information applied by the entity." } } }, "auth_ref": [ "r174", "r251", "r263" ] }, "san_DisclosureOfNIIAndEveSensitivityOfInterestRateRiskTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfNIIAndEveSensitivityOfInterestRateRiskTableTextBlock", "presentation": [ "http://santander.co.uk/role/MarketRiskTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of NII and EVE Sensitivity of Interest Rate Risk", "label": "Disclosure Of NII And Eve Sensitivity Of Interest Rate Risk [Table Text Block]", "documentation": "The disclosure of NIM and EVE sensitivity of interest rate risk." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfNatureAndExtentOfRisksArisingFromFinancialInstrumentsAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNatureAndExtentOfRisksArisingFromFinancialInstrumentsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of nature and extent of risks arising from financial instruments [abstract]", "label": "Disclosure of nature and extent of risks arising from financial instruments [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfNetDefinedBenefitLiabilityAssetAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNetDefinedBenefitLiabilityAssetAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of net defined benefit liability (asset) [abstract]", "label": "Disclosure of net defined benefit liability (asset) [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfNetDefinedBenefitLiabilityAssetExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNetDefinedBenefitLiabilityAssetExplanatory", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Net Assets Recognised", "label": "Disclosure of net defined benefit liability (asset) [text block]" } }, "en": { "role": { "documentation": "The disclosure of a net defined benefit liability (asset). [Refer: Net defined benefit liability (asset)]" } } }, "auth_ref": [ "r13", "r190" ] }, "ifrs-full_DisclosureOfNetDefinedBenefitLiabilityAssetLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNetDefinedBenefitLiabilityAssetLineItems", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of net defined benefit liability (asset) [line items]", "label": "Disclosure of net defined benefit liability (asset) [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfNetDefinedBenefitLiabilityAssetTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNetDefinedBenefitLiabilityAssetTable", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of net defined benefit liability (asset) [table]", "label": "Disclosure of net defined benefit liability (asset) [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to the net defined benefit liability (asset)." } } }, "auth_ref": [ "r13", "r190" ] }, "san_DisclosureOfNetLoansAndAdvancesToCustomersTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfNetLoansAndAdvancesToCustomersTableTextBlock", "presentation": [ "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Net Loans and Advances to Customers", "label": "Disclosure Of Net Loans And Advances To Customers [Table Text Block]", "documentation": "Disclosure of Loans and advances to customers less impairment losses." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNonadjustingEventsAfterReportingPeriodAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of non-adjusting events after reporting period [abstract]", "label": "Disclosure of non-adjusting events after reporting period [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems", "presentation": [ "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of non-adjusting events after reporting period [line items]", "label": "Disclosure of non-adjusting events after reporting period [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfNonadjustingEventsAfterReportingPeriodTable", "presentation": [ "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of non-adjusting events after reporting period [table]", "label": "Disclosure of non-adjusting events after reporting period [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to non-adjusting events after the reporting period." } } }, "auth_ref": [ "r0", "r181" ] }, "san_DisclosureOfNotionalAndFairValueAmountsOfDerivativeFinancialInstrumentsTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfNotionalAndFairValueAmountsOfDerivativeFinancialInstrumentsTableTextBlock", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of Notional Amounts and Fair Values of Derivatives", "label": "Disclosure Of Notional And Fair Value Amounts Of Derivative Financial Instruments [Table Text Block]", "documentation": "Disclosure of notional amounts and fair values of derivative financial instruments." } } }, "auth_ref": [] }, "san_DisclosureOfOperatingExpensesBeforeCreditImpairmentRestructuringAndSpecificProvisionsTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOperatingExpensesBeforeCreditImpairmentRestructuringAndSpecificProvisionsTableTextBlock", "presentation": [ "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of operating expenses before credit impairment restructuring and specific provisions", "label": "Disclosure Of Operating Expenses Before Credit Impairment, Restructuring And Specific Provisions [Table Text Block]", "documentation": "Disclosure Of Operating Expenses Before Credit Impairment, Restructuring And Specific Provisions" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfOperatingSegmentsAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfOperatingSegmentsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of operating segments [abstract]", "label": "Disclosure of operating segments [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfOperatingSegmentsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfOperatingSegmentsExplanatory", "presentation": [ "http://santander.co.uk/role/SEGMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Results by Segment", "label": "Disclosure of operating segments [text block]" } }, "en": { "role": { "documentation": "The disclosure of operating segments. [Refer: Operating segments [member]]" } } }, "auth_ref": [ "r154" ] }, "ifrs-full_DisclosureOfOperatingSegmentsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfOperatingSegmentsLineItems", "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of operating segments [line items]", "label": "Disclosure of operating segments [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfOperatingSegmentsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfOperatingSegmentsTable", "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of operating segments [table]", "label": "Disclosure of operating segments [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to operating segments." } } }, "auth_ref": [ "r154" ] }, "san_DisclosureOfOtherEquityInstrumentsExplanatoryTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOtherEquityInstrumentsExplanatoryTextBlock", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTS" ], "lang": { "en-us": { "role": { "terseLabel": "OTHER EQUITY INSTRUMENTS", "label": "Disclosure Of Other Equity Instruments Explanatory [Text Block]", "documentation": "The disclosure of other equity instruments." } } }, "auth_ref": [] }, "san_DisclosureOfOtherFinancialAssetsAtAmortisedCostTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOtherFinancialAssetsAtAmortisedCostTextBlock", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOST" ], "lang": { "en-us": { "role": { "terseLabel": "OTHER FINANCIAL ASSETS AT AMORTISED COST", "label": "Disclosure Of Other Financial Assets At Amortised Cost [Text Block]", "documentation": "Disclosure of other financial assets at amortised cost explanatory." } } }, "auth_ref": [] }, "san_DisclosureOfOtherFinancialAssetsAtFairValueThroughProfitOrLossLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOtherFinancialAssetsAtFairValueThroughProfitOrLossLineItems", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Other Financial Assets At Fair Value Through Profit Or Loss [Line Items]", "label": "Disclosure Of Other Financial Assets At Fair Value Through Profit Or Loss [line items]", "documentation": "Disclosure of other financial assets at fair value through profit or loss." } } }, "auth_ref": [] }, "san_DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossExplanatoryTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossExplanatoryTableTextBlock", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Other Financial Liabilities at Fair Value Through Profit or Loss", "label": "Disclosure Of Other Financial Liabilities At Fair Value Through Profit Or Loss Explanatory [Table Text Block]", "documentation": "Disclosure of other financial liabilities at fair value through profit or loss explanatory." } } }, "auth_ref": [] }, "san_DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossLineItems", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Other Financial Liabilities At Fair Value Through Profit Or Loss [Line Items]", "label": "Disclosure Of Other Financial Liabilities At Fair Value Through Profit Or Loss [Line Items]", "documentation": "Disclosure of other financial liabilities at fair value through profit or loss [line items]" } } }, "auth_ref": [] }, "san_DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossTable", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Other Financial Liabilities At Fair Value Through Profit Or Loss [Table]", "label": "Disclosure Of Other Financial Liabilities At Fair Value Through Profit Or Loss [Table]", "documentation": "Disclosure of other financial liabilities at fair value through profit or loss [table]" } } }, "auth_ref": [] }, "san_DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfOtherFinancialLiabilitiesAtFairValueThroughProfitOrLossTextBlock", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSS" ], "lang": { "en-us": { "role": { "terseLabel": "OTHER FINANCIAL LIABILITIES AT FAIR VALUE THROUGH PROFIT OR LOSS", "label": "Disclosure Of Other Financial Liabilities At Fair Value Through Profit Or Loss [Text Block]", "documentation": "Disclosure of other financial liabilities at fair value through profit or loss." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfOtherProvisionsAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfOtherProvisionsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of other provisions [abstract]", "label": "Disclosure of other provisions [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfOtherProvisionsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfOtherProvisionsLineItems", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of other provisions [line items]", "label": "Disclosure of other provisions [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfOtherProvisionsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfOtherProvisionsTable", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of other provisions [table]", "label": "Disclosure of other provisions [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to other provisions." } } }, "auth_ref": [ "r40", "r204" ] }, "ifrs-full_DisclosureOfPropertyPlantAndEquipmentExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfPropertyPlantAndEquipmentExplanatory", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENT" ], "lang": { "en-us": { "role": { "terseLabel": "PROPERTY, PLANT AND EQUIPMENT", "label": "Disclosure of property, plant and equipment [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for property, plant and equipment." } } }, "auth_ref": [ "r11" ] }, "ifrs-full_DisclosureOfPropertyPlantAndEquipmentLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfPropertyPlantAndEquipmentLineItems", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about property, plant and equipment [line items]", "label": "Disclosure of detailed information about property, plant and equipment [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfProvisionsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfProvisionsExplanatory", "presentation": [ "http://santander.co.uk/role/PROVISIONS" ], "lang": { "en-us": { "role": { "terseLabel": "PROVISIONS", "label": "Disclosure of provisions [text block]" } }, "en": { "role": { "documentation": "The disclosure of provisions. [Refer: Provisions]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfProvisionsReconciliationByClassExplanatoryTableTextBlock", "presentation": [ "http://santander.co.uk/role/PROVISIONSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Provisions Reconciliation", "label": "Disclosure Of Provisions Reconciliation By Class Explanatory [Table Text Block]", "documentation": "Summary of Provisions reconciliation by class for the period." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfReconciliationOfChangesInLossAllowanceAndExplanationOfChangesInGrossCarryingAmountForFinancialInstrumentsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfReconciliationOfChangesInLossAllowanceAndExplanationOfChangesInGrossCarryingAmountForFinancialInstrumentsExplanatory", "presentation": [ "http://santander.co.uk/role/CreditRiskTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of ECL Reconciliation", "label": "Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [text block]" } }, "en": { "role": { "documentation": "The disclosure of the reconciliation of changes in the loss allowance and explanation of changes in the gross carrying amount for financial instruments. Loss allowance is the allowance for expected credit losses on financial assets measured in accordance with paragraph 4.1.2 of IFRS 9, lease receivables and contract assets, the accumulated impairment amount for financial assets measured in accordance with paragraph 4.1.2A of IFRS 9 and the provision for expected credit losses on loan commitments and financial guarantee contracts. [Refer: Gross carrying amount [member]]" } } }, "auth_ref": [ "r131", "r132", "r237", "r239" ] }, "ifrs-full_DisclosureOfReconciliationOfChangesInLossAllowanceAndExplanationOfChangesInGrossCarryingAmountForFinancialInstrumentsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfReconciliationOfChangesInLossAllowanceAndExplanationOfChangesInGrossCarryingAmountForFinancialInstrumentsLineItems", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]", "label": "Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfReconciliationOfChangesInLossAllowanceAndExplanationOfChangesInGrossCarryingAmountForFinancialInstrumentsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfReconciliationOfChangesInLossAllowanceAndExplanationOfChangesInGrossCarryingAmountForFinancialInstrumentsTable", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [table]", "label": "Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to the reconciliation of changes in the loss allowance and explanation of changes in the gross carrying amount for financial instruments." } } }, "auth_ref": [ "r131", "r132", "r237", "r239" ] }, "ifrs-full_DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsAbstract", "lang": { "en-us": { "role": { "label": "Disclosure of reconciliation of changes in property, plant and equipment, including right-of-use assets [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsExplanatory", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of reconciliation of changes in property, plant and equipment, including right-of-use assets", "label": "Disclosure of reconciliation of changes in property, plant and equipment, including right-of-use assets [text block]" } }, "en": { "role": { "documentation": "The disclosure of the reconciliation of changes in property, plant and equipment, including right-of-use assets." } } }, "auth_ref": [ "r339" ] }, "ifrs-full_DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfReconciliationOfChangesInPropertyPlantAndEquipmentIncludingRightofuseAssetsTable", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of detailed information about property, plant and equipment [table]", "label": "Disclosure of reconciliation of changes in property, plant and equipment, including right-of-use assets [table]" } }, "en": { "role": { "documentation": "Schedule disclosing the reconciliation of changes in property, plant and equipment, including right-of-use assets." } } }, "auth_ref": [ "r339" ] }, "san_DisclosureOfReconciliationOfChargeResultingFromApplyingUKCorporationTaxRateExplanatoryTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfReconciliationOfChargeResultingFromApplyingUKCorporationTaxRateExplanatoryTableTextBlock", "presentation": [ "http://santander.co.uk/role/TAXATIONTables" ], "lang": { "en-us": { "role": { "terseLabel": "Schedule of Tax on Profit Before Tax Differs from Theoretical Amount that Arise Using Basic Corporation Tax Rate", "label": "Disclosure Of Reconciliation Of Charge Resulting From Applying UK Corporation Tax Rate Explanatory [Table Text Block]", "documentation": "Disclosure of reconciliation of charge resulting from applying UK corporation tax rate." } } }, "auth_ref": [] }, "san_DisclosureOfRegulatoryCapitalResourcesLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfRegulatoryCapitalResourcesLineItems", "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Regulatory Capital Resources [Line Items]", "label": "Disclosure Of Regulatory Capital Resources [Line Items]", "documentation": "Disclosure of regulatory capital resources." } } }, "auth_ref": [] }, "san_DisclosureOfRegulatoryCapitalResourcesTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfRegulatoryCapitalResourcesTable", "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Regulatory Capital Resources [Table]", "label": "Disclosure Of Regulatory Capital Resources [Table]", "documentation": "Disclosure Of Regulatory Capital Resources [table]" } } }, "auth_ref": [] }, "san_DisclosureOfRegulatoryCapitalResourcesTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfRegulatoryCapitalResourcesTableTextBlock", "presentation": [ "http://santander.co.uk/role/CapitalRiskTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Regulatory Capital Resources", "label": "Disclosure Of Regulatory Capital Resources [Table Text Block]", "documentation": "The disclosure of regulatory capital resources." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfRelatedPartyExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfRelatedPartyExplanatory", "presentation": [ "http://santander.co.uk/role/RELATEDPARTYDISCLOSURES" ], "lang": { "en-us": { "role": { "terseLabel": "RELATED PARTY DISCLOSURES", "label": "Disclosure of related party [text block]" } }, "en": { "role": { "documentation": "The entire disclosure for related parties." } } }, "auth_ref": [ "r26" ] }, "san_DisclosureOfRepurchaseAgreementsAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfRepurchaseAgreementsAbstract", "lang": { "en-us": { "role": { "label": "Disclosure Of Repurchase Agreements [Abstract]", "documentation": "Disclosure Of Repurchase Agreements" } } }, "auth_ref": [] }, "san_DisclosureOfRepurchaseAgreementsLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfRepurchaseAgreementsLineItems", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Repurchase Agreements [Line Items]", "label": "Disclosure Of Repurchase Agreements [line items]", "documentation": "Disclosure Of Repurchase Agreements [line items]" } } }, "auth_ref": [] }, "san_DisclosureOfRepurchaseAgreementsTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfRepurchaseAgreementsTable", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Repurchase Agreements [Table]", "label": "Disclosure Of Repurchase Agreements [table]", "documentation": "Disclosure Of Repurchase Agreements [table]" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfRepurchaseAndReverseRepurchaseAgreementsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfRepurchaseAndReverseRepurchaseAgreementsExplanatory", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADING", "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGTables" ], "lang": { "en-us": { "role": { "verboseLabel": "REPURCHASE AGREEMENTS \u2013 NON-TRADING", "terseLabel": "Summary of Reverse Repurchase Agreements - Non Trading", "label": "Disclosure of repurchase and reverse repurchase agreements [text block]" } }, "en": { "role": { "documentation": "The disclosure of repurchase and reverse repurchase agreements." } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfReserveRepurchaseAgreementsNonTradingAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfReserveRepurchaseAgreementsNonTradingAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of reserve repurchase agreements non-trading [abstract]", "label": "Disclosure Of Reserve Repurchase Agreements Non-Trading [Abstract]", "documentation": "Disclosure of reserve repurchase agreements non-trading [abstract]" } } }, "auth_ref": [] }, "san_DisclosureOfReserveRepurchaseAgreementsNonTradingLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfReserveRepurchaseAgreementsNonTradingLineItems", "presentation": [ "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Reserve Repurchase Agreements Non-Trading [Line Items]", "label": "Disclosure Of Reserve Repurchase Agreements Non-Trading [Line Items]", "documentation": "Disclosure of reserve repurchase agreements non-trading [line items]" } } }, "auth_ref": [] }, "san_DisclosureOfReserveRepurchaseAgreementsNonTradingTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfReserveRepurchaseAgreementsNonTradingTable", "presentation": [ "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Reserve Repurchase Agreements Non-Trading [Table]", "label": "Disclosure Of Reserve Repurchase Agreements Non-Trading [Table]", "documentation": "Disclosure of reserve repurchase agreements non-trading [table]" } } }, "auth_ref": [] }, "san_DisclosureOfReverseRepurchaseAgreementsNonTradingTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfReverseRepurchaseAgreementsNonTradingTextBlock", "presentation": [ "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADING" ], "lang": { "en-us": { "role": { "terseLabel": "REVERSE REPURCHASE AGREEMENTS \u2013 NON-TRADING", "label": "Disclosure Of Reverse Repurchase Agreements Non-Trading [Text Block]", "documentation": "The entire disclosure of reverse repurchase agreements non-trading." } } }, "auth_ref": [] }, "san_DisclosureOfSecuritisationsAndCoveredBondsAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSecuritisationsAndCoveredBondsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of securitisations and covered bonds [abstract]", "label": "Disclosure Of Securitisations And Covered Bonds [Abstract]", "documentation": "Disclosure of securitisations and covered bonds abstract." } } }, "auth_ref": [] }, "san_DisclosureOfSecuritisationsAndCoveredBondsExplanatoryTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSecuritisationsAndCoveredBondsExplanatoryTextBlock", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDS" ], "lang": { "en-us": { "role": { "terseLabel": "SECURITISATIONS AND COVERED BONDS", "label": "Disclosure Of Securitisations And Covered Bonds Explanatory [Text Block]", "documentation": "The disclosure of securitisations and covered bonds." } } }, "auth_ref": [] }, "san_DisclosureOfSecuritisationsAndCoveredBondsLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSecuritisationsAndCoveredBondsLineItems", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Securitisations And Covered Bonds [Line Items]", "label": "Disclosure Of Securitisations And Covered Bonds [Line Items]", "documentation": "Disclosure of securitisations and covered bonds line items." } } }, "auth_ref": [] }, "san_DisclosureOfSecuritisationsAndCoveredBondsTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSecuritisationsAndCoveredBondsTable", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Securitisations And Covered Bonds [Table]", "label": "Disclosure Of Securitisations And Covered Bonds [Table]", "documentation": "Disclosure of securitisations and covered bonds." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfSensitivityAnalysisForActuarialAssumptionsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfSensitivityAnalysisForActuarialAssumptionsExplanatory", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Actuarial Assumption Sensitivities", "label": "Disclosure of sensitivity analysis for actuarial assumptions [text block]" } }, "en": { "role": { "documentation": "The disclosure of a sensitivity analysis for significant actuarial assumptions used to determine the present value of a defined benefit obligation. [Refer: Actuarial assumptions [domain]; Defined benefit obligation, at present value]" } } }, "auth_ref": [ "r21" ] }, "ifrs-full_DisclosureOfSensitivityAnalysisForActuarialAssumptionsLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfSensitivityAnalysisForActuarialAssumptionsLineItems", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of sensitivity analysis for actuarial assumptions [line items]", "label": "Disclosure of sensitivity analysis for actuarial assumptions [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfSensitivityAnalysisForActuarialAssumptionsTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfSensitivityAnalysisForActuarialAssumptionsTable", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of sensitivity analysis for actuarial assumptions [table]", "label": "Disclosure of sensitivity analysis for actuarial assumptions [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to the sensitivity analysis for actuarial assumptions." } } }, "auth_ref": [ "r21" ] }, "san_DisclosureOfSensitivityLimitOfRiskLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSensitivityLimitOfRiskLineItems", "presentation": [ "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Sensitivity Limit Of Risk [line items]", "label": "Disclosure Of Sensitivity Limit Of Risk [Line Items]", "documentation": "Disclosure of sensitivity limit of risk." } } }, "auth_ref": [] }, "san_DisclosureOfSensitivityLimitOfRiskTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSensitivityLimitOfRiskTable", "presentation": [ "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure Of Sensitivity Limit Of Risk [table]", "label": "Disclosure Of Sensitivity Limit Of Risk [Table]", "documentation": "Disclosure Of Sensitivity Limit Of Risk [table]" } } }, "auth_ref": [] }, "san_DisclosureOfSignificantAccountingPoliciesAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSignificantAccountingPoliciesAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of significant accounting policies [Abstract]", "label": "Disclosure Of Significant Accounting Policies [Abstract]", "documentation": "Disclosure Of Significant Accounting Policies" } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfSignificantInvestmentsInSubsidiariesLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfSignificantInvestmentsInSubsidiariesLineItems", "presentation": [ "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Investments accounted for using equity method [abstract [Line Items]", "label": "Disclosure of subsidiaries [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfSignificantInvestmentsInSubsidiariesTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfSignificantInvestmentsInSubsidiariesTable", "presentation": [ "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Investments accounted for using equity method [abstract [Table]", "label": "Disclosure of subsidiaries [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to subsidiaries." } } }, "auth_ref": [ "r28", "r29", "r84", "r244" ] }, "ifrs-full_DisclosureOfSignificantUnobservableInputsUsedInFairValueMeasurementOfAssetsExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfSignificantUnobservableInputsUsedInFairValueMeasurementOfAssetsExplanatory", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBTables" ], "lang": { "en-us": { "role": { "terseLabel": "Disclosure of significant unobservable inputs used in fair value measurement of assets", "label": "Disclosure of significant unobservable inputs used in fair value measurement of assets [text block]" } }, "en": { "role": { "documentation": "The disclosure of significant inputs for which market data are not available and that are developed using the best information available about the assumptions that market participants would use when measuring the fair value of assets." } } }, "auth_ref": [ "r88" ] }, "ifrs-full_DisclosureOfSubordinatedLiabilitiesExplanatory": { "xbrltype": "textBlockItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfSubordinatedLiabilitiesExplanatory", "presentation": [ "http://santander.co.uk/role/SUBORDINATEDLIABILITIES" ], "lang": { "en-us": { "role": { "terseLabel": "SUBORDINATED LIABILITIES", "label": "Disclosure of subordinated liabilities [text block]" } }, "en": { "role": { "documentation": "The disclosure of subordinated liabilities. [Refer: Subordinated liabilities]" } } }, "auth_ref": [ "r359" ] }, "san_DisclosureOfSummaryOfOtherEquityInstrumentsTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DisclosureOfSummaryOfOtherEquityInstrumentsTableTextBlock", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Other Equity Instruments", "label": "Disclosure Of Summary Of Other Equity Instruments [Table Text Block]", "documentation": "Disclosure of summary of other equity instruments." } } }, "auth_ref": [] }, "ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisclosureOfTransactionsBetweenRelatedPartiesAbstract", "lang": { "en-us": { "role": { "terseLabel": "Disclosure of transactions between related parties [abstract]", "label": "Disclosure of transactions between related parties [abstract]" } } }, "auth_ref": [] }, "ifrs-full_DiscountRateMeasurementInputMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DiscountRateMeasurementInputMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Discount Rate assumption", "label": "Discount rate, measurement input [member]" } }, "en": { "role": { "documentation": "This member stands for a discount rate used as a measurement input used in valuation techniques based on a present value calculation." } } }, "auth_ref": [ "r355" ] }, "ifrs-full_DisposalsPropertyPlantAndEquipmentIncludingRightofuseAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DisposalsPropertyPlantAndEquipmentIncludingRightofuseAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Disposals", "label": "Disposals, property, plant and equipment including right-of-use assets" } }, "en": { "role": { "documentation": "The decrease in property, plant and equipment including right-of-use assets resulting from disposals. [Refer: Property, plant and equipment including right-of-use assets]" } } }, "auth_ref": [ "r339" ] }, "san_DividendPaidMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DividendPaidMember", "presentation": [ "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Dividend Paid", "label": "Dividend Paid [Member]", "documentation": "Dividend Paid" } } }, "auth_ref": [] }, "san_DividendsOnOrdinarySharesAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DividendsOnOrdinarySharesAbstract", "lang": { "en-us": { "role": { "terseLabel": "Dividends On Ordinary Shares [abstract]", "label": "Dividends On Ordinary Shares [Abstract]", "documentation": "Dividends on ordinary shares." } } }, "auth_ref": [] }, "ifrs-full_DividendsPaid": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DividendsPaid", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Dividend paid", "label": "Dividends recognised as distributions to owners" } }, "en": { "role": { "documentation": "The amount of dividends recognised as distributions to owners." } } }, "auth_ref": [ "r171", "r250", "r262" ] }, "san_DividendsPaidOnPreferenceSharesAndOtherEquityInstrumentsClassifiedAsFinancingActivities": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DividendsPaidOnPreferenceSharesAndOtherEquityInstrumentsClassifiedAsFinancingActivities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": -1.0, "order": 7.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Dividends paid on preference shares and other equity instruments", "label": "Dividends Paid On Preference Shares And Other Equity Instruments, Classified As Financing Activities", "documentation": "Dividends paid on preference shares and other equity instruments classified as financing activities." } } }, "auth_ref": [] }, "ifrs-full_DividendsPaidOrdinaryShares": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "DividendsPaidOrdinaryShares", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/DIVIDENDSONORDINARYSHARESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Dividends paid", "label": "Dividends paid, ordinary shares" } }, "en": { "role": { "documentation": "The amount of dividends paid by the entity on ordinary shares. [Refer: Ordinary shares [member]]" } } }, "auth_ref": [ "r30", "r196" ] }, "san_DividendsRecognisedOnPreferenceSharesAndOtherEquityInstruments": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DividendsRecognisedOnPreferenceSharesAndOtherEquityInstruments", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Dividends on preference shares and other equity instruments", "label": "Dividends Recognised On Preference Shares And Other Equity Instruments", "documentation": "Dividends on preference shares and other equity instruments." } } }, "auth_ref": [] }, "dei_DocumentFiscalPeriodFocus": { "xbrltype": "fiscalPeriodItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "DocumentFiscalPeriodFocus", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Document Fiscal Period Focus", "label": "Document Fiscal Period Focus", "documentation": "Fiscal period values are FY, Q1, Q2, and Q3. 1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY." } } }, "auth_ref": [] }, "dei_DocumentFiscalYearFocus": { "xbrltype": "gYearItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "DocumentFiscalYearFocus", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Document Fiscal Year Focus", "label": "Document Fiscal Year Focus", "documentation": "This is focus fiscal year of the document report in YYYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006." } } }, "auth_ref": [] }, "dei_DocumentPeriodEndDate": { "xbrltype": "dateItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "DocumentPeriodEndDate", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Document Period End Date", "label": "Document Period End Date", "documentation": "For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD." } } }, "auth_ref": [] }, "dei_DocumentType": { "xbrltype": "submissionTypeItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "DocumentType", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Document Type", "label": "Document Type", "documentation": "The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'." } } }, "auth_ref": [] }, "san_DownsideOneScenarioMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DownsideOneScenarioMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Downside 1", "label": "Downside One Scenario [member]", "documentation": "Downside One." } } }, "auth_ref": [] }, "san_DownsideTwoScenarioMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DownsideTwoScenarioMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Downside 2", "label": "Downside Two Scenario [Member]", "documentation": "Downside two." } } }, "auth_ref": [] }, "san_DownstreamedFromSantanderUKGroupHoldingsPlcToSantanderUKPLCMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DownstreamedFromSantanderUKGroupHoldingsPlcToSantanderUKPLCMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Downstreamed from Santander UK Group Holdings plc to Santander UK plc", "label": "Downstreamed From Santander UK Group Holdings plc To Santander UK PLC [Member]", "documentation": "Downstreamed From Santander UK Group Holdings plc To Santander UK PLC" } } }, "auth_ref": [] }, "san_DrawdownFromTermFundingSchemeForSME": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DrawdownFromTermFundingSchemeForSME", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Drawdown from TFSME", "label": "Drawdown From Term Funding Scheme for SME", "documentation": "Drawdown From Term Funding Scheme for SME" } } }, "auth_ref": [] }, "san_DuncanMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "DuncanMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "\u2013 Duncan", "label": "Duncan [Member]", "documentation": "Duncan" } } }, "auth_ref": [] }, "san_ECLChargeReleaseToTheIncomeStatementFromContinuedOperations": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ECLChargeReleaseToTheIncomeStatementFromContinuedOperations", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Total ECL charge to the Income Statement", "label": "ECL Charge/(Release) To The Income Statement From Continued Operations", "documentation": "ECL Charge/(Release) To The Income Statement From Continued Operations" } } }, "auth_ref": [] }, "san_ECLOnUndrawnFacilitiesAndGuaranteesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ECLOnUndrawnFacilitiesAndGuaranteesMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "ECL on undrawn facilities and guarantees", "label": "ECL On Undrawn Facilities And Guarantees [Member]", "documentation": "ECL On Undrawn Facilities And Guarantees" } } }, "auth_ref": [] }, "ifrs-full_EffectOfExchangeRateChangesOnCashAndCashEquivalents": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "EffectOfExchangeRateChangesOnCashAndCashEquivalents", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Effects of exchange rate changes on cash and cash equivalents", "label": "Effect of exchange rate changes on cash and cash equivalents" } }, "en": { "role": { "documentation": "The effect of exchange rate changes on cash and cash equivalents held or due in a foreign currency. [Refer: Cash and cash equivalents]" } } }, "auth_ref": [ "r58", "r59" ] }, "ifrs-full_EliminationOfIntersegmentAmountsMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "EliminationOfIntersegmentAmountsMember", "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Inter-segment (expense)/revenue", "label": "Elimination of intersegment amounts [member]" } }, "en": { "role": { "documentation": "This member stands for the elimination of intersegment amounts in the reconciliations of total segment amounts to amounts recognised in the entity's financial statements." } } }, "auth_ref": [ "r318", "r319" ] }, "ifrs-full_EmployeeBenefitsExpense": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "EmployeeBenefitsExpense", "crdr": "debit", "calculation": { "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails": { "parentTag": "san_OperatingExpensesBeforeCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Staff costs", "label": "Employee benefits expense" } } }, "auth_ref": [ "r169", "r255", "r281", "r329" ] }, "dei_EntityCentralIndexKey": { "xbrltype": "centralIndexKeyItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "EntityCentralIndexKey", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Entity Central Index Key", "label": "Entity Central Index Key", "documentation": "A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK." } } }, "auth_ref": [ "r336" ] }, "dei_EntityRegistrantName": { "xbrltype": "normalizedStringItemType", "nsuri": "http://xbrl.sec.gov/dei/2025", "localname": "EntityRegistrantName", "presentation": [ "http://santander.co.uk/role/CoverPage" ], "lang": { "en-us": { "role": { "terseLabel": "Entity Registrant Name", "label": "Entity Registrant Name", "documentation": "The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC." } } }, "auth_ref": [ "r336" ] }, "ifrs-full_Equity": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Equity", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_EquityAndLiabilities", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Total equity", "periodStartLabel": "Beginning balance", "periodEndLabel": "Ending balance", "label": "Equity" } }, "en": { "role": { "documentation": "The amount of residual interest in the assets of the entity after deducting all its liabilities." } } }, "auth_ref": [ "r71", "r73", "r85", "r86", "r91", "r194", "r216", "r246", "r247", "r252", "r269", "r271" ] }, "ifrs-full_EquityAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "EquityAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Equity", "label": "Equity [abstract]" } } }, "auth_ref": [] }, "san_EquityAndCreditContractsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "EquityAndCreditContractsMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Equity and credit contracts", "label": "Equity And Credit Contracts [Member]", "documentation": "Equity and credit contracts." } } }, "auth_ref": [] }, "ifrs-full_EquityAndLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "EquityAndLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Total liabilities and equity", "label": "Equity and liabilities" } }, "en": { "role": { "documentation": "The amount of the entity's equity and liabilities. [Refer: Equity; Liabilities]" } } }, "auth_ref": [ "r269" ] }, "san_EquityIndexLinkedDepositsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "EquityIndexLinkedDepositsMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Equity index linked deposits", "label": "Equity Index Linked Deposits [Member]", "documentation": "Equity index linked deposits." } } }, "auth_ref": [] }, "ifrs-full_EstimatedFinancialEffectOfContingentLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "EstimatedFinancialEffectOfContingentLiabilities", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Estimated effect of litigation", "label": "Estimated financial effect of contingent liabilities" } }, "en": { "role": { "documentation": "The amount of the estimated financial effect of contingent liabilities. [Refer: Classes of contingent liabilities [domain]]" } } }, "auth_ref": [ "r41", "r205" ] }, "san_EstimatedFinancialEffectOfContingentLiabilitiesAndCommitments": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "EstimatedFinancialEffectOfContingentLiabilitiesAndCommitments", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Guarantees and formal standby facilities, credit lines and other commitments", "label": "Estimated Financial Effect Of Contingent Liabilities And Commitments", "documentation": "Estimated financial effect of contingent liabilities and commitments." } } }, "auth_ref": [] }, "san_EuroThirtyFiveBillionGlobalCoveredBondProgrammeMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "EuroThirtyFiveBillionGlobalCoveredBondProgrammeMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Euro \u20ac35bn Global Covered Bond Programme", "label": "Euro Thirty Five Billion Global Covered Bond Programme [Member]", "documentation": "Euro thirty five billion global covered bond programme." } } }, "auth_ref": [] }, "san_ExchangeRateContractsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ExchangeRateContractsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Exchange rate contracts", "label": "Exchange Rate Contracts [Member]", "documentation": "Exchange rate contracts." } } }, "auth_ref": [] }, "san_ExpectedCreditLossMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ExpectedCreditLossMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "ECL", "label": "Expected Credit Loss [Member]", "documentation": "Expected credit loss." } } }, "auth_ref": [] }, "ifrs-full_ExpenseByNatureAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ExpenseByNatureAbstract", "lang": { "en-us": { "role": { "terseLabel": "Expenses by nature [abstract]", "label": "Expenses by nature [abstract]" } } }, "auth_ref": [] }, "san_ExternalMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ExternalMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "External", "label": "External [Member]", "documentation": "External." } } }, "auth_ref": [] }, "san_FairValueAdjustmentMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FairValueAdjustmentMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "FV Adjustments", "label": "Fair Value Adjustment [Member]", "documentation": "Fair Value Adjustment" } } }, "auth_ref": [] }, "san_FairValueAdjustments": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FairValueAdjustments", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair value adjustments", "label": "Fair Value Adjustments", "documentation": "Fair value adjustments risk." } } }, "auth_ref": [] }, "san_FairValueAdjustmentsAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FairValueAdjustmentsAxis", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair Value Adjustments [Axis]", "label": "Fair Value Adjustments [Axis]", "documentation": "Fair value adjustments axis." } } }, "auth_ref": [] }, "san_FairValueAdjustmentsClassificationAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FairValueAdjustmentsClassificationAxis", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair Value Adjustments, Classification [Axis]", "label": "Fair Value Adjustments, Classification [Axis]", "documentation": "Fair Value Adjustments, Classification" } } }, "auth_ref": [] }, "san_FairValueAdjustmentsClassificationDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FairValueAdjustmentsClassificationDomain", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair Value Adjustments, Classification [Domain]", "label": "Fair Value Adjustments, Classification [Domain]", "documentation": "Fair Value Adjustments, Classification [Domain]" } } }, "auth_ref": [] }, "san_FairValueAdjustmentsDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FairValueAdjustmentsDomain", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair Value Adjustments [Domain]", "label": "Fair Value Adjustments [Domain]", "documentation": "Fair Value Adjustments [domain]" } } }, "auth_ref": [] }, "ifrs-full_FairValueHedgesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FairValueHedgesMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Designated as fair value hedges:", "label": "Fair value hedges [member]" } }, "en": { "role": { "documentation": "This member stands for hedges of the exposure to changes in fair value of a recognised asset or liability or an unrecognised firm commitment, or an identified portion of such an asset, liability or firm commitment, that is attributable to a particular risk and could affect profit or loss. [Refer: Types of hedges [domain]]" } } }, "auth_ref": [ "r48", "r124", "r125", "r126", "r231", "r232", "r233" ] }, "ifrs-full_FairValueOfAcquiredReceivables": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FairValueOfAcquiredReceivables", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair value of acquired receivables", "label": "Fair value of acquired receivables" } }, "en": { "role": { "documentation": "The fair value of receivables acquired in a business combination. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r108" ] }, "san_FairValuesOfFinancialInstrumentsValuationTechniqueUsed": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FairValuesOfFinancialInstrumentsValuationTechniqueUsed", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Valuation technique", "label": "Fair Values Of Financial Instruments Valuation Technique Used", "documentation": "Fair values of financial instruments valuation technique used." } } }, "auth_ref": [] }, "ifrs-full_FeeAndCommissionExpense": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FeeAndCommissionExpense", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_FeeAndCommissionIncomeExpense", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Fee and commission expense", "label": "Fee and commission expense" } } }, "auth_ref": [ "r367" ] }, "ifrs-full_FeeAndCommissionIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FeeAndCommissionIncome", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_FeeAndCommissionIncomeExpense", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Fee and commission income", "label": "Fee and commission income" } } }, "auth_ref": [ "r367" ] }, "ifrs-full_FeeAndCommissionIncomeExpense": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FeeAndCommissionIncomeExpense", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "san_NetOperatingIncome", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Net fee and commission income", "label": "Fee and commission income (expense)" } } }, "auth_ref": [ "r367" ] }, "ifrs-full_FinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Financial assets", "periodStartLabel": "Beginning balance", "periodEndLabel": "Ending balance", "totalLabel": "Total financial assets", "label": "Financial assets" } }, "en": { "role": { "documentation": "The amount of assets that are: (a) cash; (b) an equity instrument of another entity; (c) a contractual right: (i) to receive cash or another financial asset from another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially favourable to the entity; or (d) a contract that will, or may be, settled in the entity\u2019s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to receive a variable number of the entity\u2019s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity\u2019s own equity instruments. For this purpose the entity\u2019s own equity instruments do not include puttable financial instruments classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity\u2019s own equity instruments. [Refer: Classes of financial instruments [domain]; Financial liabilities]" } } }, "auth_ref": [ "r127", "r131", "r132", "r137", "r237", "r239", "r243", "r310" ] }, "san_FinancialAssetsAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FinancialAssetsAbstract", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Assets", "label": "Financial Assets [Abstract]", "documentation": "Financial Assets" } } }, "auth_ref": [] }, "ifrs-full_FinancialAssetsAtAmortisedCostMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtAmortisedCostMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial assets at amortised cost", "label": "Financial assets at amortised cost, class [member]" } }, "en": { "role": { "documentation": "This member stands for the financial assets measured at amortised cost class. [Refer: Financial assets at amortised cost]" } } }, "auth_ref": [ "r147", "r165", "r230" ] }, "ifrs-full_FinancialAssetsAtFairValue": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtFairValue", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Assets at fair value", "label": "Financial assets, at fair value" } }, "en": { "role": { "documentation": "The fair value of financial assets. [Refer: At fair value [member]; Financial assets]" } } }, "auth_ref": [ "r127" ] }, "ifrs-full_FinancialAssetsAtFairValueMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtFairValueMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial assets at fair value", "label": "Financial assets at fair value, class [member]" } }, "en": { "role": { "documentation": "This member stands for the financial assets measured at fair value class. [Refer: Financial assets; At fair value [member]]" } } }, "auth_ref": [ "r147" ] }, "ifrs-full_FinancialAssetsAtFairValueThroughOtherComprehensiveIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtFairValueThroughOtherComprehensiveIncome", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 10.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "verboseLabel": "Financial assets at fair value through other comprehensive income", "label": "Financial assets at fair value through other comprehensive income" } }, "en": { "role": { "documentation": "The amount of financial assets at fair value through other comprehensive income. [Refer: At fair value [member]; Financial assets; Other comprehensive income]" } } }, "auth_ref": [ "r145", "r226" ] }, "ifrs-full_FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeCategoryMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeCategoryMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial assets at FVOCI", "label": "Financial assets at fair value through other comprehensive income, category [member]" } }, "en": { "role": { "documentation": "This member stands for the financial assets at fair value through other comprehensive income category. [Refer: Financial assets at fair value through other comprehensive income]" } } }, "auth_ref": [ "r145", "r226" ] }, "san_FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 7.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial assets at fair value through other comprehensive income", "label": "Financial Assets At Fair Value Through Other Comprehensive Income Recognised As Of Acquisition Date", "documentation": "Financial Assets At Fair Value Through Other Comprehensive Income Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLoss": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtFairValueThroughProfitOrLoss", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial assets at fair value through profit or loss", "label": "Financial assets at fair value through profit or loss" } }, "en": { "role": { "documentation": "The amount of financial assets that are measured at fair value and for which gains (losses) are recognised in profit or loss. A financial asset shall be measured at fair value through profit or loss unless it is measured at amortised cost or at fair value through other comprehensive income. A gain (loss) on a financial asset measured at fair value shall be recognised in profit or loss unless it is part of a hedging relationship, it is an investment in an equity instrument for which the entity has elected to present gains and losses in other comprehensive income or it is a financial asset measured at fair value through other comprehensive income. [Refer: At fair value [member]; Financial assets]" } } }, "auth_ref": [ "r142", "r223" ] }, "ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLossAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtFairValueThroughProfitOrLossAbstract", "lang": { "en-us": { "role": { "terseLabel": "Financial assets at fair value through profit or loss [abstract]", "label": "Financial assets at fair value through profit or loss [abstract]" } } }, "auth_ref": [] }, "ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial assets at FVTPL", "label": "Financial assets at fair value through profit or loss, category [member]" } }, "en": { "role": { "documentation": "This member stands for the financial assets at fair value through profit or loss category. [Refer: Financial assets at fair value through profit or loss]" } } }, "auth_ref": [ "r142", "r223" ] }, "san_FinancialAssetsAtFairValueThroughProfitOrLossLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FinancialAssetsAtFairValueThroughProfitOrLossLineItems", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial Assets At Fair Value Through Profit Or Loss [Line Items]", "label": "Financial Assets At Fair Value Through Profit Or Loss [Line Items]", "documentation": "Financial Assets At Fair Value Through Profit Or Loss" } } }, "auth_ref": [] }, "san_FinancialAssetsAtFairValueThroughProfitOrLossTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FinancialAssetsAtFairValueThroughProfitOrLossTable", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial Assets At Fair Value Through Profit Or Loss [Table]", "label": "Financial Assets At Fair Value Through Profit Or Loss [table]", "documentation": "Financial assets at fair value through profit or loss." } } }, "auth_ref": [] }, "ifrs-full_FinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Movement in fair value reserve (debt instruments):", "label": "Financial assets measured at fair value through other comprehensive income [abstract]" } } }, "auth_ref": [] }, "ifrs-full_FinancialAssetsPledgedAsCollateralForLiabilitiesOrContingentLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialAssetsPledgedAsCollateralForLiabilitiesOrContingentLiabilities", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial assets pledged as collateral for liabilities or contingent liabilities", "label": "Financial assets pledged as collateral for liabilities or contingent liabilities" } }, "en": { "role": { "documentation": "The amount of financial assets that the entity has pledged as collateral for liabilities or contingent liabilities, including amounts that have been reclassified in accordance with paragraph 3.2.23(a) of IFRS 9. [Refer: Classes of contingent liabilities [domain]; Financial assets]" } } }, "auth_ref": [ "r122", "r228" ] }, "san_FinancialAssetsPostWriteoffRecoveries": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FinancialAssetsPostWriteoffRecoveries", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails": { "parentTag": "ifrs-full_ImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails", "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Less: Recoveries net of collection costs", "verboseLabel": "Recoveries of loans and advances, net of collection costs", "label": "Financial Assets Post Writeoff Recoveries", "documentation": "Financial assets post write-off recoveries." } } }, "auth_ref": [] }, "ifrs-full_FinancialInstrumentsCreditimpairedMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialInstrumentsCreditimpairedMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial instruments credit-impaired", "label": "Financial instruments credit-impaired [member]" } }, "en": { "role": { "documentation": "This member stands for financial instruments that are credit-impaired. [Refer: Credit impairment of financial instruments [domain]]" } } }, "auth_ref": [ "r131", "r137", "r237", "r243" ] }, "ifrs-full_FinancialInstrumentsNotCreditimpairedMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialInstrumentsNotCreditimpairedMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial instruments not credit-impaired", "label": "Financial instruments not credit-impaired [member]" } }, "en": { "role": { "documentation": "This member stands for financial instruments that are not credit-impaired. [Refer: Credit impairment of financial instruments [domain]]" } } }, "auth_ref": [ "r131", "r137", "r237", "r243" ] }, "ifrs-full_FinancialInstrumentsPurchasedOrOriginatedCreditimpairedMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialInstrumentsPurchasedOrOriginatedCreditimpairedMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "POCI", "label": "Financial instruments purchased or originated credit-impaired [member]" } }, "en": { "role": { "documentation": "This member stands for financial instruments that were purchased or originated as credit-impaired. [Refer: Financial instruments credit-impaired [member]]" } } }, "auth_ref": [ "r130", "r136", "r236", "r242" ] }, "ifrs-full_FinancialLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial liabilities", "totalLabel": "Total financial liabilities", "label": "Financial liabilities" } }, "en": { "role": { "documentation": "The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity\u2019s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity\u2019s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity\u2019s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity\u2019s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity\u2019s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity\u2019s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Classes of financial instruments [domain]; Financial assets; Derivatives [member]]" } } }, "auth_ref": [ "r127" ] }, "san_FinancialLiabilitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FinancialLiabilitiesAbstract", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial Liabilities [Abstract]", "label": "Financial Liabilities [Abstract]", "documentation": "Financial Liabilities" } } }, "auth_ref": [] }, "ifrs-full_FinancialLiabilitiesAtAmortisedCostCategoryMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialLiabilitiesAtAmortisedCostCategoryMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial liabilities at amortised cost", "label": "Financial liabilities at amortised cost, category [member]" } }, "en": { "role": { "documentation": "This member stands for the financial liabilities at amortised cost category. [Refer: Financial liabilities at amortised cost]" } } }, "auth_ref": [ "r144", "r225" ] }, "ifrs-full_FinancialLiabilitiesAtFairValue": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialLiabilitiesAtFairValue", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Liabilities at fair value", "label": "Financial liabilities, at fair value" } }, "en": { "role": { "documentation": "The fair value of financial liabilities. [Refer: At fair value [member]; Financial liabilities]" } } }, "auth_ref": [ "r127" ] }, "ifrs-full_FinancialLiabilitiesAtFairValueMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialLiabilitiesAtFairValueMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial liabilities at fair value", "label": "Financial liabilities at fair value, class [member]" } }, "en": { "role": { "documentation": "This member stands for the financial liabilities measured at fair value class. [Refer: Financial liabilities; At fair value [member]]" } } }, "auth_ref": [ "r147" ] }, "ifrs-full_FinancialLiabilitiesAtFairValueThroughProfitOrLossDesignatedUponInitialRecognitionCategoryMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "FinancialLiabilitiesAtFairValueThroughProfitOrLossDesignatedUponInitialRecognitionCategoryMember", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Financial liabilities at fair value through profit or loss, designated upon initial recognition or subsequently, category", "label": "Financial liabilities at fair value through profit or loss, designated upon initial recognition or subsequently, category [member]" } }, "en": { "role": { "documentation": "This member stands for the financial liabilities at fair value through profit or loss designated as such upon initial recognition or subsequently category. [Refer: Financial liabilities at fair value through profit or loss, designated upon initial recognition or subsequently]" } } }, "auth_ref": [ "r143", "r224" ] }, "san_FiveHundredMillionFixedRateResetPerpetualAtOneCapitalSecuritiesThreeMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FiveHundredMillionFixedRateResetPerpetualAtOneCapitalSecuritiesThreeMember", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- \u00a3500m Fixed Rate Reset Perpetual Capital Securities", "label": "Five Hundred Million Fixed Rate Reset Perpetual AT One Capital Securities Three [Member]", "documentation": "Five hundred million fixed rate reset perpetual AT1 capital securities three." } } }, "auth_ref": [] }, "san_FixedToFloatingRateCallableSubordinatedTier2CapitalNotesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FixedToFloatingRateCallableSubordinatedTier2CapitalNotesMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fixed-to-floating rate callable subordinated Tier 2 capital notes", "label": "Fixed-to-Floating Rate Callable Subordinated Tier 2 Capital Notes [Member]", "documentation": "Fixed-to-Floating Rate Callable Subordinated Tier 2 Capital Notes" } } }, "auth_ref": [] }, "san_FosseMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FosseMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fosse", "label": "Fosse [Member]", "documentation": "Fosse." } } }, "auth_ref": [] }, "san_FourHundredAndTenMillionPerpetualCapitalSecuritiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FourHundredAndTenMillionPerpetualCapitalSecuritiesMember", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- \u00a3410m Perpetual Capital Securities", "label": "Four Hundred and Ten Million Perpetual Capital Securities [Member]", "documentation": "Four Hundred and Ten Million Perpetual Capital Securities" } } }, "auth_ref": [] }, "san_FourHundredMillionFixedRateResetPerpetualATOneCapitalSecuritiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FourHundredMillionFixedRateResetPerpetualATOneCapitalSecuritiesMember", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- \u00a3400m Perpetual Capital Securities", "label": "Four Hundred Million Fixed Rate Reset Perpetual AT One Capital Securities [Member]", "documentation": "Four Hundred Million Fixed Rate Reset Perpetual AT One Capital Securities" } } }, "auth_ref": [] }, "san_FraudLossMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FraudLossMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fraud losses", "label": "Fraud Loss [Member]", "documentation": "Fraud Loss" } } }, "auth_ref": [] }, "san_FullServiceBranchesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FullServiceBranchesMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Full service branches", "label": "Full Service Branches [Member]", "documentation": "Full Service Branches" } } }, "auth_ref": [] }, "san_FundingSpreadMeasurementInputMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "FundingSpreadMeasurementInputMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Funding spread assumption", "label": "Funding Spread, Measurement Input [Member]", "documentation": "Funding Spread" } } }, "auth_ref": [] }, "ifrs-full_GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset", "crdr": "debit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails" ], "lang": { "en-us": { "role": { "negatedTotalLabel": "Pension remeasurement", "label": "Decrease (increase) in net defined benefit liability (asset) resulting from gain (loss) on remeasurement in other comprehensive income" } }, "en": { "role": { "documentation": "The decrease (increase) in a net defined benefit liability (asset) resulting from the remeasurement of that net defined benefit liability (asset). [Refer: Net defined benefit liability (asset)]" } } }, "auth_ref": [ "r17", "r191" ] }, "san_GainLossOnRepurchaseOfSubordinatedLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "GainLossOnRepurchaseOfSubordinatedLiabilities", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SUBORDINATEDLIABILITIESAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Gain (loss) on repurchase of subordinated liabilities", "label": "Gain (Loss) On Repurchase Of Subordinated Liabilities", "documentation": "Gain (Loss) On Repurchase Of Subordinated Liabilities" } } }, "auth_ref": [] }, "ifrs-full_GainsLossesOnCashFlowHedgesBeforeTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GainsLossesOnCashFlowHedgesBeforeTax", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxCashFlowHedges", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "- Effective portion of changes in fair value", "label": "Gains (losses) on cash flow hedges, before tax" } }, "en": { "role": { "documentation": "The gains (losses) recognised in other comprehensive income on cash flow hedges, before tax, before reclassification adjustments. [Refer: Cash flow hedges [member]]" } } }, "auth_ref": [ "r278" ] }, "ifrs-full_GainsLossesOnChangeInValueOfTimeValueOfOptionsBeforeTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GainsLossesOnChangeInValueOfTimeValueOfOptionsBeforeTax", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxChangeInValueOfTimeValueOfOptions", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "- Cost of hedging gains", "label": "Gains (losses) on change in value of time value of options, before tax" } }, "en": { "role": { "documentation": "The gains (losses) recognised in other comprehensive income on change in value of time value of options, before tax, before reclassification adjustments. [Refer: Other comprehensive income]" } } }, "auth_ref": [ "r278" ] }, "ifrs-full_GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeNetOfTax", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "- Change in fair value", "label": "Gains (losses) on financial assets measured at fair value through other comprehensive income, before tax" } }, "en": { "role": { "documentation": "The gains (losses) recognised in other comprehensive income on financial assets measured at fair value through other comprehensive income applying paragraph 4.1.2A of IFRS 9, before tax, before reclassification adjustments. [Refer: Financial assets measured at fair value through other comprehensive income; Other comprehensive income]" } } }, "auth_ref": [ "r123", "r229", "r278" ] }, "ifrs-full_GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeNetOfTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeNetOfTax", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncome", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Other comprehensive income, fair value reserve (debt instruments)", "terseLabel": "- Fair value reserve (debt instruments)", "label": "Gains (losses) on financial assets measured at fair value through other comprehensive income, net of tax" } }, "en": { "role": { "documentation": "The gains (losses) recognised in other comprehensive income on financial assets measured at fair value through other comprehensive income applying paragraph 4.1.2A of IFRS 9, net of tax, before reclassification adjustments. [Refer: Financial assets measured at fair value through other comprehensive income; Other comprehensive income]" } } }, "auth_ref": [ "r277" ] }, "ifrs-full_GainsLossesRecognisedInProfitOrLossFairValueMeasurementAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GainsLossesRecognisedInProfitOrLossFairValueMeasurementAssets", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair value movements", "label": "Gains (losses) recognised in profit or loss including exchange differences, fair value measurement, assets" } }, "en": { "role": { "documentation": "The gains (losses) including exchange differences recognised in profit or loss on the fair value measurement of assets. [Refer: At fair value [member]]" } } }, "auth_ref": [ "r89", "r248" ] }, "ifrs-full_GainsLossesRecognisedInProfitOrLossFairValueMeasurementLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GainsLossesRecognisedInProfitOrLossFairValueMeasurementLiabilities", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Fair value movements", "label": "Gains (losses) recognised in profit or loss including exchange differences, fair value measurement, liabilities" } }, "en": { "role": { "documentation": "The gains (losses) including exchange differences recognised in profit or loss on the fair value measurement of liabilities. [Refer: At fair value [member]]" } } }, "auth_ref": [ "r89", "r248" ] }, "ifrs-full_Goodwill": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Goodwill", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESCriticaljudgementsandaccountingestimatesDetails", "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Goodwill", "verboseLabel": "Goodwill", "label": "Goodwill" } }, "en": { "role": { "documentation": "The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r34", "r36", "r116", "r198", "r200", "r221", "r265" ] }, "ifrs-full_GoodwillRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GoodwillRecognisedAsOfAcquisitionDate", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Goodwill arising on acquisition", "label": "Goodwill recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the business combination's acquisition date for goodwill. [Refer: Goodwill; Total for all business combinations [member]]" } } }, "auth_ref": [ "r302", "r303", "r321" ] }, "ifrs-full_GrossCarryingAmountMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GrossCarryingAmountMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails", "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails", "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Cost", "terseLabel": "Cost:", "label": "Gross carrying amount [member]" } } }, "auth_ref": [ "r7", "r45", "r52", "r55", "r116", "r132", "r137", "r185", "r208", "r212", "r215", "r239", "r243", "r310" ] }, "ifrs-full_GrossContractualAmountsReceivableForAcquiredReceivables": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "GrossContractualAmountsReceivableForAcquiredReceivables", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Gross contractual amounts receivable for acquired receivables", "label": "Gross contractual amounts receivable for acquired receivables" } }, "en": { "role": { "documentation": "The gross contractual amounts receivable for receivables acquired in business combinations. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r109" ] }, "san_GrossImpairmentLossIncomeStatementCharge": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "GrossImpairmentLossIncomeStatementCharge", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "ECL charge to the Income Statement", "label": "Gross Impairment Loss, Income Statement Charge", "documentation": "Gross impairment loss, income statement charge." } } }, "auth_ref": [] }, "san_GuaranteesGivenToThirdParties": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "GuaranteesGivenToThirdParties", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails": { "parentTag": "san_EstimatedFinancialEffectOfContingentLiabilitiesAndCommitments", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Guarantees given to third parties", "label": "Guarantees Given To Third Parties", "documentation": "Guarantees Given To Third Parties" } } }, "auth_ref": [] }, "san_HolmesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "HolmesMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Holmes", "label": "Holmes [member]", "documentation": "Holmes." } } }, "auth_ref": [] }, "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IdentifiableAssetsAcquiredLiabilitiesAssumed", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Fair value of net assets acquired", "label": "Identifiable assets acquired (liabilities assumed)" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for net identifiable assets acquired or liabilities assumed in a business combination. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r301", "r303", "r320" ] }, "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Total assets", "label": "Identifiable Assets Acquired Recognised As Of Acquisition Date", "documentation": "Identifiable Assets Acquired Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "ifrs-full_IdentifiableIntangibleAssetsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IdentifiableIntangibleAssetsRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 8.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Intangible assets", "label": "Identifiable intangible assets recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for identifiable intangible assets acquired in a business combination. [Refer: Intangible assets other than goodwill; Total for all business combinations [member]]" } } }, "auth_ref": [ "r301", "r303", "r320" ] }, "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Total liabilities", "label": "Identifiable Liabilities Acquired Recognised As Of Acquisition Date", "documentation": "Identifiable Liabilities Acquired Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "ifrs-full_ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipmentIncludingRightofuseAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipmentIncludingRightofuseAssets", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impairment during the period", "label": "Impairment loss recognised in profit or loss, property, plant and equipment including right-of-use assets" } } }, "auth_ref": [ "r339" ] }, "ifrs-full_ImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "san_AggregateOperatingCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Credit impairment charges", "totalLabel": "Credit impairment charges/(write-backs):", "label": "Impairment loss (reversal of impairment loss) recognised in profit or loss" } } }, "auth_ref": [ "r170", "r281" ] }, "san_ImpairmentOfPropertyMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ImpairmentOfPropertyMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impairment of property", "label": "Impairment Of Property [Member]", "documentation": "Impairment Of Property" } } }, "auth_ref": [] }, "ifrs-full_IncomeTaxExpenseContinuingOperations": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncomeTaxExpenseContinuingOperations", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_ProfitLoss", "weight": -1.0, "order": 2.0 }, "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Tax on profit", "negatedTerseLabel": "Tax on profit", "totalLabel": "Tax on profit", "label": "Tax expense (income)" } } }, "auth_ref": [ "r2", "r4", "r5", "r27", "r83", "r153", "r182", "r183", "r184", "r275" ] }, "ifrs-full_IncomeTaxRelatingToCashFlowHedgesOfOtherComprehensiveIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncomeTaxRelatingToCashFlowHedgesOfOtherComprehensiveIncome", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxCashFlowHedges", "weight": -1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "- Taxation", "label": "Income tax relating to cash flow hedges included in other comprehensive income" } }, "en": { "role": { "documentation": "The amount of income tax relating to amounts recognised in other comprehensive income in relation to cash flow hedges. [Refer: Cash flow hedges [member]; Other comprehensive income]" } } }, "auth_ref": [ "r3", "r276" ] }, "ifrs-full_IncomeTaxRelatingToChangesInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiabilityOfOtherComprehensiveIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncomeTaxRelatingToChangesInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiabilityOfOtherComprehensiveIncome", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiability", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "- Taxation", "label": "Income tax relating to changes in fair value of financial liability attributable to change in credit risk of liability included in other comprehensive income" } }, "en": { "role": { "documentation": "The amount of income tax relating to amounts recognised in other comprehensive income in relation to changes in the fair value of financial liabilities attributable to a change in the credit risk of those liabilities. [Refer: Credit risk [member]; Other comprehensive income]" } } }, "auth_ref": [ "r3", "r276" ] }, "ifrs-full_IncomeTaxRelatingToFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncomeTaxRelatingToFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeNetOfTax", "weight": -1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "- Taxation", "label": "Income tax relating to financial assets measured at fair value through other comprehensive income included in other comprehensive income" } }, "en": { "role": { "documentation": "The amount of income tax relating to amounts recognised in other comprehensive income in relation to financial assets measured at fair value through other comprehensive income applying paragraph 4.1.2A of IFRS 9. [Refer: Financial assets measured at fair value through other comprehensive income; Other comprehensive income]" } } }, "auth_ref": [ "r3", "r276" ] }, "ifrs-full_IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncome", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "- Taxation", "label": "Income tax relating to remeasurements of defined benefit plans included in other comprehensive income" } }, "en": { "role": { "documentation": "The amount of income tax relating to amounts recognised in other comprehensive income in relation to remeasurements of defined benefit plans. [Refer: Other comprehensive income; Reserve of remeasurements of defined benefit plans; Defined benefit plans [domain]]" } } }, "auth_ref": [ "r3", "r276" ] }, "ifrs-full_IncomeTaxesPaidClassifiedAsOperatingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncomeTaxesPaidClassifiedAsOperatingActivities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Corporation taxes paid", "label": "Income taxes paid, classified as operating activities" } }, "en": { "role": { "documentation": "The cash outflow for income taxes paid, classified as operating activities." } } }, "auth_ref": [ "r354" ] }, "ifrs-full_IncreaseDecreaseDueToVoluntaryChangesInAccountingPolicyMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseDueToVoluntaryChangesInAccountingPolicyMember", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Change", "label": "Increase (decrease) due to voluntary changes in accounting policy [member]" } }, "en": { "role": { "documentation": "This member stands for the financial effect of voluntary changes in accounting policy." } } }, "auth_ref": [ "r66", "r67", "r176", "r177" ] }, "ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Change in cash and cash equivalents", "label": "Increase (decrease) in cash and cash equivalents before effect of exchange rate changes" } }, "en": { "role": { "documentation": "The increase (decrease) in cash and cash equivalents before the effect of exchange rate changes on cash and cash equivalents held in foreign currencies. [Refer: Cash and cash equivalents; Effect of exchange rate changes on cash and cash equivalents]" } } }, "auth_ref": [ "r63", "r173" ] }, "ifrs-full_IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleIncreaseInActuarialAssumption": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleIncreaseInActuarialAssumption", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Increase (decrease) in defined benefit obligation", "label": "Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption" } }, "en": { "role": { "documentation": "The increase (decrease) in a defined benefit obligation that would have been caused by an increase in a significant actuarial assumption that was reasonably possible at the end of the reporting period. [Refer: Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r19" ] }, "ifrs-full_IncreaseDecreaseInFairValueMeasurementAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseInFairValueMeasurementAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Gains/(losses) recognised in profit or loss/other comprehensive income relating to assets and liabilities held at the end of the period", "label": "Increase (decrease) in fair value measurement, assets" } }, "en": { "role": { "documentation": "The increase (decrease) in the fair value measurement of assets. [Refer: At fair value [member]]" } } }, "auth_ref": [ "r91" ] }, "ifrs-full_IncreaseDecreaseInFairValueMeasurementDueToReasonablyPossibleDecreaseInUnobservableInputAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseInFairValueMeasurementDueToReasonablyPossibleDecreaseInUnobservableInputAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Increase (decrease) in fair value measurement due to reasonably possible decrease in unobservable input, assets", "label": "Increase (decrease) in fair value measurement due to reasonably possible decrease in unobservable input, assets" } }, "en": { "role": { "documentation": "The amount of increase (decrease) in the fair value measurement of assets due to a reasonably possible decrease in an unobservable input." } } }, "auth_ref": [ "r92" ] }, "ifrs-full_IncreaseDecreaseInFairValueMeasurementDueToReasonablyPossibleIncreaseInUnobservableInputAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseInFairValueMeasurementDueToReasonablyPossibleIncreaseInUnobservableInputAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Increase (decrease) in fair value measurement due to reasonably possible increase in unobservable input, assets", "label": "Increase (decrease) in fair value measurement due to reasonably possible increase in unobservable input, assets" } }, "en": { "role": { "documentation": "The amount of increase (decrease) in the fair value measurement of assets due to a reasonably possible increase in an unobservable input." } } }, "auth_ref": [ "r92" ] }, "ifrs-full_IncreaseDecreaseInFairValueMeasurementLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseInFairValueMeasurementLiabilities", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Gains/(losses) recognised in profit or loss/other comprehensive income relating to assets and liabilities held at the end of the year", "label": "Increase (decrease) in fair value measurement, liabilities" } }, "en": { "role": { "documentation": "The increase (decrease) in the fair value measurement of liabilities. [Refer: At fair value [member]]" } } }, "auth_ref": [ "r91" ] }, "san_IncreaseDecreaseInNetInterestIncomeIfAffectedByBasisPointParallelShift": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseInNetInterestIncomeIfAffectedByBasisPointParallelShift", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails" ], "lang": { "en-us": { "role": { "terseLabel": "NII sensitivity (reviewed)", "label": "Increase (Decrease) In Net Interest Income If Affected By Basis Point Parallel Shift", "documentation": "Increase (Decrease) In Net Interest Income If Affected By Basis Point Parallel Shift" } } }, "auth_ref": [] }, "san_IncreaseDecreaseInOperatingExpenses": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseInOperatingExpenses", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Decrease in operating expenses", "label": "Increase (Decrease) In Operating Expenses", "documentation": "Increase (Decrease) In Operating Expenses" } } }, "auth_ref": [] }, "san_IncreaseDecreaseInTotalExpectedCreditLosses": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseInTotalExpectedCreditLosses", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Net movement in the period, ECL", "label": "Increase Decrease In Total Expected Credit Losses", "documentation": "Increase decrease in total expected credit losses." } } }, "auth_ref": [] }, "san_IncreaseDecreaseInTotalFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseInTotalFinancialAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Net movement in the period", "label": "Increase (Decrease) In Total Financial Assets", "documentation": "Increase (decrease) in total financial assets." } } }, "auth_ref": [] }, "san_IncreaseDecreaseThroughAcquisitionOfTSBFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughAcquisitionOfTSBFinancialAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Acquisition of TSB", "label": "Increase (Decrease) Through Acquisition Of TSB, Financial Assets", "documentation": "Increase (Decrease) Through Acquisition Of TSB, Financial Assets" } } }, "auth_ref": [] }, "san_IncreaseDecreaseThroughChangesInEconomicInputs": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughChangesInEconomicInputs", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Change in economic scenarios", "label": "Increase (Decrease) Through Changes In Economic Inputs", "documentation": "Increase decrease through changes in economic inputs." } } }, "auth_ref": [] }, "ifrs-full_IncreaseDecreaseThroughChangesInModelsOrRiskParametersFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseThroughChangesInModelsOrRiskParametersFinancialAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Change to ECL models", "label": "Increase (decrease) through changes in models or risk parameters, financial assets" } }, "en": { "role": { "documentation": "The increase (decrease) in financial assets resulting from changes in models or risk parameters. [Refer: Financial assets]" } } }, "auth_ref": [ "r305", "r313", "r322" ] }, "san_IncreaseDecreaseThroughECLRelatesToDerecognisedIncome": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughECLRelatesToDerecognisedIncome", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Less: Discount unwind", "label": "Increase (Decrease) Through ECL Relates To Derecognised Income", "documentation": "Increase Decrease Through ECL Relates To Derecognised Income." } } }, "auth_ref": [] }, "san_IncreaseDecreaseThroughNetRemeasurementOfECLOnStageTransfer": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughNetRemeasurementOfECLOnStageTransfer", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Net ECL remeasurement on stage transfer", "label": "Increase (Decrease) Through Net Remeasurement Of ECL On Stage Transfer", "documentation": "Increase (decrease) through net remeasurement of ECL on stage transfer." } } }, "auth_ref": [] }, "ifrs-full_IncreaseDecreaseThroughOtherMovementsFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseThroughOtherMovementsFinancialAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Changes in risk parameters and other movements", "label": "Increase (decrease) through other movements, financial assets" } }, "en": { "role": { "documentation": "The increase (decrease) in financial assets resulting from other movements. [Refer: Financial assets]" } } }, "auth_ref": [ "r305", "r309", "r313", "r322", "r326" ] }, "ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesOtherProvisions": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseThroughTransfersAndOtherChangesOtherProvisions", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Reclassification from provisions to other assets", "label": "Increase (decrease) through transfers and other changes, other provisions" } }, "en": { "role": { "documentation": "The increase (decrease) in other provisions resulting from transfers and changes that the entity does not separately disclose in the same statement or note. [Refer: Other provisions]" } } }, "auth_ref": [ "r346" ] }, "ifrs-full_IncreaseDecreaseThroughTransfersFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseDecreaseThroughTransfersFinancialAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers of financial instruments", "label": "Increase (decrease) through transfers, financial assets" } }, "en": { "role": { "documentation": "The increase (decrease) in financial assets resulting from transfers. [Refer: Financial assets]" } } }, "auth_ref": [ "r305", "r308", "r313", "r322", "r325" ] }, "san_IncreaseDecreaseThroughTransfersFromStageOneToStageTwoFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughTransfersFromStageOneToStageTwoFinancialAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers from Stage 1 to Stage 2", "label": "Increase Decrease Through Transfers From Stage One To Stage Two Financial Assets", "documentation": "Increase decrease through transfers from Stage 1 To Stage 2 financial assets" } } }, "auth_ref": [] }, "san_IncreaseDecreaseThroughTransfersFromStageThreeFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughTransfersFromStageThreeFinancialAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers from Stage 3", "label": "Increase Decrease Through Transfers From Stage Three Financial Assets", "documentation": "Increase decrease through transfers from stage 3 financial assets" } } }, "auth_ref": [] }, "san_IncreaseDecreaseThroughTransfersFromStageTwoToStageOneFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughTransfersFromStageTwoToStageOneFinancialAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers from Stage 2 to Stage 1", "label": "Increase Decrease Through Transfers From Stage Two To Stage One Financial Assets", "documentation": "Increase decrease through transfers from stage 2 To stage 1 financial assets" } } }, "auth_ref": [] }, "san_IncreaseDecreaseThroughTransfersToStageThreeFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseDecreaseThroughTransfersToStageThreeFinancialAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers to Stage 3", "label": "Increase Decrease Through Transfers To Stage Three Financial Assets", "documentation": "Increase decrease through transfers to stage 3 financial assets" } } }, "auth_ref": [] }, "san_IncreaseInAssetsRecognisedInEntitysFinancialStatementsInRelationToStructuredEntities": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseInAssetsRecognisedInEntitysFinancialStatementsInRelationToStructuredEntities", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Increase in assets recognised in entity's financial statements in relation to structured entities", "label": "Increase In Assets Recognised In Entity's Financial Statements In Relation To Structured Entities", "documentation": "Increase In Assets Recognised In Entity's Financial Statements In Relation To Structured Entities" } } }, "auth_ref": [] }, "san_IncreaseInNoteIssuancesAvailableForCreatingCollateral": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseInNoteIssuancesAvailableForCreatingCollateral", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Increase in note issuances available for creating collateral", "label": "Increase In Note Issuances Available For Creating Collateral", "documentation": "Increase In Note Issuances Available For Creating Collateral" } } }, "auth_ref": [] }, "san_IncreaseOfOneHundredBasisPointsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IncreaseOfOneHundredBasisPointsMember", "presentation": [ "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails" ], "lang": { "en-us": { "role": { "terseLabel": "+100bps", "label": "Increase Of One Hundred Basis Points [Member]", "documentation": "Increase Of One Hundred Basis Points" } } }, "auth_ref": [] }, "ifrs-full_IncreaseThroughOriginationOrPurchaseFinancialAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IncreaseThroughOriginationOrPurchaseFinancialAssets", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "New lending and assets purchased", "label": "Increase through origination or purchase, financial assets" } }, "en": { "role": { "documentation": "The increase in financial assets resulting from origination or purchase. [Refer: Financial assets]" } } }, "auth_ref": [ "r305", "r306", "r313", "r322", "r323" ] }, "san_InflationRateContractsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "InflationRateContractsMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Inflation rate contracts", "label": "Inflation Rate Contracts [Member]", "documentation": "Inflation Rate Contracts" } } }, "auth_ref": [] }, "ifrs-full_IntangibleAssetsAndGoodwill": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IntangibleAssetsAndGoodwill", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 16.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Intangible assets", "label": "Intangible assets and goodwill" } }, "en": { "role": { "documentation": "The amount of intangible assets and goodwill held by the entity. [Refer: Goodwill; Intangible assets other than goodwill]" } } }, "auth_ref": [ "r364" ] }, "ifrs-full_IntangibleAssetsOtherThanGoodwill": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IntangibleAssetsOtherThanGoodwill", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Intangible assets other than goodwill", "label": "Intangible assets other than goodwill" } }, "en": { "role": { "documentation": "The amount of identifiable non-monetary assets without physical substance. This amount does not include goodwill. [Refer: Goodwill]" } } }, "auth_ref": [ "r46", "r209", "r265" ] }, "san_IntercompanyIncludingJointVenturesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IntercompanyIncludingJointVenturesMember", "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Intercompany balances (including joint ventures)", "label": "Intercompany Including Joint Ventures [Member]", "documentation": "Intercompany Including Joint Ventures" } } }, "auth_ref": [] }, "ifrs-full_InterestExpense": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InterestExpense", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_InterestRevenueExpense", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Interest expense and similar charges", "negatedTerseLabel": "Interest expense and similar charges", "label": "Interest expense" } }, "en": { "role": { "documentation": "The amount of expense arising from interest." } } }, "auth_ref": [ "r82", "r152", "r158" ] }, "ifrs-full_InterestPayable": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InterestPayable", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_DepositsFromCustomers", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Accrued interest", "label": "Interest payable" } }, "en": { "role": { "documentation": "The amount of interest recognised as a liability." } } }, "auth_ref": [ "r361" ] }, "ifrs-full_InterestRateSwapContractMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InterestRateSwapContractMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Interest rate contracts", "label": "Interest rate swap contract [member]" } }, "en": { "role": { "documentation": "This member stands for an interest rate swap contract. [Refer: Swap contract [member]]" } } }, "auth_ref": [ "r361" ] }, "ifrs-full_InterestReceivable": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InterestReceivable", "crdr": "debit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_LoansAndAdvancesToCustomers", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Accrued interest", "label": "Interest receivable" } }, "en": { "role": { "documentation": "The amount of interest recognised as a receivable." } } }, "auth_ref": [ "r361" ] }, "san_InterestRefundCustomerRemediationMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "InterestRefundCustomerRemediationMember", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Interest refund customer remediation", "label": "Interest Refund Customer Remediation [Member]", "documentation": "Interest Refund Customer Remediation" } } }, "auth_ref": [] }, "ifrs-full_InterestRevenueExpense": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InterestRevenueExpense", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "san_NetOperatingIncome", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails": { "parentTag": "san_NetOperatingIncome", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Net interest income", "verboseLabel": "Net interest income", "label": "Interest income (expense)" } } }, "auth_ref": [ "r154", "r158", "r367" ] }, "san_InternalMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "InternalMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Internal", "label": "Internal [member]", "documentation": "Internal." } } }, "auth_ref": [] }, "san_InternallyRetainedMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "InternallyRetainedMember", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Internally retained", "label": "Internally Retained [member]", "documentation": "Internally retained." } } }, "auth_ref": [] }, "ifrs-full_InvestmentProperty": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InvestmentProperty", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Investment property", "label": "Investment property" } }, "en": { "role": { "documentation": "The amount of property (land or a building - or part of a building - or both) held (by the owner or by the lessee as a right-of-use asset) to earn rentals or for capital appreciation or both, rather than for: (a) use in the production or supply of goods or services or for administrative purposes; or (b) sale in the ordinary course of business." } } }, "auth_ref": [ "r51", "r53", "r211", "r213", "r264" ] }, "ifrs-full_InvestmentsAccountedForUsingEquityMethodAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InvestmentsAccountedForUsingEquityMethodAbstract", "lang": { "en-us": { "role": { "terseLabel": "Investments accounted for using equity method [abstract]", "label": "Investments accounted for using equity method [abstract]" } } }, "auth_ref": [] }, "ifrs-full_InvestmentsInJointVenturesAccountedForUsingEquityMethod": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "InvestmentsInJointVenturesAccountedForUsingEquityMethod", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 9.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Interests in other entities", "label": "Investments in joint ventures accounted for using equity method" } }, "en": { "role": { "documentation": "The amount of investments in joint ventures accounted for using the equity method. [Refer: Total for all joint ventures [member]; Investments accounted for using equity method]" } } }, "auth_ref": [ "r364" ] }, "san_IssuancesAndRedemptionsOfSecuritisationAndCoveredBondLineItems": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IssuancesAndRedemptionsOfSecuritisationAndCoveredBondLineItems", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Issuances And Redemptions Of Securitisation And Covered Bond [Line items]", "label": "Issuances And Redemptions Of Securitisation And Covered Bond [Line items]", "documentation": "Issuances and redemptions of securitisation and covered bonds." } } }, "auth_ref": [] }, "san_IssuancesAndRedemptionsOfSecuritisationAndCoveredBondTable": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IssuancesAndRedemptionsOfSecuritisationAndCoveredBondTable", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Issuances And Redemptions Of Securitisation And Covered Bond [Table]", "label": "Issuances And Redemptions Of Securitisation And Covered Bond [table]", "documentation": "Issuances and redemption of securitisation and covered bonds." } } }, "auth_ref": [] }, "ifrs-full_IssueOfEquity": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IssueOfEquity", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Issue of other equity instruments", "label": "Issue of equity" } }, "en": { "role": { "documentation": "The increase in equity through the issue of equity instruments." } } }, "auth_ref": [ "r260" ] }, "san_IssueOfOrdinaryShares": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "IssueOfOrdinaryShares", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Issue of ordinary shares", "label": "Issue Of Ordinary Shares", "documentation": "Issue Of Ordinary Shares" } } }, "auth_ref": [] }, "ifrs-full_IssuedCapital": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IssuedCapital", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Equity", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "verboseLabel": "Share capital", "label": "Issued capital" } }, "en": { "role": { "documentation": "The nominal value of capital issued." } } }, "auth_ref": [ "r328", "r333" ] }, "ifrs-full_IssuedCapitalMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IssuedCapitalMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Share capital", "label": "Issued capital [member]" } }, "en": { "role": { "documentation": "This member stands for a component of equity representing issued capital." } } }, "auth_ref": [ "r261" ] }, "ifrs-full_IssuedCapitalPreferenceShares": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "IssuedCapitalPreferenceShares", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails": { "parentTag": "ifrs-full_SubordinatedLiabilities", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "\u00a3325m Sterling preference shares", "label": "Issued capital, preference shares" } }, "en": { "role": { "documentation": "The nominal value of capital arising from issuing preference shares. [Refer: Issued capital]" } } }, "auth_ref": [ "r365" ] }, "san_ItemsInCourseOfTransmissionMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ItemsInCourseOfTransmissionMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Items in the course of transmission", "label": "Items In Course Of Transmission [Member]", "documentation": "Items in course of transmission [member]" } } }, "auth_ref": [] }, "san_KeyAssumptionAppliedAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "KeyAssumptionAppliedAxis", "presentation": [ "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Key Assumption Applied [Axis]", "label": "Key Assumption Applied [Axis]", "documentation": "Key Assumption Applied" } } }, "auth_ref": [] }, "san_KeyAssumptionAppliedDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "KeyAssumptionAppliedDomain", "presentation": [ "http://santander.co.uk/role/MarketRiskYieldCurveRiskDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Key Assumption Applied [Domain]", "label": "Key Assumption Applied [Domain]", "documentation": "Key Assumption Applied [Domain]" } } }, "auth_ref": [] }, "ifrs-full_LandAndBuildingsMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LandAndBuildingsMember", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Property", "label": "Land and buildings [member]" } }, "en": { "role": { "documentation": "This member stands for a class of property, plant and equipment representing land and depreciable buildings and similar structures for use in operations. [Refer: Buildings; Land; Property, plant and equipment]" } } }, "auth_ref": [ "r282" ] }, "ifrs-full_LegalProceedingsProvisionMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LegalProceedingsProvisionMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Litigation and other regulatory", "label": "Legal proceedings provision [member]" } }, "en": { "role": { "documentation": "This member stands for a provision for legal proceedings. [Refer: Classes of other provisions [domain]]" } } }, "auth_ref": [ "r287", "r288" ] }, "ifrs-full_Level1OfFairValueHierarchyMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Level1OfFairValueHierarchyMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Level 1", "label": "Level 1 of fair value hierarchy [member]" } }, "en": { "role": { "documentation": "This member stands for a category of the fair value hierarchy where inputs to the valuation techniques are quoted prices (unadjusted) in active markets for identical assets or liabilities that the entity can access at the measurement date." } } }, "auth_ref": [ "r18", "r33", "r35", "r86", "r199", "r247" ] }, "ifrs-full_Level2OfFairValueHierarchyMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Level2OfFairValueHierarchyMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Level 2", "label": "Level 2 of fair value hierarchy [member]" } }, "en": { "role": { "documentation": "This member stands for a category of the fair value hierarchy where inputs to the valuation techniques are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly." } } }, "auth_ref": [ "r33", "r35", "r86", "r199", "r247" ] }, "ifrs-full_Level3OfFairValueHierarchyMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Level3OfFairValueHierarchyMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Level 3", "label": "Level 3 of fair value hierarchy [member]" } }, "en": { "role": { "documentation": "This member stands for a category of the fair value hierarchy where inputs to the valuation techniques are unobservable inputs for the asset or liability. Unobservable inputs are inputs for which market data are not available and that are developed using the best information available about the assumptions that the market participants would use when pricing the asset or liability." } } }, "auth_ref": [ "r33", "r35", "r86", "r199", "r247" ] }, "ifrs-full_LevelsOfFairValueHierarchyAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LevelsOfFairValueHierarchyAxis", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Levels of fair value hierarchy [axis]", "label": "Levels of fair value hierarchy [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r18", "r86", "r247" ] }, "ifrs-full_LevelsOfFairValueHierarchyDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LevelsOfFairValueHierarchyDomain", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Levels of fair value hierarchy [domain]", "label": "Levels of fair value hierarchy [domain]" } }, "en": { "role": { "documentation": "This member stands for all levels of the fair value hierarchy. It also represents the standard value for the 'Levels of fair value hierarchy' axis if no other member is used." } } }, "auth_ref": [ "r18", "r86", "r247" ] }, "ifrs-full_Liabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Liabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_EquityAndLiabilities", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Total liabilities", "negatedPeriodStartLabel": "Beginning balance", "negatedPeriodEndLabel": "Ending Balance", "label": "Liabilities" } }, "en": { "role": { "documentation": "The amount of a present obligation of the entity to transfer an economic resource as a result of past events. Economic resource is a right that has the potential to produce economic benefits." } } }, "auth_ref": [ "r85", "r86", "r91", "r154", "r157", "r246", "r247", "r269" ] }, "ifrs-full_LiabilitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LiabilitiesAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Liabilities", "label": "Liabilities [abstract]" } } }, "auth_ref": [] }, "ifrs-full_LiabilityAssetOfDefinedBenefitPlans": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LiabilityAssetOfDefinedBenefitPlans", "crdr": "credit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofNetAssetsRecognisedDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofNetAssetsRecognisedDetails", "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Total net assets", "negatedTotalLabel": "Net defined benefit assets", "label": "Net defined benefit liability (asset)" } }, "en": { "role": { "documentation": "The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]]" } } }, "auth_ref": [ "r13", "r190" ] }, "ifrs-full_LifetimeExpectedCreditLossesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LifetimeExpectedCreditLossesMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Subject to Lifetime ECL", "label": "Lifetime expected credit losses [member]" } }, "en": { "role": { "documentation": "This member stands for the expected credit losses that result from all possible default events over the expected life of a financial instrument. [Refer: Type of measurement of expected credit losses [domain]]" } } }, "auth_ref": [ "r129", "r135", "r235", "r241" ] }, "san_LitigationAndOtherRegulatoryMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LitigationAndOtherRegulatoryMember", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Litigation and other regulatory", "label": "Litigation And Other Regulatory [Member]", "documentation": "Litigation And Other Regulatory" } } }, "auth_ref": [] }, "san_LitigationSettlementMaximumPotentialExposure": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LitigationSettlementMaximumPotentialExposure", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Litigation settlement, maximum potential exposure", "label": "Litigation Settlement, Maximum Potential Exposure", "documentation": "Litigation Settlement, Maximum Potential Exposure" } } }, "auth_ref": [] }, "ifrs-full_LoanCommitmentsMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LoanCommitmentsMember", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Formal standby facilities, credit lines and other commitments", "label": "Loan commitments [member]" } }, "en": { "role": { "documentation": "This member stands for firm commitments to provide credit under pre-specified terms and conditions." } } }, "auth_ref": [ "r137", "r148", "r238", "r243" ] }, "ifrs-full_LoansAndAdvancesToBanks": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LoansAndAdvancesToBanks", "crdr": "debit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialAssets", "weight": 1.0, "order": 3.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 11.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Loans and advances to banks", "label": "Loans and advances to banks" } }, "en": { "role": { "documentation": "The amount of loans and advances the entity has made to banks." } } }, "auth_ref": [ "r364" ] }, "san_LoansAndAdvancesToBanksMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LoansAndAdvancesToBanksMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Loans and advances to banks", "label": "Loans And Advances To Banks [Member]", "documentation": "Loans and advances to banks." } } }, "auth_ref": [] }, "san_LoansAndAdvancesToBanksRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LoansAndAdvancesToBanksRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Loans and advances to banks", "label": "Loans And Advances To Banks Recognised As Of Acquisition Date", "documentation": "Loans And Advances To Banks Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "ifrs-full_LoansAndAdvancesToCustomers": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LoansAndAdvancesToCustomers", "crdr": "debit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialAssets", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 4.0 }, "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails", "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Loans and advances to customers", "verboseLabel": "Exposure", "totalLabel": "Net loans and advances to customers", "label": "Loans and advances to customers" } }, "en": { "role": { "documentation": "The amount of loans and advances the entity has made to customers." } } }, "auth_ref": [ "r364" ] }, "san_LoansAndAdvancesToCustomersExcludingIntercompanyBalancesGross": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LoansAndAdvancesToCustomersExcludingIntercompanyBalancesGross", "crdr": "debit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "san_LoansAndAdvancesToCustomersNet", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Customer balances (gross)", "label": "Loans And Advances To Customers Excluding Intercompany Balances, Gross", "documentation": "Loans And Advances To Customers Excluding Intercompany Balances, Gross" } } }, "auth_ref": [] }, "san_LoansAndAdvancesToCustomersForResidentialMortgages": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LoansAndAdvancesToCustomersForResidentialMortgages", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Exposure - of which: mortgages", "label": "Loans And Advances To Customers For Residential Mortgages", "documentation": "Loans and advances to customers for residential mortgages." } } }, "auth_ref": [] }, "san_LoansAndAdvancesToCustomersMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LoansAndAdvancesToCustomersMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Loans and advances to customers:", "label": "Loans And Advances To Customers [Member]", "documentation": "Loans and advances to customers, netting." } } }, "auth_ref": [] }, "san_LoansAndAdvancesToCustomersNet": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LoansAndAdvancesToCustomersNet", "crdr": "debit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_LoansAndAdvancesToCustomers", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Customer balances (net)", "label": "Loans And Advances To Customers, Net", "documentation": "Loans And Advances To Customers, Net" } } }, "auth_ref": [] }, "san_LoansAndAdvancesToCustomersRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LoansAndAdvancesToCustomersRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Loans and advances to customers", "label": "Loans And Advances To Customers Recognised As Of Acquisition Date", "documentation": "Loans And Advances To Customers Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_LongevityAtSixtyForCurrentPensionersOnValuationDateAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LongevityAtSixtyForCurrentPensionersOnValuationDateAbstract", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Longevity at 60 for current pensioners, on the valuation date:", "label": "Longevity At Sixty For Current Pensioners, On Valuation Date [Abstract]", "documentation": "Longevity at sixty for current pensioners, on valuation date." } } }, "auth_ref": [] }, "san_LongevityAtSixtyForFuturePensionersCurrentlyAgedFortyOnValuationDateAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LongevityAtSixtyForFuturePensionersCurrentlyAgedFortyOnValuationDateAbstract", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Longevity at 60 for future pensioners currently aged 40, on the valuation date:", "label": "Longevity At Sixty For Future Pensioners Currently Aged Forty, On Valuation Date [Abstract]", "documentation": "Longevity at sixty for future pensioners currently aged forty, on valuation date." } } }, "auth_ref": [] }, "san_LongevityForCurrentPensionersFemalesOne": { "xbrltype": "durationItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LongevityForCurrentPensionersFemalesOne", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Females", "label": "Longevity For Current Pensioners Females One", "documentation": "Longevity for current pensioners females one." } } }, "auth_ref": [] }, "san_LongevityForCurrentPensionersMalesOne": { "xbrltype": "durationItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LongevityForCurrentPensionersMalesOne", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Males", "label": "Longevity For Current Pensioners Males One", "documentation": "Longevity for current pensioners males one." } } }, "auth_ref": [] }, "san_LongevityForFuturePensionersFemalesOne": { "xbrltype": "durationItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LongevityForFuturePensionersFemalesOne", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Females", "label": "Longevity For Future Pensioners Females One", "documentation": "Longevity For Future Pensioners Females One" } } }, "auth_ref": [] }, "san_LongevityForFuturePensionersMalesOne": { "xbrltype": "durationItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "LongevityForFuturePensionersMalesOne", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofPrincipalActuarialAssumptionsUsedforDefinedBenefitSchemesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Males", "label": "Longevity For Future Pensioners Males One", "documentation": "Longevity For Future Pensioners Males One" } } }, "auth_ref": [] }, "ifrs-full_LossesOnLitigationSettlements": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "LossesOnLitigationSettlements", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Losses on litigation settlements", "label": "Losses on litigation settlements" } } }, "auth_ref": [ "r280" ] }, "san_MacroHedgeOfInterestRateRiskAsset": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MacroHedgeOfInterestRateRiskAsset", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Macro hedge of interest rate risk", "label": "Macro Hedge Of Interest Rate Risk, Asset", "documentation": "Macro Hedge Of Interest Rate Risk, Asset" } } }, "auth_ref": [] }, "san_MacroHedgeOfInterestRateRiskLiability": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MacroHedgeOfInterestRateRiskLiability", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 7.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Macro hedge of interest rate risk", "label": "Macro Hedge Of Interest Rate Risk, Liability", "documentation": "Macro Hedge Of Interest Rate Risk, Liability" } } }, "auth_ref": [] }, "ifrs-full_MajorComponentsOfTaxExpenseIncomeAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "MajorComponentsOfTaxExpenseIncomeAbstract", "lang": { "en-us": { "role": { "terseLabel": "Major components of tax expense (income) [abstract]", "label": "Major components of tax expense (income) [abstract]" } } }, "auth_ref": [] }, "ifrs-full_MandatoryReserveDepositsAtCentralBanks": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "MandatoryReserveDepositsAtCentralBanks", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashAndBankBalancesAtCentralBanks", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Less: restricted balances", "label": "Mandatory reserve deposits at central banks" } }, "en": { "role": { "documentation": "The amount of reserve that is kept in deposit at a central bank to fulfil regulatory reserve requirements." } } }, "auth_ref": [ "r361" ] }, "san_MasterTrustStructuresMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MasterTrustStructuresMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Mortgage-backed master trust structures:", "label": "Master Trust Structures [member]", "documentation": "Master trust structures." } } }, "auth_ref": [] }, "ifrs-full_MeasurementAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "MeasurementAxis", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Measurement [axis]", "label": "Measurement [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r50", "r54", "r85", "r214", "r246" ] }, "ifrs-full_MeasurementDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "MeasurementDomain", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Measurement [domain]", "label": "Measurement [domain]" } }, "en": { "role": { "documentation": "This member stands for all types of measurement. It also represents the standard value for the 'Measurement' axis if no other member is used." } } }, "auth_ref": [ "r50", "r54", "r85", "r214", "r246" ] }, "san_MediumTermNotesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MediumTermNotesMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Medium-term notes", "label": "Medium-Term Notes [Member]", "documentation": "Medium Term Notes" } } }, "auth_ref": [] }, "ifrs-full_MethodOfAssessmentOfExpectedCreditLossesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "MethodOfAssessmentOfExpectedCreditLossesAxis", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Method of assessment of expected credit losses [axis]", "label": "Method of assessment of expected credit losses [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r305", "r309", "r313", "r322", "r326" ] }, "ifrs-full_MethodOfAssessmentOfExpectedCreditLossesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "MethodOfAssessmentOfExpectedCreditLossesDomain", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Method of assessment of expected credit losses [domain]", "label": "Method of assessment of expected credit losses [domain]" } }, "en": { "role": { "documentation": "This member stands for all methods of assessment of expected credit losses. Expected credit losses are the weighted average of credit losses with the respective risks of a default occurring as the weights. This member also represents the standard value for the 'Method of assessment of expected credit losses' axis if no other member is used." } } }, "auth_ref": [ "r305", "r309", "r313", "r322", "r326" ] }, "san_MortgageBackedNotesIssued": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MortgageBackedNotesIssued", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Internal and external issuances", "label": "Mortgage Backed Notes Issued", "documentation": "Mortgage backed notes issued." } } }, "auth_ref": [] }, "san_MortgageBackedNotesSold": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MortgageBackedNotesSold", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Mortgage backed notes sold", "label": "Mortgage Backed Notes Sold", "documentation": "Mortgage Backed Notes Sold" } } }, "auth_ref": [] }, "san_MortgageBackedSecuritiesRedeemed": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MortgageBackedSecuritiesRedeemed", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Internal and external redemptions", "label": "Mortgage Backed Securities Redeemed", "documentation": "Mortgage backed securities redeemed." } } }, "auth_ref": [] }, "san_MortgageFairValueImpactMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "MortgageFairValueImpactMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Impact on mortgage fair value", "label": "Mortgage Fair Value Impact [Member]", "documentation": "Mortgage Fair Value Impact" } } }, "auth_ref": [] }, "ifrs-full_MortgageLoans": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "MortgageLoans", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Mortgage loans", "label": "Mortgage loans" } }, "en": { "role": { "documentation": "The amount of mortgage loans made by the entity." } } }, "auth_ref": [ "r364" ] }, "ifrs-full_NetAssetsLiabilitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NetAssetsLiabilitiesAbstract", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Net assets (liabilities) [abstract]", "label": "Net assets (liabilities) [abstract]" } } }, "auth_ref": [] }, "san_NetCashFlowFromAcquisition": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NetCashFlowFromAcquisition", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails" ], "lang": { "en-us": { "role": { "negatedTotalLabel": "Net cash flow from acquisition of TSB", "label": "Net Cash Flow From Acquisition", "documentation": "Net Cash Flow From Acquisition" } } }, "auth_ref": [] }, "ifrs-full_NetDeferredTaxLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NetDeferredTaxLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Deferred tax liabilities", "label": "Net deferred tax liabilities" } }, "en": { "role": { "documentation": "The amount of deferred tax liabilities net of deferred tax assets, when the absolute amount of deferred tax liabilities is greater than the absolute amount of deferred tax assets. [Refer: Deferred tax assets; Deferred tax liabilities]" } } }, "auth_ref": [ "r337" ] }, "ifrs-full_NetDefinedBenefitLiabilityAssetAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NetDefinedBenefitLiabilityAssetAxis", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Net defined benefit liability (asset) [axis]", "label": "Net defined benefit liability (asset) [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r13", "r190" ] }, "ifrs-full_NetDefinedBenefitLiabilityAssetDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NetDefinedBenefitLiabilityAssetDomain", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Net defined benefit liability (asset) [domain]", "label": "Net defined benefit liability (asset) [domain]" } }, "en": { "role": { "documentation": "This member stands for the net defined benefit liability (asset). It also represents the standard value for the 'Net defined benefit liability (asset)' axis if no other member is used. [Refer: Net defined benefit liability (asset)]" } } }, "auth_ref": [ "r13", "r190" ] }, "san_NetLoansAndAdvancesToCustomersAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NetLoansAndAdvancesToCustomersAbstract", "lang": { "en-us": { "role": { "terseLabel": "Net Loans and Advances to Customers [abstract]", "label": "Net Loans And Advances To Customers [Abstract]", "documentation": "Net loans and advances to customers [abstract]." } } }, "auth_ref": [] }, "san_NetOperatingIncome": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NetOperatingIncome", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_ProfitLossBeforeTax", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Net operating income", "label": "Net Operating Income", "documentation": "Net Operating Income" } } }, "auth_ref": [] }, "san_NettingAdjustmentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NettingAdjustmentsMember", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Derivative netting", "label": "Netting Adjustments [member]", "documentation": "Netting adjustments." } } }, "auth_ref": [] }, "san_NettingContractsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NettingContractsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Netting", "label": "Netting Contracts [Member]", "documentation": "Netting contracts." } } }, "auth_ref": [] }, "san_NonInterestIncomeExpense": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NonInterestIncomeExpense", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails": { "parentTag": "san_NetOperatingIncome", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Non-interest income/(expense)", "label": "Non Interest Income (Expense)", "documentation": "Non interest income expense." } } }, "auth_ref": [] }, "ifrs-full_NonadjustingEventsAfterReportingPeriodAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NonadjustingEventsAfterReportingPeriodAxis", "presentation": [ "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Non-adjusting events after reporting period [axis]", "label": "Non-adjusting events after reporting period [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r0", "r181" ] }, "ifrs-full_NonadjustingEventsAfterReportingPeriodDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NonadjustingEventsAfterReportingPeriodDomain", "presentation": [ "http://santander.co.uk/role/EVENTSAFTERTHEBALANCESHEETDATEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Non-adjusting events after reporting period [member]", "label": "Non-adjusting events after reporting period [domain]" } }, "en": { "role": { "documentation": "This member stands for events that occur between the end of the reporting period and the date when the financial statements are authorised for issue and are indicative of conditions that arose after the reporting period. It also represents the standard value for the 'Non-adjusting events after reporting period' axis if no other member is used." } } }, "auth_ref": [ "r0", "r181" ] }, "ifrs-full_NoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSale": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSale", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 14.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Assets held for sale", "label": "Non-current assets or disposal groups classified as held for sale" } }, "en": { "role": { "documentation": "The amount of non-current assets or disposal groups classified as held for sale. [Refer: Disposal groups classified as held for sale [member]]" } } }, "auth_ref": [ "r121" ] }, "san_NoteIssuancesAvailableForCreatingCollateral": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NoteIssuancesAvailableForCreatingCollateral", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Internally retained securitisation and covered bond issuances available for creating collateral", "label": "Note Issuances Available For Creating Collateral", "documentation": "Note issuances available for creating collateral." } } }, "auth_ref": [] }, "ifrs-full_NotesAndDebenturesIssued": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NotesAndDebenturesIssued", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Notes issued under securitisation and covered bond programmes retained internally", "label": "Notes and debentures issued" } }, "en": { "role": { "documentation": "The amount of notes and debentures issued by the entity." } } }, "auth_ref": [ "r361" ] }, "ifrs-full_NotionalAmount": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "NotionalAmount", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Notional amount", "label": "Notional amount" } }, "en": { "role": { "documentation": "The nominal or face amount of a financial instrument, used to calculate payments made on that instrument." } } }, "auth_ref": [ "r361" ] }, "san_NumberOfBranchClosures": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfBranchClosures", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of branch closures", "label": "Number of Branch Closures", "documentation": "Number of Branch Closures" } } }, "auth_ref": [] }, "san_NumberOfBranches": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfBranches", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of branches", "label": "Number Of Branches", "documentation": "Number Of Branches" } } }, "auth_ref": [] }, "san_NumberOfEmployeesAtRiskForRedundancy": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfEmployeesAtRiskForRedundancy", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of employees at risk for redundancy", "label": "Number Of Employees At Risk For Redundancy", "documentation": "Number Of Employees At Risk For Redundancy" } } }, "auth_ref": [] }, "san_NumberOfSantanderLocals": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfSantanderLocals", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of santander locals", "label": "Number Of Santander Locals", "documentation": "Number Of Santander Locals" } } }, "auth_ref": [] }, "san_NumberOfSegments": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfSegments", "presentation": [ "http://santander.co.uk/role/SEGMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of segments", "label": "Number Of Segments", "documentation": "Number Of Segments" } } }, "auth_ref": [] }, "san_NumberOfStructuredEntities": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfStructuredEntities", "presentation": [ "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of structured entities", "label": "Number Of Structured Entities", "documentation": "Number Of Structured Entities" } } }, "auth_ref": [] }, "san_NumberOfSubsidiaries": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfSubsidiaries", "presentation": [ "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of subsidiaries", "label": "Number Of Subsidiaries", "documentation": "Number Of Subsidiaries" } } }, "auth_ref": [] }, "san_NumberOfWorkCafesWithSupportProvided": { "xbrltype": "integerItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "NumberOfWorkCafesWithSupportProvided", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Number of work cafes with support provided", "label": "Number Of Work Cafes With Support Provided", "documentation": "Number Of Work Cafes With Support Provided" } } }, "auth_ref": [] }, "san_OffBalanceSheetCreditExposures": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OffBalanceSheetCreditExposures", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails": { "parentTag": "ifrs-full_ImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESSummaryofImpairmentLossesandProvisionsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Off-balance sheet credit exposures (See Note 21)", "label": "Off-Balance Sheet Credit Exposures", "documentation": "Off balance sheet credit exposures." } } }, "auth_ref": [] }, "ifrs-full_OfficeEquipmentMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OfficeEquipmentMember", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Office fixtures and equipment", "label": "Office equipment [member]" } }, "en": { "role": { "documentation": "This member stands for a class of property, plant and equipment representing equipment used to support office functions, not specifically used in the production process. [Refer: Property, plant and equipment]" } } }, "auth_ref": [ "r283" ] }, "san_OperatingExpensesBeforeCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OperatingExpensesBeforeCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_ProfitLossBeforeTax", "weight": -1.0, "order": 2.0 }, "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Operating expenses before credit impairment charges, restructuring and specific provisions", "negatedTerseLabel": "Operating expenses before credit impairment charges, restructuring and specific provisions", "totalLabel": "Total operating expenses before impairment losses, provisions and charges", "label": "Operating Expenses Before Credit Impairment (Charges)/Write-Backs, Restructuring And Specific Provisions", "documentation": "Operating Expenses Before Credit Impairment (Charges)/Write-Backs, Restructuring And Specific Provisions" } } }, "auth_ref": [] }, "san_OperationalLosses": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OperationalLosses", "crdr": "debit", "calculation": { "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails": { "parentTag": "san_OperatingExpensesBeforeCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Operational losses", "label": "Operational Losses", "documentation": "Operational Losses" } } }, "auth_ref": [] }, "san_OperationalRiskProvisionsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OperationalRiskProvisionsMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Operational risk provisions", "label": "Operational Risk Provisions [Member]", "documentation": "Operational Risk Provisions" } } }, "auth_ref": [] }, "san_OtherAdministrationExpenses": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherAdministrationExpenses", "crdr": "debit", "calculation": { "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails": { "parentTag": "san_OperatingExpensesBeforeCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/OPERATINGEXPENSESBEFORECREDITIMPAIRMENTCHARGESRESTRUCTURINGANDSPECIFICPROVISIONSSummaryofOperatingExpensesBeforeCreditImpairmentLossesProvisionsandChargesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other administration expenses", "label": "Other Administration Expenses", "documentation": "Total other administration expenses." } } }, "auth_ref": [] }, "ifrs-full_OtherAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherAssets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other assets", "label": "Other assets" } }, "en": { "role": { "documentation": "The amount of assets that the entity does not separately disclose in the same statement or note." } } }, "auth_ref": [ "r364" ] }, "san_OtherAssetsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherAssetsRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 11.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other assets", "label": "Other Assets Recognised As Of Acquisition Date", "documentation": "Other Assets Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_OtherCashEquivalentsLoansAndAdvancesToBanksNonTrading": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherCashEquivalentsLoansAndAdvancesToBanksNonTrading", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashAndCashEquivalents", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other cash equivalents: Loans and advances to banks - non-trading", "label": "Other Cash Equivalents, Loans And Advances To Banks - Non Trading", "documentation": "Other Cash Equivalents, Loans And Advances To Banks - Non Trading" } } }, "auth_ref": [] }, "ifrs-full_OtherComprehensiveIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncome", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_ComprehensiveIncome", "weight": 1.0, "order": 2.0 }, "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Total other comprehensive (expense)/income net of tax", "label": "Other comprehensive income" } } }, "auth_ref": [ "r79", "r259", "r273", "r277" ] }, "ifrs-full_OtherComprehensiveIncomeAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "verboseLabel": "Other comprehensive income:", "terseLabel": "Other comprehensive income, net of tax:", "label": "Other comprehensive income [abstract]" } } }, "auth_ref": [] }, "ifrs-full_OtherComprehensiveIncomeBeforeTaxChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiability": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeBeforeTaxChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiability", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiability", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "- Change in fair value", "label": "Other comprehensive income, before tax, change in fair value of financial liability attributable to change in credit risk of liability" } }, "en": { "role": { "documentation": "The amount of other comprehensive income, before tax, related to change in the fair value of financial liability attributable to change in the credit risk of the liability. [Refer: Other comprehensive income, before tax; Credit risk [member]]" } } }, "auth_ref": [ "r270", "r278" ] }, "ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "- Remeasurements of the net defined benefit (asset)/liability", "label": "Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans" } }, "en": { "role": { "documentation": "The amount of other comprehensive income, before tax, related to gains (losses) on remeasurements of defined benefit plans, which comprise actuarial gains and losses; the return on plan assets, excluding amounts included in net interest on the net defined benefit liability (asset); and any change in the effect of the asset ceiling, excluding amounts included in net interest on the net defined benefit liability (asset). [Refer: Other comprehensive income; Defined benefit plans [domain]; Plan assets [member]; Net defined benefit liability (asset)] [Contrast: Decrease (increase) in net defined benefit liability (asset) resulting from gain (loss) on remeasurement in other comprehensive income]" } } }, "auth_ref": [ "r270", "r278", "r340" ] }, "ifrs-full_OtherComprehensiveIncomeNetOfTaxCashFlowHedges": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeNetOfTaxCashFlowHedges", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax", "weight": 1.0, "order": 2.0 }, "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncome", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Other comprehensive income, cash flow hedges, total", "terseLabel": "- Cash flow hedges", "label": "Other comprehensive income, net of tax, cash flow hedges" } }, "en": { "role": { "documentation": "The amount of other comprehensive income, net of tax, after reclassification adjustments, related to cash flow hedges. [Refer: Cash flow hedges [member]; Other comprehensive income]" } } }, "auth_ref": [ "r270", "r277" ] }, "ifrs-full_OtherComprehensiveIncomeNetOfTaxChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiability": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeNetOfTaxChangeInFairValueOfFinancialLiabilityAttributableToChangeInCreditRiskOfLiability", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax", "weight": 1.0, "order": 2.0 }, "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncome", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Own credit adjustment, total", "terseLabel": "- Own credit adjustment", "label": "Other comprehensive income, net of tax, change in fair value of financial liability attributable to change in credit risk of liability" } }, "en": { "role": { "documentation": "The amount of other comprehensive income, net of tax, related to changes in the fair value of financial liabilities attributable to the changes in the credit risk of those liabilities. [Refer: Other comprehensive income; Credit risk [member]; Financial liabilities]" } } }, "auth_ref": [ "r270", "r277" ] }, "ifrs-full_OtherComprehensiveIncomeNetOfTaxChangeInValueOfTimeValueOfOptions": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeNetOfTaxChangeInValueOfTimeValueOfOptions", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax", "weight": 1.0, "order": 3.0 }, "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncome", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Other comprehensive income, net of tax, change in value of time value of options", "terseLabel": "- Cost of hedging", "label": "Other comprehensive income, net of tax, change in value of time value of options" } }, "en": { "role": { "documentation": "The amount of other comprehensive income, net of tax, after reclassification adjustments, related to change in value of time value of options. [Refer: Other comprehensive income]" } } }, "auth_ref": [ "r270", "r277" ] }, "ifrs-full_OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncome", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Pension remeasurement, total", "terseLabel": "- Pension remeasurement", "label": "Other comprehensive income, net of tax, gains (losses) on remeasurements of defined benefit plans" } }, "en": { "role": { "documentation": "The amount of other comprehensive income, net of tax, related to gains (losses) on remeasurements of defined benefit plans, which comprise actuarial gains and losses; the return on plan assets, excluding amounts included in net interest on the net defined benefit liability (asset); and any change in the effect of the asset ceiling, excluding amounts included in net interest on the net defined benefit liability (asset). [Refer: Other comprehensive income; Defined benefit plans [domain]; Plan assets [member]; Net defined benefit liability (asset)] [Contrast: Decrease (increase) in net defined benefit liability (asset) resulting from gain (loss) on remeasurement in other comprehensive income]" } } }, "auth_ref": [ "r270", "r277", "r340" ] }, "ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncome", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Net other comprehensive (expense)/income that may be reclassified to profit or loss subsequently", "label": "Other comprehensive income that will be reclassified to profit or loss, net of tax" } }, "en": { "role": { "documentation": "The amount of other comprehensive income that will be reclassified to profit or loss, net of tax. [Refer: Other comprehensive income]" } } }, "auth_ref": [ "r334", "r335" ] }, "ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncome", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Net other comprehensive (expense)/income that will not be reclassified to profit or loss subsequently", "label": "Other comprehensive income that will not be reclassified to profit or loss, net of tax" } }, "en": { "role": { "documentation": "The amount of other comprehensive income that will not be reclassified to profit or loss, net of tax. [Refer: Other comprehensive income]" } } }, "auth_ref": [ "r334", "r335" ] }, "ifrs-full_OtherCurrentReceivables": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherCurrentReceivables", "crdr": "debit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_LoansAndAdvancesToCustomers", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other items", "label": "Other current receivables" } }, "en": { "role": { "documentation": "The amount of current other receivables. [Refer: Other receivables]" } } }, "auth_ref": [ "r327", "r332" ] }, "san_OtherDebtInstrumentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherDebtInstrumentsMember", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other debt instruments", "label": "Other Debt Instruments [Member]", "documentation": "Other Debt Instruments" } } }, "auth_ref": [] }, "san_OtherDepositsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherDepositsMember", "presentation": [ "http://santander.co.uk/role/DEPOSITSBYBANKSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other deposits", "label": "Other Deposits [member]", "documentation": "Other deposits." } } }, "auth_ref": [] }, "ifrs-full_OtherEquityInterest": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherEquityInterest", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Equity", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Other equity instruments", "terseLabel": "Other equity interest", "label": "Other equity interest" } }, "en": { "role": { "documentation": "The amount of equity interest of an entity without share capital that the entity does not separately disclose in the same statement or note." } } }, "auth_ref": [ "r328", "r333" ] }, "ifrs-full_OtherEquityInterestMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherEquityInterestMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other equity instruments", "label": "Other equity interest [member]" } }, "en": { "role": { "documentation": "This member stands for equity interest of an entity without share capital that the entity does not separately disclose in the same statement or note." } } }, "auth_ref": [ "r261" ] }, "san_OtherFinancialAssets1Member": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialAssets1Member", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALASSETSATAMORTISEDCOSTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial assets", "label": "Other Financial Assets1 [Member]", "documentation": "Other financial assets 1" } } }, "auth_ref": [] }, "san_OtherFinancialAssetsAtAmortisedCost": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialAssetsAtAmortisedCost", "crdr": "debit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialAssets", "weight": 1.0, "order": 2.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 8.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial assets at amortised cost", "label": "Other Financial Assets At Amortised Cost", "documentation": "Other financial assets at amortised cost." } } }, "auth_ref": [] }, "san_OtherFinancialAssetsAtAmortisedCostMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialAssetsAtAmortisedCostMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial assets at amortised cost", "label": "Other Financial Assets At Amortised Cost [Member]", "documentation": "Other financial assets at amortised cost." } } }, "auth_ref": [] }, "san_OtherFinancialAssetsAtAmortisedCostRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialAssetsAtAmortisedCostRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial assets at amortised cost", "label": "Other Financial Assets At Amortised Cost Recognised As Of Acquisition Date", "documentation": "Other Financial Assets At Amortised Cost Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_OtherFinancialAssetsAtFairValueThroughProfitOrLoss": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialAssetsAtFairValueThroughProfitOrLoss", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 7.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "verboseLabel": "Other financial assets at fair value through profit or loss", "label": "Other Financial Assets At Fair Value Through Profit Or Loss", "documentation": "Other financial assets at fair value through profit or loss." } } }, "auth_ref": [] }, "san_OtherFinancialAssetsAtFairValueThroughProfitOrLossCategoryMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialAssetsAtFairValueThroughProfitOrLossCategoryMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial assets at FVTPL", "label": "Other Financial Assets At Fair Value Through Profit Or Loss, Category [Member]", "documentation": "Other Financial assets at fair value through profit or loss, category [member]" } } }, "auth_ref": [] }, "san_OtherFinancialLiabilitiesAtFairValueThroughProfitOrLoss": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialLiabilitiesAtFairValueThroughProfitOrLoss", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial liabilities at fair value through profit or loss", "label": "Other Financial Liabilities At Fair Value Through Profit Or Loss", "documentation": "Other financial liabilities at fair value through profit or loss." } } }, "auth_ref": [] }, "san_OtherFinancialLiabilitiesAtFairValueThroughProfitOrLossMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFinancialLiabilitiesAtFairValueThroughProfitOrLossMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other financial liabilities at FVTPL", "label": "Other Financial Liabilities At Fair Value Through Profit Or Loss [Member]", "documentation": "Other financial liabilities at fair value through profit or loss [member]" } } }, "auth_ref": [] }, "san_OtherFraudAndOperationalLossesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherFraudAndOperationalLossesMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other - fraud and operational losses", "label": "Other, Fraud And Operational Losses [Member]", "documentation": "Other, Fraud And Operational Losses" } } }, "auth_ref": [] }, "ifrs-full_OtherLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 6.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other liabilities", "label": "Other liabilities" } }, "en": { "role": { "documentation": "The amount of liabilities that the entity does not separately disclose in the same statement or note." } } }, "auth_ref": [ "r364" ] }, "san_OtherLiabilitiesRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherLiabilitiesRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 6.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other liabilities", "label": "Other Liabilities Recognised As Of Acquisition Date", "documentation": "Other Liabilities Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_OtherMortgageBackedSecuritisationStructuresMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherMortgageBackedSecuritisationStructuresMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other mortgage-backed securitisation structures:", "label": "Other Mortgage-Backed Securitisation Structures [Member]", "documentation": "Other Mortgage-Backed Securitisation Structures" } } }, "auth_ref": [] }, "ifrs-full_OtherOperatingIncomeExpense": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherOperatingIncomeExpense", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "san_NetOperatingIncome", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other operating income", "label": "Other operating income (expense)" } } }, "auth_ref": [ "r367" ] }, "ifrs-full_OtherReserves": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherReserves", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Equity", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Other reserves", "label": "Other reserves" } }, "en": { "role": { "documentation": "A component of equity representing reserves within equity, not including retained earnings. [Refer: Retained earnings]" } } }, "auth_ref": [ "r328", "r333" ] }, "san_OtherRestructuringAndSpecificProvisionsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherRestructuringAndSpecificProvisionsMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other - restructuring and specific provisions", "label": "Other, Restructuring And Specific Provisions [Member]", "documentation": "Other, Restructuring And Specific Provisions" } } }, "auth_ref": [] }, "san_OtherSecuritisationStructuresMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "OtherSecuritisationStructuresMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other asset-backed securitisation structures:", "label": "Other Securitisation Structures [member]", "documentation": "Other securitisation structures." } } }, "auth_ref": [] }, "ifrs-full_OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome", "crdr": "debit", "calculation": { "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Other non-deductible costs and non-taxable income", "label": "Other tax effects for reconciliation between accounting profit and tax expense (income)" } }, "en": { "role": { "documentation": "The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that the entity does not separately disclose in the same statement or note. [Refer: Accounting profit; Applicable tax rate]" } } }, "auth_ref": [ "r4", "r183" ] }, "san_POCIExpectedCreditLossNettingMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "POCIExpectedCreditLossNettingMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "POCI", "label": "POCI Expected Credit Loss, Netting [Member]", "documentation": "POCI Expected Credit Loss" } } }, "auth_ref": [] }, "san_POCIMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "POCIMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "POCI", "label": "POCI [Member]", "documentation": "POCI" } } }, "auth_ref": [] }, "ifrs-full_PaymentsForDebtIssueCosts": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PaymentsForDebtIssueCosts", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": -1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Issuance costs of debt securities and subordinated notes", "label": "Payments for debt issue costs" } }, "en": { "role": { "documentation": "The cash outflow for debt issue costs." } } }, "auth_ref": [ "r352" ] }, "ifrs-full_PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": -1.0, "order": 8.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Principal elements of lease payments", "label": "Payments of lease liabilities, classified as financing activities" } }, "en": { "role": { "documentation": "The cash outflow for payment of lease liabilities, classified as financing activities. [Refer: Lease liabilities]" } } }, "auth_ref": [ "r292" ] }, "ifrs-full_PaymentsOfOtherEquityInstruments": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PaymentsOfOtherEquityInstruments", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": -1.0, "order": 6.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Repurchase of other equity instruments", "label": "Payments of other equity instruments" } }, "en": { "role": { "documentation": "The cash outflow for payments for equity instruments that the entity does not separately disclose in the same statement or note." } } }, "auth_ref": [ "r352" ] }, "san_PensionRemeasurementAbstract": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PensionRemeasurementAbstract", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Pension remeasurement:", "label": "Pension Remeasurement [Abstract]", "documentation": "Pension remeasurement [abstract]" } } }, "auth_ref": [] }, "san_PercentageOfDefinedBenefitObligationInsured": { "xbrltype": "percentItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PercentageOfDefinedBenefitObligationInsured", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Percentage of defined benefit obligation insured", "label": "Percentage Of Defined Benefit Obligation Insured", "documentation": "Percentage Of Defined Benefit Obligation Insured" } } }, "auth_ref": [] }, "ifrs-full_PercentageOfReasonablyPossibleIncreaseInActuarialAssumption": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PercentageOfReasonablyPossibleIncreaseInActuarialAssumption", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofActuarialAssumptionSensitivitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Percentage of reasonably possible increase in actuarial assumption", "label": "Percentage of reasonably possible increase in actuarial assumption" } }, "en": { "role": { "documentation": "The reasonably possible percentage of the increase in the actuarial assumption used to determine the present value of defined benefit obligation. [Refer: Actuarial assumptions [domain]]" } } }, "auth_ref": [ "r19" ] }, "ifrs-full_PercentageOfVotingEquityInterestsAcquired": { "xbrltype": "percentItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PercentageOfVotingEquityInterestsAcquired", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Percentage of voting equity interests acquired", "label": "Percentage of voting equity interests acquired" } }, "en": { "role": { "documentation": "The percentage of voting equity interests acquired in a business combination. [Refer: Total for all business combinations [member]]" } } }, "auth_ref": [ "r106", "r218" ] }, "san_PercentageOnOtherEquityInterest": { "xbrltype": "pureItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PercentageOnOtherEquityInterest", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Interest rate", "label": "Percentage On Other Equity Interest", "documentation": "Percentage on other equity interest." } } }, "auth_ref": [] }, "ifrs-full_PlanAssetsAtFairValue": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PlanAssetsAtFairValue", "crdr": "debit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofNetAssetsRecognisedDetails": { "parentTag": "ifrs-full_LiabilityAssetOfDefinedBenefitPlans", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofNetAssetsRecognisedDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Fair value of scheme assets", "label": "Plan assets, at fair value" } }, "en": { "role": { "documentation": "The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]" } } }, "auth_ref": [ "r345" ] }, "san_PortfolioHedgesOfInterestRateRiskAdjustmentToHedgedAssetsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PortfolioHedgesOfInterestRateRiskAdjustmentToHedgedAssetsRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 6.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Macro hedge of interest rate risk", "label": "Portfolio Hedges Of Interest Rate Risk Adjustment To Hedged Assets, Recognised As Of Acquisition Date", "documentation": "Portfolio Hedges Of Interest Rate Risk Adjustment To Hedged Assets, Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_PortfolioHedgesOfInterestRateRiskAdjustmentToHedgedLiabilitiesRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PortfolioHedgesOfInterestRateRiskAdjustmentToHedgedLiabilitiesRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Macro hedge of interest rate risk", "label": "Portfolio Hedges Of Interest Rate Risk Adjustment To Hedged Liabilities, Recognised As Of Acquisition Date", "documentation": "Portfolio Hedges Of Interest Rate Risk Adjustment To Hedged Liabilities, Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_PostAcquisitionIntegrationCostsRecognisedInOperatingExpenses": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PostAcquisitionIntegrationCostsRecognisedInOperatingExpenses", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Post acquisition integration costs recognised in operating expenses", "label": "Post Acquisition Integration Costs Recognised In Operating Expenses", "documentation": "Post Acquisition Integration Costs Recognised In Operating Expenses" } } }, "auth_ref": [] }, "ifrs-full_PostemploymentBenefitExpenseDefinedBenefitPlans": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PostemploymentBenefitExpenseDefinedBenefitPlans", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Defined benefit expense", "label": "Post-employment benefit expense in profit or loss, defined benefit plans" } } }, "auth_ref": [ "r340", "r344" ] }, "ifrs-full_PostemploymentBenefitExpenseDefinedContributionPlans": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PostemploymentBenefitExpenseDefinedContributionPlans", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Defined contribution expense", "label": "Post-employment benefit expense, defined contribution plans" } } }, "auth_ref": [ "r22", "r188" ] }, "san_PoundsSterlingTenBillionGlobalCoveredBondProgrammeMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PoundsSterlingTenBillionGlobalCoveredBondProgrammeMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "\u00a310bn Global Covered Bond Programme", "label": "Pounds Sterling Ten Billion Global Covered Bond Programme [Member]", "documentation": "Pounds Sterling Ten Billion Global Covered Bond Programme" } } }, "auth_ref": [] }, "san_PreAcquisitionIntegrationCostsRecognisedInOperatingExpenses": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PreAcquisitionIntegrationCostsRecognisedInOperatingExpenses", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Pre acquisition costs recognised as expense", "label": "Pre Acquisition Integration Costs Recognised In Operating Expenses", "documentation": "Pre Acquisition Integration Costs Recognised In Operating Expenses" } } }, "auth_ref": [] }, "san_PreferredStockIssuedThreshold": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PreferredStockIssuedThreshold", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Preferred stock issued, threshold value", "label": "Preferred Stock Issued, Threshold", "documentation": "Preferred Stock Issued, Threshold" } } }, "auth_ref": [] }, "ifrs-full_PreviouslyStatedMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PreviouslyStatedMember", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "As originally published", "label": "Previously stated [member]" } }, "en": { "role": { "documentation": "This member stands for the information previously stated in the financial statements (ie before retrospective application or retrospective restatement)." } } }, "auth_ref": [ "r65", "r66", "r70", "r175", "r176", "r180", "r257" ] }, "ifrs-full_ProceedsFromDisposalsOfPropertyPlantAndEquipmentIntangibleAssetsOtherThanGoodwillInvestmentPropertyAndOtherNoncurrentAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProceedsFromDisposalsOfPropertyPlantAndEquipmentIntangibleAssetsOtherThanGoodwillInvestmentPropertyAndOtherNoncurrentAssets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Proceeds from sale of property, plant and equipment and intangible assets", "label": "Proceeds from disposals of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets" } }, "en": { "role": { "documentation": "The cash inflow from the disposal of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets. [Refer: Intangible assets other than goodwill; Investment property; Other non-current assets; Property, plant and equipment]" } } }, "auth_ref": [ "r351" ] }, "ifrs-full_ProceedsFromIssueOfBondsNotesAndDebentures": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProceedsFromIssueOfBondsNotesAndDebentures", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Issue of debt securities and subordinated notes", "label": "Proceeds from issue of bonds, notes and debentures" } }, "en": { "role": { "documentation": "The cash inflow from the issuing of bonds, notes and debentures." } } }, "auth_ref": [ "r352" ] }, "ifrs-full_ProceedsFromIssueOfOrdinaryShares": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProceedsFromIssueOfOrdinaryShares", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Issue of ordinary share capital", "label": "Proceeds from issue of ordinary shares" } }, "en": { "role": { "documentation": "The cash inflow from the issuing of ordinary shares. [Refer: Ordinary shares [member]]" } } }, "auth_ref": [ "r352" ] }, "ifrs-full_ProceedsFromIssuingOtherEquityInstruments": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProceedsFromIssuingOtherEquityInstruments", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "verboseLabel": "Issue of other equity instruments", "label": "Proceeds from issuing other equity instruments" } }, "en": { "role": { "documentation": "The cash inflow from issuing equity instruments that the entity does not separately disclose in the same statement or note." } } }, "auth_ref": [ "r291" ] }, "ifrs-full_ProceedsFromSalesOrMaturityOfFinancialInstrumentsClassifiedAsInvestingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProceedsFromSalesOrMaturityOfFinancialInstrumentsClassifiedAsInvestingActivities", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Proceeds from sale and redemption of financial assets at amortised cost and financial assets at FVOCI", "label": "Proceeds from sales or maturity of financial instruments, classified as investing activities" } }, "en": { "role": { "documentation": "The cash inflow from sales or maturity of financial instruments, classified as investing activities. [Refer: Classes of financial instruments [domain]]" } } }, "auth_ref": [ "r351" ] }, "ifrs-full_ProfitLoss": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProfitLoss", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_ComprehensiveIncome", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited", "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "totalLabel": "Profit after tax", "verboseLabel": "Profit after tax", "terseLabel": "Profit after tax", "label": "Profit (loss)" } }, "en": { "role": { "documentation": "The total of income less expenses from continuing and discontinued operations, excluding the components of other comprehensive income. [Refer: Other comprehensive income]" } } }, "auth_ref": [ "r72", "r74", "r154", "r155", "r195", "r217", "r258", "r272", "r294", "r299" ] }, "ifrs-full_ProfitLossAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProfitLossAbstract", "lang": { "en-us": { "role": { "terseLabel": "Profit (loss) [abstract]", "label": "Profit (loss) [abstract]" } } }, "auth_ref": [] }, "ifrs-full_ProfitLossBeforeTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProfitLossBeforeTax", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_ProfitLoss", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails", "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Profit before tax", "verboseLabel": "Profit before tax", "terseLabel": "Profit before tax", "label": "Profit (loss) before tax" } } }, "auth_ref": [ "r120", "r316", "r317", "r329", "r330" ] }, "san_ProfitLossBeforeTaxOfAcquireeSinceAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ProfitLossBeforeTaxOfAcquireeSinceAcquisitionDate", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Profit before tax of acquiree since acquisition date", "label": "Profit (Loss) Before Tax Of Acquiree Since Acquisition Date", "documentation": "Profit (Loss) Before Tax Of Acquiree Since Acquisition Date" } } }, "auth_ref": [] }, "ifrs-full_ProfitLossOfAcquiree": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProfitLossOfAcquiree", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Profit (loss) of acquiree since acquisition date", "label": "Profit (loss) of acquiree since acquisition date" } }, "en": { "role": { "documentation": "The profit (loss) of the acquiree, since the acquisition date, included in the consolidated statement of comprehensive income. [Refer: Profit (loss)]" } } }, "auth_ref": [ "r112" ] }, "ifrs-full_ProfitLossOfCombinedEntity": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProfitLossOfCombinedEntity", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Profit (loss) of combined entity as if combination occurred at beginning of period", "label": "Profit (loss) of combined entity as if combination occurred at beginning of period" } }, "en": { "role": { "documentation": "The profit (loss) of the combined entity as though the acquisition date for all business combinations that occurred during the year had been as of the beginning of the annual reporting period. [Refer: Total for all business combinations [member]; Profit (loss)]" } } }, "auth_ref": [ "r113" ] }, "san_ProjectByScenarioAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ProjectByScenarioAxis", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Project By Scenario [Axis]", "label": "Project By Scenario [Axis]", "documentation": "Project by scenario." } } }, "auth_ref": [] }, "san_ProjectByScenarioDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ProjectByScenarioDomain", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Project By Scenario [Domain]", "label": "Project By Scenario [Domain]", "documentation": "Project By Scenario [Domain]" } } }, "auth_ref": [] }, "san_PropertyMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PropertyMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Property", "label": "Property [Member]", "documentation": "a1e08f72-80dc-2908-a9a0-bbaef1f52a31" } } }, "auth_ref": [] }, "ifrs-full_PropertyPlantAndEquipmentIncludingRightofuseAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PropertyPlantAndEquipmentIncludingRightofuseAssets", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 12.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Property, plant and equipment", "periodStartLabel": "Property, plant and equipment including right-of-use assets at beginning of period", "periodEndLabel": "Property, plant and equipment including right-of-use assets at end of period", "label": "Property, plant and equipment including right-of-use assets" } }, "en": { "role": { "documentation": "The amount of property, plant and equipment including right-of-use assets whose underlying assets would be presented as property, plant and equipment if they were owned. [Refer: Property, plant and equipment; Right-of-use assets]" } } }, "auth_ref": [ "r99", "r339", "r363" ] }, "ifrs-full_PropertyPlantAndEquipmentIncludingRightofuseAssetsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PropertyPlantAndEquipmentIncludingRightofuseAssetsAxis", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Property, plant and equipment including right-of-use assets [axis]", "label": "Property, plant and equipment including right-of-use assets [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r339" ] }, "ifrs-full_PropertyPlantAndEquipmentIncludingRightofuseAssetsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PropertyPlantAndEquipmentIncludingRightofuseAssetsDomain", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Property, plant and equipment including right-of-use assets [domain]", "label": "Property, plant and equipment including right-of-use assets [domain]" } }, "en": { "role": { "documentation": "This member stands for a class of asset representing property, plant and equipment including right-of-use assets whose underlying assets would be presented as property, plant and equipment if they were owned. [Refer: Property, plant and equipment including right-of-use assets]" } } }, "auth_ref": [ "r339" ] }, "ifrs-full_PropertyPlantAndEquipmentRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PropertyPlantAndEquipmentRecognisedAsOfAcquisitionDate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableAssetsAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 9.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Property, plant and equipment", "label": "Property, plant and equipment recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for plant, property and equipment acquired in a business combination. [Refer: Property, plant and equipment; Total for all business combinations [member]]" } } }, "auth_ref": [ "r301", "r303", "r320" ] }, "ifrs-full_PropertyPlantAndEquipmentSubjectToOperatingLeasesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PropertyPlantAndEquipmentSubjectToOperatingLeasesMember", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Operating lease assets", "label": "Property, plant and equipment subject to operating leases [member]" } }, "en": { "role": { "documentation": "This member stands for property, plant and equipment that is subject to operating leases. Operating lease is a lease that does not transfer substantially all the risks and rewards incidental to ownership of an underlying asset. [Refer: Property, plant and equipment]" } } }, "auth_ref": [ "r101" ] }, "san_PropertyProvisionsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PropertyProvisionsMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Property provisions", "label": "Property Provisions [Member]", "documentation": "Property Provisions" } } }, "auth_ref": [] }, "san_ProvisionSubCategoryAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ProvisionSubCategoryAxis", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Provision Sub-Category [Axis]", "label": "Provision Sub-Category [Axis]", "documentation": "Provision Sub-Category" } } }, "auth_ref": [] }, "san_ProvisionSubCategoryDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ProvisionSubCategoryDomain", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Provision Sub-Category [Domain]", "label": "Provision Sub-Category [Domain]", "documentation": "Provision Sub-Category [Domain]" } } }, "auth_ref": [] }, "ifrs-full_ProvisionUsedOtherProvisions": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ProvisionUsedOtherProvisions", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Utilisation and other", "label": "Provision used, other provisions" } }, "en": { "role": { "documentation": "The amount used (ie incurred and charged against the provision) for other provisions. [Refer: Other provisions]" } } }, "auth_ref": [ "r38", "r202" ] }, "ifrs-full_Provisions": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "Provisions", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Provisions", "periodStartLabel": "Beginning balance", "periodEndLabel": "Ending balance", "label": "Provisions" } }, "en": { "role": { "documentation": "The amount of liabilities of uncertain timing or amount, including provisions for employee benefits." } } }, "auth_ref": [ "r267" ] }, "san_ProvisionsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ProvisionsRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 7.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Provisions", "label": "Provisions Recognised As Of Acquisition Date", "documentation": "Provisions Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "ifrs-full_PurchaseOfFinancialInstrumentsClassifiedAsInvestingActivities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PurchaseOfFinancialInstrumentsClassifiedAsInvestingActivities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities", "weight": -1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Purchase of financial assets at amortised cost and financial assets at FVOCI", "label": "Purchase of financial instruments, classified as investing activities" } }, "en": { "role": { "documentation": "The cash outflow for the purchase of financial instruments. [Refer: Classes of financial instruments [domain]]" } } }, "auth_ref": [ "r351" ] }, "ifrs-full_PurchaseOfPropertyPlantAndEquipmentIntangibleAssetsOtherThanGoodwillInvestmentPropertyAndOtherNoncurrentAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "PurchaseOfPropertyPlantAndEquipmentIntangibleAssetsOtherThanGoodwillInvestmentPropertyAndOtherNoncurrentAssets", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities", "weight": -1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Purchase of property, plant and equipment and intangible assets", "label": "Purchase of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets" } }, "en": { "role": { "documentation": "The cash outflow for the purchase of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets. [Refer: Intangible assets other than goodwill; Investment property; Other non-current assets; Property, plant and equipment]" } } }, "auth_ref": [ "r351" ] }, "san_PurchasePriceAllocationImpactMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PurchasePriceAllocationImpactMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Net impact on purchase price allocation", "label": "Purchase Price Allocation, Impact [Member]", "documentation": "Purchase Price Allocation, Impact" } } }, "auth_ref": [] }, "san_PurchasedCreditCardReceivablesPCCRMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "PurchasedCreditCardReceivablesPCCRMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/INTANGIBLEASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Purchased credit card receivables (PCCR)", "label": "Purchased Credit Card Receivables (PCCR) [Member]", "documentation": "Purchased Credit Card Receivables (PCCR)" } } }, "auth_ref": [] }, "ifrs-full_RangeAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RangeAxis", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Range [axis]", "label": "Range [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r62", "r94", "r103", "r105", "r172", "r296", "r298", "r358" ] }, "ifrs-full_RangeDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RangeDomain", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Range [domain]", "label": "Range [domain]" } }, "en": { "role": { "documentation": "This member stands for aggregate ranges. It also represents the standard value for the 'Range' axis if no other member is used." } } }, "auth_ref": [ "r62", "r94", "r103", "r105", "r172", "r296", "r298", "r358" ] }, "ifrs-full_ReclassificationAdjustmentsOnCashFlowHedgesBeforeTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReclassificationAdjustmentsOnCashFlowHedgesBeforeTax", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxCashFlowHedges", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "- Income statement transfers", "label": "Reclassification adjustments on cash flow hedges, before tax" } }, "en": { "role": { "documentation": "The amount of reclassification adjustments related to cash flow hedges, before tax. Reclassification adjustments are amounts reclassified to profit (loss) in the current period that were recognised in other comprehensive income in the current or previous periods. [Refer: Cash flow hedges [member]; Other comprehensive income]" } } }, "auth_ref": [ "r279" ] }, "ifrs-full_ReclassificationAdjustmentsOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReclassificationAdjustmentsOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited": { "parentTag": "ifrs-full_GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeNetOfTax", "weight": -1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofComprehensiveIncomeUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "- Income statement transfers", "label": "Reclassification adjustments on financial assets measured at fair value through other comprehensive income, before tax" } }, "en": { "role": { "documentation": "The amount of reclassification adjustments related to financial assets measured at fair value through other comprehensive income, before tax. Reclassification adjustments are amounts reclassified to profit (loss) in the current period that were recognised in other comprehensive income in the current or previous periods. [Refer: Financial assets measured at fair value through other comprehensive income; Other comprehensive income]" } } }, "auth_ref": [ "r123", "r229", "r279" ] }, "ifrs-full_RecognisedAssetsDefinedBenefitPlan": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RecognisedAssetsDefinedBenefitPlan", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "verboseLabel": "Retirement benefit assets", "label": "Net defined benefit asset" } }, "en": { "role": { "documentation": "The amount of surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]]" } } }, "auth_ref": [ "r364" ] }, "ifrs-full_RecognisedLiabilitiesDefinedBenefitPlan": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RecognisedLiabilitiesDefinedBenefitPlan", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 10.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "verboseLabel": "Retirement benefit obligations", "label": "Net defined benefit liability" } }, "en": { "role": { "documentation": "The amount of deficit in a defined benefit plan. [Refer: Defined benefit plans [domain]]" } } }, "auth_ref": [ "r364" ] }, "san_ReconciliationOfFairValueMeasurementsInLevelThreeOfTheFairValueHierarchyTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ReconciliationOfFairValueMeasurementsInLevelThreeOfTheFairValueHierarchyTableTextBlock", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Reconciliation of Fair Value Measurement in Level 3 of the Fair Value Hierarchy", "label": "Reconciliation Of Fair Value Measurements In Level Three Of The Fair Value Hierarchy [Table Text Block]", "documentation": "Reconciliation of fair value measurements in level 3 of the fair value hierarchy." } } }, "auth_ref": [] }, "san_ReducedHoursBranchesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ReducedHoursBranchesMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Reduced hours branches", "label": "Reduced Hours Branches [Member]", "documentation": "Reduced Hours Branches" } } }, "auth_ref": [] }, "san_RedundancyProvisionMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RedundancyProvisionMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Redundancy provision", "label": "Redundancy Provision [Member]", "documentation": "Redundancy Provision" } } }, "auth_ref": [] }, "san_RegulatoryCapital": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RegulatoryCapital", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Total capital", "label": "Regulatory Capital", "documentation": "Regulatory capital." } } }, "auth_ref": [] }, "san_RegulatoryFeesAndLevies": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RegulatoryFeesAndLevies", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "san_NetOperatingIncome", "weight": -1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Regulatory fees and levies", "label": "Regulatory Fees And Levies", "documentation": "Regulatory Fees And Levies" } } }, "auth_ref": [] }, "san_RegulatoryLeviesAndFeesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RegulatoryLeviesAndFeesMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Regulatory levies and fees", "label": "Regulatory Levies And Fees [Member]", "documentation": "Regulatory Levies And Fees" } } }, "auth_ref": [] }, "ifrs-full_RepaymentsOfBondsNotesAndDebentures": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RepaymentsOfBondsNotesAndDebentures", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited": { "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities", "weight": -1.0, "order": 5.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedCashFlowStatementUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Repayment of debt securities and subordinated notes", "label": "Repayments of bonds, notes and debentures" } }, "en": { "role": { "documentation": "The cash outflow for repayments of bonds, notes and debentures." } } }, "auth_ref": [ "r352" ] }, "san_ReptonMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ReptonMember", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Repton", "label": "Repton [Member]", "documentation": "Repton" } } }, "auth_ref": [] }, "srt_RepurchaseAgreementCounterpartyNameDomain": { "xbrltype": "domainItemType", "nsuri": "http://fasb.org/srt/2025", "localname": "RepurchaseAgreementCounterpartyNameDomain", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Counterparty Name [Domain]", "label": "Counterparty Name [Domain]" } } }, "auth_ref": [] }, "ifrs-full_RepurchaseAgreementsAndCashCollateralOnSecuritiesLent": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RepurchaseAgreementsAndCashCollateralOnSecuritiesLent", "crdr": "credit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialLiabilities", "weight": 1.0, "order": 2.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 8.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Repurchase agreements - non-trading", "label": "Repurchase agreements and cash collateral on securities lent" } }, "en": { "role": { "documentation": "The amount of instruments sold with the intent to reacquire in repurchase agreements and cash collateral on securities lent." } } }, "auth_ref": [ "r364" ] }, "san_RepurchaseAgreementsNonTradingMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RepurchaseAgreementsNonTradingMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Repurchase agreements - non-trading", "label": "Repurchase Agreements - Non-Trading [Member]", "documentation": "Repurchase agreements - non-trading." } } }, "auth_ref": [] }, "san_RepurchaseOfOtherEquityInstruments": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RepurchaseOfOtherEquityInstruments", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "negatedLabel": "Repurchase of other equity instruments", "label": "Repurchase Of Other Equity Instruments", "documentation": "Repurchase of other equity instruments." } } }, "auth_ref": [] }, "ifrs-full_ReserveOfCashFlowHedgesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReserveOfCashFlowHedgesMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cash flow hedging", "label": "Reserve of cash flow hedges [member]" } }, "en": { "role": { "documentation": "This member stands for a component of equity representing the accumulated portion of gain (loss) on a hedging instrument that is determined to be an effective hedge for cash flow hedges. [Refer: Cash flow hedges [member]]" } } }, "auth_ref": [ "r161", "r331" ] }, "ifrs-full_ReserveOfChangeInValueOfTimeValueOfOptionsMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReserveOfChangeInValueOfTimeValueOfOptionsMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Cost of hedging", "label": "Reserve of change in value of time value of options [member]" } }, "en": { "role": { "documentation": "This member stands for a component of equity representing the accumulated change in the value of the time value of options when separating the intrinsic value and time value of an option contract and designating as the hedging instrument only the changes in the intrinsic value." } } }, "auth_ref": [ "r162", "r331" ] }, "ifrs-full_ReserveOfExchangeDifferencesOnTranslationMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReserveOfExchangeDifferencesOnTranslationMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Currency translation", "label": "Reserve of exchange differences on translation [member]" } }, "en": { "role": { "documentation": "This member stands for a component of equity representing accumulated exchange differences on the translation of financial statements recognised in other comprehensive income. [Refer: Other comprehensive income]" } } }, "auth_ref": [ "r24", "r192", "r331" ] }, "ifrs-full_ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Fair value", "label": "Reserve of gains and losses on financial assets measured at fair value through other comprehensive income [member]" } }, "en": { "role": { "documentation": "This member stands for a component of equity representing the accumulated gains and losses on financial assets measured at fair value through other comprehensive income. [Refer: Financial assets measured at fair value through other comprehensive income; Other comprehensive income]" } } }, "auth_ref": [ "r331" ] }, "san_ResidualValueAndVoluntaryTerminationProvisions": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ResidualValueAndVoluntaryTerminationProvisions", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/LOANSANDADVANCESTOCUSTOMERSDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Residual value and voluntary termination provisions on finance leases", "label": "Residual Value And Voluntary Termination Provisions", "documentation": "Residual value and voluntary termination provisions." } } }, "auth_ref": [] }, "ifrs-full_RestatedMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RestatedMember", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Currently stated", "label": "Currently stated [member]" } }, "en": { "role": { "documentation": "This member stands for the information currently stated in the financial statements. It also represents the standard value for the 'Retrospective application and retrospective restatement' and 'Departure from requirement of IFRS' axes if no other member is used." } } }, "auth_ref": [ "r65", "r66", "r70", "r102", "r175", "r176", "r180", "r257", "r362" ] }, "san_RestructuringAndSpecificProvisions": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RestructuringAndSpecificProvisions", "crdr": "debit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "san_AggregateOperatingCreditImpairmentChargesWriteBacksRestructuringAndSpecificProvisions", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Restructuring and specific provisions", "label": "Restructuring And Specific Provisions", "documentation": "Restructuring And Specific Provisions" } } }, "auth_ref": [] }, "san_RestructuringProjectAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RestructuringProjectAxis", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Restructuring Project [Axis]", "label": "Restructuring Project [Axis]", "documentation": "Restructuring Project" } } }, "auth_ref": [] }, "san_RestructuringProjectDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RestructuringProjectDomain", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Restructuring Project [Domain]", "label": "Restructuring Project [Domain]", "documentation": "Restructuring Project [Domain]" } } }, "auth_ref": [] }, "ifrs-full_RestructuringProvisionMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RestructuringProvisionMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails", "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Restructuring", "label": "Restructuring provision [member]" } }, "en": { "role": { "documentation": "This member stands for a provision for restructuring, such as the sale or termination of a line of business; closure of business locations in a country or region or relocation of activities from one country or region to another; changes in management structure; and fundamental reorganisations that have a material effect on the nature and focus of the entity's operations. [Refer: Classes of other provisions [domain]]" } } }, "auth_ref": [ "r286" ] }, "san_RetailAndBusinessBankingMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RetailAndBusinessBankingMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Retail & Business Banking", "label": "Retail And Business Banking [Member]", "documentation": "Retail banking." } } }, "auth_ref": [] }, "san_RetailBusinessBankingMortgagesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RetailBusinessBankingMortgagesMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Mortgages", "label": "Retail & Business Banking, Mortgages [Member]", "documentation": "Retail banking." } } }, "auth_ref": [] }, "san_RetailDepositFundingPercentage": { "xbrltype": "percentItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RetailDepositFundingPercentage", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Retail deposit funding, percentage", "label": "Retail Deposit Funding, Percentage", "documentation": "Retail Deposit Funding, Percentage" } } }, "auth_ref": [] }, "ifrs-full_RetainedEarnings": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RetainedEarnings", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Equity", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Retained earnings", "label": "Retained earnings" } }, "en": { "role": { "documentation": "A component of equity representing the entity's cumulative undistributed earnings or deficit." } } }, "auth_ref": [ "r328", "r333", "r335" ] }, "ifrs-full_RetainedEarningsMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RetainedEarningsMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Retained earnings", "label": "Retained earnings [member]" } }, "en": { "role": { "documentation": "This member stands for a component of equity representing an entity's cumulative undistributed earnings or deficit." } } }, "auth_ref": [ "r261", "r331" ] }, "ifrs-full_RetrospectiveApplicationAndRetrospectiveRestatementAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RetrospectiveApplicationAndRetrospectiveRestatementAxis", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Retrospective application and retrospective restatement [axis]", "label": "Retrospective application and retrospective restatement [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r65", "r66", "r70", "r175", "r176", "r180", "r257" ] }, "ifrs-full_ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset", "crdr": "debit", "calculation": { "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails": { "parentTag": "ifrs-full_GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofAmountsRecognisedinOtherComprehensiveIncomeDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "(Loss) on plan assets (excluding amounts included in net interest expense)", "label": "Decrease (increase) in net defined benefit liability (asset) resulting from return on plan assets excluding interest income or expense" } }, "en": { "role": { "documentation": "The decrease (increase) in the net defined benefit liability (asset) resulting from the return on plan assets, excluding amounts included in interest income or expense. The return on plan assets is interest, dividends and other revenue derived from the plan assets, together with realised and unrealised gains or losses on the plan assets, less any costs of managing plan assets and less any tax payable by the plan itself, other than tax included in the actuarial assumptions used to measure the present value of the defined benefit obligation. [Refer: Plan assets [member]; Net defined benefit liability (asset); Actuarial assumptions [domain]; Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)]" } } }, "auth_ref": [ "r14", "r191" ] }, "ifrs-full_RevenueAndOperatingIncome": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RevenueAndOperatingIncome", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Inter-segment (expense)/revenue", "label": "Revenue and other operating income" } } }, "auth_ref": [ "r367" ] }, "ifrs-full_RevenueFromContractsWithCustomers": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RevenueFromContractsWithCustomers", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Revenue/(expense) from external customers", "label": "Revenue from contracts with customers" } } }, "auth_ref": [ "r95", "r96", "r166" ] }, "ifrs-full_RevenueFromInterest": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RevenueFromInterest", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited": { "parentTag": "ifrs-full_InterestRevenueExpense", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESChangeinaccountingpolicyDetails", "http://santander.co.uk/role/CondensedConsolidatedIncomeStatementUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Interest and similar income", "label": "Interest income" } }, "en": { "role": { "documentation": "The amount of income arising from interest." } } }, "auth_ref": [ "r81", "r151", "r158", "r361" ] }, "ifrs-full_RevenueOfAcquiree": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RevenueOfAcquiree", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Revenue of acquiree since acquisition date", "label": "Revenue of acquiree since acquisition date" } } }, "auth_ref": [ "r112" ] }, "ifrs-full_RevenueOfCombinedEntity": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RevenueOfCombinedEntity", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Revenue of combined entity as if combination occurred at beginning of period", "label": "Revenue of combined entity as if combination occurred at beginning of period" } } }, "auth_ref": [ "r113" ] }, "ifrs-full_ReverseRepurchaseAgreementsAndCashCollateralOnSecuritiesBorrowed": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "ReverseRepurchaseAgreementsAndCashCollateralOnSecuritiesBorrowed", "crdr": "debit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialAssets", "weight": 1.0, "order": 4.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Assets", "weight": 1.0, "order": 13.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Reverse repurchase agreements - non-trading", "verboseLabel": "Reverse repurchase agreements - non-trading", "label": "Reverse repurchase agreements and cash collateral on securities borrowed" } }, "en": { "role": { "documentation": "The amount of instruments purchased for resale in reverse repurchase agreements and cash collateral on securities borrowed. [Refer: Repurchase agreements and cash collateral on securities lent]" } } }, "auth_ref": [ "r364" ] }, "san_ReverseRepurchaseAgreementsNonTradingMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ReverseRepurchaseAgreementsNonTradingMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Reverse repurchase agreements - non-trading", "label": "Reverse Repurchase Agreements - Non-Trading [Member]", "documentation": "Reverse repurchase agreements - non-trading." } } }, "auth_ref": [] }, "ifrs-full_RightofuseAssetsMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "RightofuseAssetsMember", "presentation": [ "http://santander.co.uk/role/PROPERTYPLANTANDEQUIPMENTDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Right-of-use assets", "label": "Right-of-use assets [member]" } }, "en": { "role": { "documentation": "This member stands for right-of-use assets. [Refer: Right-of-use assets]" } } }, "auth_ref": [ "r98" ] }, "san_RiskRelatedAdjustmentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RiskRelatedAdjustmentsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Risk-related:", "label": "Risk Related Adjustments [Member]", "documentation": "Risk related adjustments." } } }, "auth_ref": [] }, "san_RiskRelatedFundingFairValueAdjustmentMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RiskRelatedFundingFairValueAdjustmentMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Funding fair value adjustment", "label": "Risk Related Funding Fair Value Adjustment [Member]", "documentation": "Funding fair value adjustment." } } }, "auth_ref": [] }, "san_RiskRelatedUncertaintyAdjustmentsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "RiskRelatedUncertaintyAdjustmentsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofFairValueAdjustmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- Uncertainty", "label": "Risk Related Uncertainty Adjustments [Member]", "documentation": "Uncertainty." } } }, "auth_ref": [] }, "san_SantanderUKLiabilityUnderIndemnityCap": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SantanderUKLiabilityUnderIndemnityCap", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Santander UK liability under indemnity cap", "label": "Santander UK Liability Under Indemnity Cap", "documentation": "Santander UK Liability Under Indemnity Cap" } } }, "auth_ref": [] }, "san_SantanderUkPlcMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SantanderUkPlcMember", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Santander UK Plc", "label": "Santander UK Plc [member]", "documentation": "Santander UK plc." } } }, "auth_ref": [] }, "srt_ScenarioForecastMember": { "xbrltype": "domainItemType", "nsuri": "http://fasb.org/srt/2025", "localname": "ScenarioForecastMember", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Forecast", "label": "Forecast [Member]" } } }, "auth_ref": [] }, "srt_ScenarioUnspecifiedDomain": { "xbrltype": "domainItemType", "nsuri": "http://fasb.org/srt/2025", "localname": "ScenarioUnspecifiedDomain", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Scenario [Domain]", "label": "Scenario [Domain]" } } }, "auth_ref": [] }, "san_ScheduleOfFairValueAdjustmentExplanatoryTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ScheduleOfFairValueAdjustmentExplanatoryTableTextBlock", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Fair Value Adjustment", "label": "Schedule Of Fair Value Adjustment Explanatory [Table Text Block]", "documentation": "Schedule of fair value adjustment explanatory." } } }, "auth_ref": [] }, "san_SecuritisationAndCoveredBondsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationAndCoveredBondsMember", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisations and covered bonds", "label": "Securitisation And Covered Bonds [Member]", "documentation": "Securitisations and covered bonds." } } }, "auth_ref": [] }, "san_SecuritisationByCompanyNameAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationByCompanyNameAxis", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisation By Company Name [Axis]", "label": "Securitisation By Company Name [axis]", "documentation": "Securitisation By Company Name [axis]" } } }, "auth_ref": [] }, "san_SecuritisationByCompanyNameDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationByCompanyNameDomain", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisation By Company Name [Domain]", "label": "Securitisation By Company Name [domain]", "documentation": "Securitisation By Company Name [domain]" } } }, "auth_ref": [] }, "san_SecuritisationByProgramNameAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationByProgramNameAxis", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisation By Program Name [Axis]", "label": "Securitisation By Program Name [Axis]", "documentation": "Securitisation By Program Name [Axis]" } } }, "auth_ref": [] }, "san_SecuritisationByProgramNameDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationByProgramNameDomain", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisation By Program Name [Domain]", "label": "Securitisation By Program Name [Domain]", "documentation": "Securitisation By Program Name [domain]" } } }, "auth_ref": [] }, "san_SecuritisationProgrammesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationProgrammesMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisation programmes", "label": "Securitisation Programmes [Member]", "documentation": "Securitisation programmes." } } }, "auth_ref": [] }, "san_SecuritisationsAndCoveredBondsIssued": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationsAndCoveredBondsIssued", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisations and covered bonds issued", "label": "Securitisations And Covered Bonds Issued", "documentation": "Securitisations And Covered Bonds Issued" } } }, "auth_ref": [] }, "san_SecuritisationsAndCoveredBondsRedeemed": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SecuritisationsAndCoveredBondsRedeemed", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Securitisations and covered bonds redeemed", "label": "Securitisations And Covered Bonds Redeemed", "documentation": "Securitisations And Covered Bonds Redeemed" } } }, "auth_ref": [] }, "ifrs-full_SegmentConsolidationItemsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SegmentConsolidationItemsAxis", "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Segment consolidation items [axis]", "label": "Segment consolidation items [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r154" ] }, "ifrs-full_SegmentConsolidationItemsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SegmentConsolidationItemsDomain", "presentation": [ "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Segment consolidation items [domain]", "label": "Segment consolidation items [domain]" } }, "en": { "role": { "documentation": "This member stands for the standard value for the 'Segment consolidation items' axis if no other member is used." } } }, "auth_ref": [ "r159" ] }, "ifrs-full_SegmentsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SegmentsAxis", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Segments [axis]", "label": "Segments [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r32", "r97", "r154", "r167", "r284", "r300" ] }, "ifrs-full_SegmentsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SegmentsDomain", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails", "http://santander.co.uk/role/SEGMENTSSummaryofResultsbySegmentDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Segments [domain]", "label": "Segments [domain]" } }, "en": { "role": { "documentation": "This member stands for all segments of an entity. It also represents the standard value for the 'Segments' axis if no other member is used." } } }, "auth_ref": [ "r32", "r97", "r159", "r167", "r284", "r300" ] }, "san_SeniorUnsecuredDebtSecuritiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SeniorUnsecuredDebtSecuritiesMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Senior unsecured debt securities", "label": "Senior Unsecured Debt Securities [Member]", "documentation": "Senior Unsecured Debt Securities" } } }, "auth_ref": [] }, "san_SensitivityAnalysisForFairValueMeasurementReasonablyPossibleChange": { "xbrltype": "percentItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SensitivityAnalysisForFairValueMeasurementReasonablyPossibleChange", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Sensitivity analysis for fair value measurement reasonably possible change", "label": "Sensitivity Analysis For Fair Value Measurement Reasonably Possible Change", "documentation": "Sensitivity Analysis For Fair Value Measurement Reasonably Possible Change" } } }, "auth_ref": [] }, "ifrs-full_SettlementsFairValueMeasurementAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SettlementsFairValueMeasurementAssets", "crdr": "credit", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "negatedLabel": "Settlements", "label": "Settlements, fair value measurement, assets" } }, "en": { "role": { "documentation": "The decrease in the fair value measurement of assets resulting from settlements. [Refer: At fair value [member]]" } } }, "auth_ref": [ "r90" ] }, "ifrs-full_SettlementsFairValueMeasurementLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SettlementsFairValueMeasurementLiabilities", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSSummaryofReconciliationofFairValueMeasurementinLevel3oftheFairValueHierarchyDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Settlements", "label": "Settlements, fair value measurement, liabilities" } }, "en": { "role": { "documentation": "The decrease in the fair value measurement of liabilities resulting from settlements. [Refer: At fair value [member]]" } } }, "auth_ref": [ "r90" ] }, "san_SevenHundredAndFiftyMillionFixedRateResetPerpetualATOneCapitalSecuritiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SevenHundredAndFiftyMillionFixedRateResetPerpetualATOneCapitalSecuritiesMember", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- \u00a3750m Perpetual Capital Securities", "label": "Seven Hundred And Fifty Million Fixed Rate Reset Perpetual AT One Capital Securities [Member]", "documentation": "Seven Hundred And Fifty Million Fixed Rate Reset Perpetual AT One Capital Securities" } } }, "auth_ref": [] }, "ifrs-full_SharePremium": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SharePremium", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Equity", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Share premium", "label": "Share premium" } }, "en": { "role": { "documentation": "The amount received or receivable from the issuance of the entity's shares in excess of nominal value." } } }, "auth_ref": [ "r328", "r333" ] }, "ifrs-full_SharePremiumMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SharePremiumMember", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Share premium", "label": "Share premium [member]" } }, "en": { "role": { "documentation": "This member stands for the amount received or receivable from issuance of the entity's shares in excess of nominal value." } } }, "auth_ref": [ "r261" ] }, "ifrs-full_SignificantInvestmentsInSubsidiariesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SignificantInvestmentsInSubsidiariesAxis", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Subsidiaries [axis]", "label": "Subsidiaries [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r28", "r29", "r84", "r244" ] }, "ifrs-full_SignificantInvestmentsInSubsidiariesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SignificantInvestmentsInSubsidiariesDomain", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Subsidiaries [domain]", "label": "Subsidiaries [domain]" } }, "en": { "role": { "documentation": "This member stands for the standard value for the 'Subsidiaries' axis if no other member is used." } } }, "auth_ref": [ "r28", "r29", "r84", "r244" ] }, "ifrs-full_SignificantUnobservableInputAssets": { "xbrltype": "decimalItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SignificantUnobservableInputAssets", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Significant unobservable input, assets", "label": "Significant unobservable input, assets" } }, "en": { "role": { "documentation": "The value of significant unobservable input used in the measurement of the fair value of assets." } } }, "auth_ref": [ "r88" ] }, "san_StageOneExpectedCreditLossMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StageOneExpectedCreditLossMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Stage 1", "label": "Stage One Expected Credit Loss [Member]", "documentation": "Stage one expected credit loss." } } }, "auth_ref": [] }, "san_StageOneMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StageOneMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "\u2013Stage 1", "label": "Stage One [Member]", "documentation": "e59bb779-20f2-d44e-7216-bbaef21969d2" } } }, "auth_ref": [] }, "san_StageThreeExpectedCreditLossMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StageThreeExpectedCreditLossMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Stage 3", "label": "Stage Three Expected Credit Loss [Member]", "documentation": "Stage three expected credit loss." } } }, "auth_ref": [] }, "san_StageThreeMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StageThreeMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "\u2013Stage 3", "label": "Stage Three [Member]", "documentation": "Stage 3." } } }, "auth_ref": [] }, "san_StageTwoExpectedCreditLossMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StageTwoExpectedCreditLossMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Stage 2", "label": "Stage Two Expected Credit Loss [Member]", "documentation": "Stage two expected credit loss." } } }, "auth_ref": [] }, "san_StageTwoMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StageTwoMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "\u2013Stage 2", "label": "Stage Two [member]", "documentation": "Stage 2." } } }, "auth_ref": [] }, "san_StandbyFacilitiesCreditLinesAndOtherCommitments": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StandbyFacilitiesCreditLinesAndOtherCommitments", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails": { "parentTag": "san_EstimatedFinancialEffectOfContingentLiabilitiesAndCommitments", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSSummaryofContingentLiabilitiesandCommitmentsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Formal standby facilities, credit lines and other commitments", "label": "Standby Facilities Credit Lines And Other Commitments", "documentation": "Standby facilities credit lines and other commitments." } } }, "auth_ref": [] }, "ifrs-full_StatementOfCashFlowsAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "StatementOfCashFlowsAbstract", "lang": { "en-us": { "role": { "terseLabel": "Statement of cash flows [abstract]", "label": "Statement of cash flows [abstract]" } } }, "auth_ref": [] }, "ifrs-full_StatementOfChangesInEquityAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "StatementOfChangesInEquityAbstract", "lang": { "en-us": { "role": { "terseLabel": "Statement of changes in equity [abstract]", "label": "Statement of changes in equity [abstract]" } } }, "auth_ref": [] }, "ifrs-full_StatementOfChangesInEquityLineItems": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "StatementOfChangesInEquityLineItems", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Statement of changes in equity [line items]", "label": "Statement of changes in equity [line items]" } }, "en": { "role": { "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table." } } }, "auth_ref": [] }, "ifrs-full_StatementOfChangesInEquityTable": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "StatementOfChangesInEquityTable", "presentation": [ "http://santander.co.uk/role/CondensedConsolidatedStatementofChangesinEquityUnaudited" ], "lang": { "en-us": { "role": { "terseLabel": "Statement of changes in equity [table]", "label": "Statement of changes in equity [table]" } }, "en": { "role": { "documentation": "Schedule disclosing information related to changes in equity." } } }, "auth_ref": [ "r261" ] }, "ifrs-full_StatementOfComprehensiveIncomeAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "StatementOfComprehensiveIncomeAbstract", "lang": { "en-us": { "role": { "terseLabel": "Statement of comprehensive income [abstract]", "label": "Statement of comprehensive income [abstract]" } } }, "auth_ref": [] }, "ifrs-full_StatementOfFinancialPositionAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "StatementOfFinancialPositionAbstract", "lang": { "en-us": { "role": { "terseLabel": "Statement of financial position [abstract]", "label": "Statement of financial position [abstract]" } } }, "auth_ref": [] }, "srt_StatementScenarioAxis": { "xbrltype": "stringItemType", "nsuri": "http://fasb.org/srt/2025", "localname": "StatementScenarioAxis", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Scenario [Axis]", "label": "Scenario [Axis]" } } }, "auth_ref": [] }, "san_SterlingPreferenceSharesNotionalAmount": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SterlingPreferenceSharesNotionalAmount", "presentation": [ "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "\u00a3325m Sterling preference shares, notional amount", "label": "Sterling Preference Shares Notional Amount", "documentation": "The nominal or face amount of an equity instrument, used to calculate payments made on that instrument." } } }, "auth_ref": [] }, "san_StructuredDepositsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StructuredDepositsMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsMeasuredatFairValueonaRecurringBasisDetails", "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Structured deposits", "label": "Structured Deposits [Member]", "documentation": "3c02f63d-79d8-f323-d771-bbaef2351358" } } }, "auth_ref": [] }, "san_StructuredNotesProgrammesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "StructuredNotesProgrammesMember", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Structured Notes Programmes", "label": "Structured Notes Programmes [Member]", "documentation": "Structured notes programmes [member]" } } }, "auth_ref": [] }, "ifrs-full_SubordinatedLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SubordinatedLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails": { "parentTag": "ifrs-full_FinancialLiabilities", "weight": 1.0, "order": 1.0 }, "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited": { "parentTag": "ifrs-full_Liabilities", "weight": 1.0, "order": 3.0 }, "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails": { "parentTag": null, "weight": null, "order": null, "root": true } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/CondensedConsolidatedBalanceSheetUnaudited", "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails", "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Subordinated liabilities", "totalLabel": "Subordinated liabilities", "verboseLabel": "Subordinated liabilities", "label": "Subordinated liabilities" } }, "en": { "role": { "documentation": "The amount of liabilities that are subordinate to other liabilities with respect to claims." } } }, "auth_ref": [ "r364" ] }, "ifrs-full_SubordinatedLiabilitiesAbstract": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SubordinatedLiabilitiesAbstract", "lang": { "en-us": { "role": { "label": "Subordinated liabilities [abstract]" } } }, "auth_ref": [] }, "san_SubordinatedLiabilitiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SubordinatedLiabilitiesMember", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSDisclosureofAnalysisofFairValueofFinancialInstrumentsCarriedatAmortisedCostDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Subordinated liabilities", "label": "Subordinated Liabilities [member]", "documentation": "Subordinated liabilities." } } }, "auth_ref": [] }, "san_SubordinatedLiabilitiesRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SubordinatedLiabilitiesRecognisedAsOfAcquisitionDate", "crdr": "credit", "calculation": { "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails": { "parentTag": "san_IdentifiableLiabilitiesAcquiredRecognisedAsOfAcquisitionDate", "weight": 1.0, "order": 9.0 } }, "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Subordinated liabilities", "label": "Subordinated Liabilities Recognised As Of Acquisition Date", "documentation": "Subordinated Liabilities Recognised As Of Acquisition Date" } } }, "auth_ref": [] }, "san_SummaryOfRelationshipBetweenCustomerLiabilitiesAndDepositsTableTextBlock": { "xbrltype": "textBlockItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SummaryOfRelationshipBetweenCustomerLiabilitiesAndDepositsTableTextBlock", "presentation": [ "http://santander.co.uk/role/SEGMENTSTables" ], "lang": { "en-us": { "role": { "terseLabel": "Summary of Relationship Between Customer Liabilities and Deposits", "label": "Summary Of Relationship Between Customer Liabilities And Deposits [Table Text Block]", "documentation": "Summary Of Relationship Between Customer Liabilities And Deposits" } } }, "auth_ref": [] }, "ifrs-full_SurplusDeficitInPlan": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "SurplusDeficitInPlan", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Surplus (deficit) in plan", "label": "Surplus (deficit) in plan" } }, "en": { "role": { "documentation": "The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]" } } }, "auth_ref": [ "r345" ] }, "san_SurplusMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "SurplusMember", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Surplus", "label": "Surplus [member]", "documentation": "Surplus." } } }, "auth_ref": [] }, "san_TSBCoveredBondsHoldingsLtdAndTSBBankingGroupPlcEmployeeShareTrustMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TSBCoveredBondsHoldingsLtdAndTSBBankingGroupPlcEmployeeShareTrustMember", "presentation": [ "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "TSB Covered Bonds (Holdings) Ltd and TSB Banking Group plc Employee Share Trust", "label": "TSB Covered Bonds (Holdings) Ltd and TSB Banking Group plc Employee Share Trust [Member]", "documentation": "TSB and TSB Covered Bonds" } } }, "auth_ref": [] }, "san_TSBCoveredBondsLMMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TSBCoveredBondsLMMember", "presentation": [ "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "TSB Covered Bonds (LM)", "label": "TSB Covered Bonds (LM) [Member]", "documentation": "TSB Covered Bonds (LM)" } } }, "auth_ref": [] }, "san_TSBMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TSBMember", "presentation": [ "http://santander.co.uk/role/ACCOUNTINGPOLICIESCriticaljudgementsandaccountingestimatesDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBNetcashflowfromacquisitionDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBSummaryofdetailedinformationaboutbusinesscombinationDetails", "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails", "http://santander.co.uk/role/CREDITIMPAIRMENTCHARGESAdditionalInformationDetails", "http://santander.co.uk/role/INTERESTSINOTHERENTITIESDetails" ], "lang": { "en-us": { "role": { "terseLabel": "TSB", "label": "TSB [Member]", "documentation": "TSB" } } }, "auth_ref": [] }, "san_TaxEffectOfBankCorporationTaxSurchargeOnProfits": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TaxEffectOfBankCorporationTaxSurchargeOnProfits", "crdr": "debit", "calculation": { "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Bank surcharge on profits", "label": "Tax Effect Of Bank Corporation Tax Surcharge On Profits", "documentation": "Tax effect of bank corporation tax surcharge on profits." } } }, "auth_ref": [] }, "san_TaxEffectOfNonDeductiblePreferenceDividendsPaid": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TaxEffectOfNonDeductiblePreferenceDividendsPaid", "crdr": "debit", "calculation": { "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations", "weight": 1.0, "order": 3.0 } }, "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Non-deductible preference dividends paid", "label": "Tax Effect Of Non Deductible Preference Dividends Paid", "documentation": "Tax effect of non-deductible preference dividends paid." } } }, "auth_ref": [] }, "san_TaxEffectOfNonDeductibleUKBankLevy": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TaxEffectOfNonDeductibleUKBankLevy", "crdr": "debit", "calculation": { "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations", "weight": 1.0, "order": 4.0 } }, "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Non-deductible UK Bank Levy", "label": "Tax Effect Of Non Deductible UK Bank Levy", "documentation": "Tax effect of non-deductible bank levy." } } }, "auth_ref": [] }, "san_TaxEffectOfPriorYearAdjustments": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TaxEffectOfPriorYearAdjustments", "crdr": "debit", "calculation": { "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations", "weight": 1.0, "order": 7.0 } }, "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Adjustment to prior year provisions", "label": "Tax Effect Of Prior Year Adjustments", "documentation": "Tax effect of prior year adjustments." } } }, "auth_ref": [] }, "ifrs-full_TaxExpenseIncomeAtApplicableTaxRate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TaxExpenseIncomeAtApplicableTaxRate", "crdr": "debit", "calculation": { "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Tax calculated at the statutory rate of 25% (H1-25: 25%)", "label": "Tax expense (income) at applicable tax rate" } }, "en": { "role": { "documentation": "The product of the accounting profit multiplied by the applicable tax rate(s). [Refer: Accounting profit; Applicable tax rate]" } } }, "auth_ref": [ "r4", "r183" ] }, "san_TaxReliefOnDividendsInRespectOfOtherEquityInstruments": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TaxReliefOnDividendsInRespectOfOtherEquityInstruments", "crdr": "debit", "calculation": { "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails": { "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations", "weight": 1.0, "order": 6.0 } }, "presentation": [ "http://santander.co.uk/role/TAXATIONScheduleofTaxonProfitBeforeTaxDiffersfromTheoreticalAmountthatAriseUsingBasicCorporationTaxRateDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Tax relief on dividends in respect of other equity instruments", "label": "Tax Relief On Dividends In Respect Of Other Equity Instruments", "documentation": "Tax relief on dividends in respect of other equity instruments." } } }, "auth_ref": [] }, "ifrs-full_TechnologybasedIntangibleAssetsRecognisedAsOfAcquisitionDate": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TechnologybasedIntangibleAssetsRecognisedAsOfAcquisitionDate", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Technology-based intangible assets recognised as of acquisition date", "label": "Technology-based intangible assets recognised as of acquisition date" } }, "en": { "role": { "documentation": "The amount recognised as of the acquisition date for technology-based intangible assets acquired in a business combination. [Refer: Technology-based intangible assets [member]; Total for all business combinations [member]]" } } }, "auth_ref": [ "r357" ] }, "san_ThirdPartyBilateralSecuredFundingTransactionsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ThirdPartyBilateralSecuredFundingTransactionsMember", "presentation": [ "http://santander.co.uk/role/ASSETSCHARGEDASSECURITYFORLIABILITIESANDCOLLATERALACCEPTEDASSECURITYFORASSETSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Third party bilateral secured funding transactions", "label": "Third Party Bilateral Secured Funding Transactions [member]", "documentation": "Third party bilateral secured funding transactions." } } }, "auth_ref": [] }, "san_TierOneCapitalAmount": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TierOneCapitalAmount", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails": { "parentTag": "san_RegulatoryCapital", "weight": 1.0, "order": 1.0 } }, "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "totalLabel": "Tier 1 capital", "label": "Tier One Capital Amount", "documentation": "Tier one capital amount." } } }, "auth_ref": [] }, "san_TierTwoCapitalAmount": { "xbrltype": "monetaryItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TierTwoCapitalAmount", "crdr": "credit", "calculation": { "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails": { "parentTag": "san_RegulatoryCapital", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Tier 2 capital", "label": "Tier Two Capital Amount", "documentation": "Tier Two Capital Amount" } } }, "auth_ref": [] }, "ifrs-full_TopOfRangeMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TopOfRangeMember", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Maximum", "label": "Top of range [member]" } }, "en": { "role": { "documentation": "This member stands for top of a range." } } }, "auth_ref": [ "r62", "r94", "r103", "r105", "r172", "r296", "r298", "r358" ] }, "san_TotalExposureMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TotalExposureMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Exposures", "label": "Total Exposure [Member]", "documentation": "Total exposure." } } }, "auth_ref": [] }, "ifrs-full_TradeAndOtherPayablesToRelatedParties": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TradeAndOtherPayablesToRelatedParties", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_DepositsFromCustomers", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Intercompany balances (including joint ventures)", "label": "Payables to related parties" } }, "en": { "role": { "documentation": "The amount of payables due to related parties. [Refer: Total for all related parties [member]]" } } }, "auth_ref": [ "r366" ] }, "ifrs-full_TradeAndOtherReceivablesDueFromRelatedParties": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TradeAndOtherReceivablesDueFromRelatedParties", "crdr": "debit", "calculation": { "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails": { "parentTag": "ifrs-full_LoansAndAdvancesToCustomers", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/SEGMENTSScheduleOfRelationshipbetweenCustomerAssetsandLoansandAdvancesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Intercompany balances (including joint ventures)", "label": "Receivables due from related parties" } }, "en": { "role": { "documentation": "The amount of receivables due from related parties. [Refer: Total for all related parties [member]]" } } }, "auth_ref": [ "r327", "r332" ] }, "ifrs-full_TransfersOutOfLevel1IntoLevel2OfFairValueHierarchyAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TransfersOutOfLevel1IntoLevel2OfFairValueHierarchyAssets", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers out of Level 1 into Level 2 of fair value hierarchy, assets", "label": "Transfers out of Level 1 into Level 2 of fair value hierarchy, assets held at end of reporting period" } }, "en": { "role": { "documentation": "The amount of transfers out of Level 1 and into Level 2 of the fair value hierarchy of assets held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]" } } }, "auth_ref": [ "r87" ] }, "ifrs-full_TransfersOutOfLevel1IntoLevel2OfFairValueHierarchyLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TransfersOutOfLevel1IntoLevel2OfFairValueHierarchyLiabilities", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers out of Level 1 into Level 2 of fair value hierarchy, liabilities", "label": "Transfers out of Level 1 into Level 2 of fair value hierarchy, liabilities held at end of reporting period" } }, "en": { "role": { "documentation": "The amount of transfers out of Level 1 and into Level 2 of the fair value hierarchy of liabilities held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]" } } }, "auth_ref": [ "r87" ] }, "ifrs-full_TransfersOutOfLevel2IntoLevel1OfFairValueHierarchyAssets": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TransfersOutOfLevel2IntoLevel1OfFairValueHierarchyAssets", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers out of Level 2 into Level 1 of fair value hierarchy, assets", "label": "Transfers out of Level 2 into Level 1 of fair value hierarchy, assets held at end of reporting period" } }, "en": { "role": { "documentation": "The amount of transfers out of Level 2 and into Level 1 of the fair value hierarchy of assets held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]" } } }, "auth_ref": [ "r87" ] }, "ifrs-full_TransfersOutOfLevel2IntoLevel1OfFairValueHierarchyLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TransfersOutOfLevel2IntoLevel1OfFairValueHierarchyLiabilities", "presentation": [ "http://santander.co.uk/role/FINANCIALINSTRUMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transfers out of Level 2 into Level 1 of fair value hierarchy, liabilities", "label": "Transfers out of Level 2 into Level 1 of fair value hierarchy, liabilities held at end of reporting period" } }, "en": { "role": { "documentation": "The amount of transfers out of Level 2 and into Level 1 of the fair value hierarchy of liabilities held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]" } } }, "auth_ref": [ "r87" ] }, "san_TransitionalIFRS9BenefitMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TransitionalIFRS9BenefitMember", "presentation": [ "http://santander.co.uk/role/CapitalRiskSummaryofRegulatoryCapitalResourcesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Transitional IFRS 9 Benefit", "label": "Transitional IFRS 9 Benefit [Member]", "documentation": "Transitional IFRS 9 Benefit" } } }, "auth_ref": [] }, "ifrs-full_TwelvemonthExpectedCreditLossesMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TwelvemonthExpectedCreditLossesMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Subject to 12-month ECL", "label": "12-month expected credit losses [member]" } }, "en": { "role": { "documentation": "This member stands for the portion of lifetime expected credit losses that represent the expected credit losses that result from default events on a financial instrument that are possible within the 12 months after the reporting date. [Refer: Type of measurement of expected credit losses [domain]; Lifetime expected credit losses [member]]" } } }, "auth_ref": [ "r128", "r134", "r234", "r240" ] }, "san_TwoHundredAndTenMillionFixedRateResetPerpetualATOneCapitalSecuritiesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TwoHundredAndTenMillionFixedRateResetPerpetualATOneCapitalSecuritiesMember", "presentation": [ "http://santander.co.uk/role/OTHEREQUITYINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "- \u00a3210m Perpetual Capital Securities", "label": "Two Hundred And Ten Million Fixed Rate Reset Perpetual AT One Capital Securities [Member]", "documentation": "Two Hundred And Ten Million Fixed Rate Reset Perpetual AT One Capital Securities" } } }, "auth_ref": [] }, "ifrs-full_TypeOfMeasurementOfExpectedCreditLossesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TypeOfMeasurementOfExpectedCreditLossesAxis", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Type of measurement of expected credit losses [axis]", "label": "Type of measurement of expected credit losses [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r131", "r137", "r237", "r243" ] }, "ifrs-full_TypeOfMeasurementOfExpectedCreditLossesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TypeOfMeasurementOfExpectedCreditLossesDomain", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofECLReconciliationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Type of measurement of expected credit losses [domain]", "label": "Type of measurement of expected credit losses [domain]" } }, "en": { "role": { "documentation": "This member stands for all types of measurement of expected credit losses. Expected credit losses are the weighted average of credit losses with the respective risks of a default occurring as the weights. This member also represents the standard value for the 'Type of measurement of expected credit losses' axis if no other member is used." } } }, "auth_ref": [ "r131", "r137", "r237", "r243" ] }, "san_TypeOfSecuritisationAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TypeOfSecuritisationAxis", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Type Of Securitisation [Axis]", "label": "Type Of Securitisation [Axis]", "documentation": "Type Of Securitisation." } } }, "auth_ref": [] }, "san_TypeOfSecuritisationDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TypeOfSecuritisationDomain", "presentation": [ "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSAdditionalInformationDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSDisclosureofAnalysisofSecuritisationsandCoveredBondsDetails", "http://santander.co.uk/role/SECURITISATIONSANDCOVEREDBONDSSummaryofIssuancesandRedemptionsofSecuritisationandCoveredBondProgrammeDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Type Of Securitisation [Domain]", "label": "Type Of Securitisation [Domain]", "documentation": "Type Of Securitisation [domain]" } } }, "auth_ref": [] }, "san_TypesOfAgreementAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TypesOfAgreementAxis", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails", "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Types Of Agreement [Axis]", "label": "Types Of Agreement [Axis]", "documentation": "Types of agreement [axis]" } } }, "auth_ref": [] }, "san_TypesOfAgreementDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TypesOfAgreementDomain", "presentation": [ "http://santander.co.uk/role/REPURCHASEAGREEMENTSNONTRADINGDetails", "http://santander.co.uk/role/REVERSEREPURCHASEAGREEMENTSNONTRADINGDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Types Of Agreement [Domain]", "label": "Types Of Agreement [Domain]", "documentation": "Types of agreement [domain]" } } }, "auth_ref": [] }, "san_TypesOfBranchesAxis": { "xbrltype": "stringItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TypesOfBranchesAxis", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Types Of Branches [Axis]", "label": "Types Of Branches [Axis]", "documentation": "Types Of Branches" } } }, "auth_ref": [] }, "san_TypesOfBranchesDomain": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "TypesOfBranchesDomain", "presentation": [ "http://santander.co.uk/role/PROVISIONSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Types Of Branches [Domain]", "label": "Types Of Branches [Domain]", "documentation": "Types Of Branches [Domain]" } } }, "auth_ref": [] }, "ifrs-full_TypesOfHedgesAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TypesOfHedgesAxis", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Types of hedges [axis]", "label": "Types of hedges [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r124", "r125", "r126", "r231", "r232", "r233" ] }, "ifrs-full_TypesOfHedgesDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "TypesOfHedgesDomain", "presentation": [ "http://santander.co.uk/role/DERIVATIVEFINANCIALINSTRUMENTSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Types of hedges [domain]", "label": "Types of hedges [domain]" } }, "en": { "role": { "documentation": "This member stands for all types of hedges. It also represents the standard value for the 'Types of hedges' axis if no other member is used." } } }, "auth_ref": [ "r124", "r125", "r126", "r231", "r232", "r233" ] }, "san_UKIBanksMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "UKIBanksMember", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "UK&I Banks", "label": "UK&I Banks [Member]", "documentation": "UK&I Banks" } } }, "auth_ref": [] }, "san_UKIrelandMultilateralInterchangeFeesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "UKIrelandMultilateralInterchangeFeesMember", "presentation": [ "http://santander.co.uk/role/CONTINGENTLIABILITIESANDCOMMITMENTSAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "UK&I MIFs", "label": "UK & Ireland Multilateral Interchange Fees [Member]", "documentation": "UK & Ireland Multilateral Interchange Fees" } } }, "auth_ref": [] }, "san_USDollarTwentyBillionCommercialPaperProgrammesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "USDollarTwentyBillionCommercialPaperProgrammesMember", "presentation": [ "http://santander.co.uk/role/DEBTSECURITIESINISSUEDetails" ], "lang": { "en-us": { "role": { "terseLabel": "US $20bn Commercial Paper Programmes", "label": "US Dollar Twenty Billion Commercial Paper Programmes [Member]", "documentation": "US Dollar Twenty Billion Commercial Paper Programmes" } } }, "auth_ref": [] }, "ifrs-full_UndatedSubordinatedLiabilities": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "UndatedSubordinatedLiabilities", "crdr": "credit", "calculation": { "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails": { "parentTag": "ifrs-full_SubordinatedLiabilities", "weight": 1.0, "order": 2.0 } }, "presentation": [ "http://santander.co.uk/role/SUBORDINATEDLIABILITIESScheduleofSubordinatedLiabilitiesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Undated subordinated liabilities", "label": "Undated subordinated liabilities" } }, "en": { "role": { "documentation": "The amount of subordinated liabilities that do not have a specified repayment date. [Refer: Subordinated liabilities]" } } }, "auth_ref": [ "r361" ] }, "san_UnfundedPensionAndPostRetirementMedicalBenefitsMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "UnfundedPensionAndPostRetirementMedicalBenefitsMember", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Unfunded pension and post-retirement medical benefits", "label": "Unfunded Pension And Post Retirement Medical Benefits [Member]", "documentation": "Unfunded Pension And Post Retirement Medical Benefits Member" } } }, "auth_ref": [] }, "ifrs-full_UnobservableInputsAxis": { "xbrltype": "stringItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "UnobservableInputsAxis", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Unobservable inputs [axis]", "label": "Unobservable inputs [axis]" } }, "en": { "role": { "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table." } } }, "auth_ref": [ "r88", "r356" ] }, "ifrs-full_UnobservableInputsDomain": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "UnobservableInputsDomain", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails", "http://santander.co.uk/role/ACQUISITIONOFTSBDisclosureofsignificantunobservableinputsusedinfairvaluemeasurementofassetsDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Unobservable inputs [domain]", "label": "Unobservable inputs [domain]" } }, "en": { "role": { "documentation": "This member stands for all the unobservable inputs. It also represents the standard value for the 'Unobservable inputs' axis if no other member is used." } } }, "auth_ref": [ "r88", "r356" ] }, "ifrs-full_UnusedProvisionReversedOtherProvisions": { "xbrltype": "monetaryItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "UnusedProvisionReversedOtherProvisions", "crdr": "debit", "presentation": [ "http://santander.co.uk/role/PROVISIONSSummaryofProvisionsReconciliationDetails" ], "lang": { "en-us": { "role": { "negatedTerseLabel": "Provisions released", "label": "Unused provision reversed, other provisions" } }, "en": { "role": { "documentation": "The amount reversed for unused other provisions. [Refer: Other provisions]" } } }, "auth_ref": [ "r39", "r203" ] }, "san_UpsideOneScenarioMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "UpsideOneScenarioMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Upside", "label": "Upside One Scenario [member]", "documentation": "Upside one." } } }, "auth_ref": [] }, "ifrs-full_UsefulLifeMeasuredAsPeriodOfTimeIntangibleAssetsOtherThanGoodwill": { "xbrltype": "durationItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "UsefulLifeMeasuredAsPeriodOfTimeIntangibleAssetsOtherThanGoodwill", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Useful life measured as period of time, intangible assets other than goodwill", "label": "Useful life measured as period of time, intangible assets other than goodwill" } }, "en": { "role": { "documentation": "The useful life, measured as period of time, used for intangible assets other than goodwill. [Refer: Intangible assets other than goodwill]" } } }, "auth_ref": [ "r44", "r207" ] }, "san_WeightedScenarioMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "WeightedScenarioMember", "presentation": [ "http://santander.co.uk/role/CreditRiskDisclosureofBaseExpectedCreditLossestoProbabilityWeightedEstimatedCreditLossesDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Weighted", "label": "Weighted Scenario [Member]", "documentation": "7a176e17-4bbb-74d5-8610-bbaef22de075" } } }, "auth_ref": [] }, "san_WholesaleDebtFundingPercentage": { "xbrltype": "percentItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "WholesaleDebtFundingPercentage", "presentation": [ "http://santander.co.uk/role/ACQUISITIONOFTSBAdditionalInformationDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Wholesale debt funding, percentage", "label": "Wholesale Debt Funding, Percentage", "documentation": "Wholesale Debt Funding, Percentage" } } }, "auth_ref": [] }, "ifrs-full_WhollyOrPartlyFundedDefinedBenefitPlansMember": { "xbrltype": "domainItemType", "nsuri": "https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full", "localname": "WhollyOrPartlyFundedDefinedBenefitPlansMember", "presentation": [ "http://santander.co.uk/role/RETIREMENTBENEFITPLANSSummaryofRetirementBenefitPlansDetails" ], "lang": { "en-us": { "role": { "verboseLabel": "Funded defined benefit pension scheme - surplus", "label": "Wholly or partly funded defined benefit plans [member]" } }, "en": { "role": { "documentation": "This member stands for wholly funded or partly funded defined benefit plans. [Refer: Defined benefit plans [domain]]" } } }, "auth_ref": [ "r285" ] }, "san_ZeroAmortisingGuaranteedNotesMember": { "xbrltype": "domainItemType", "nsuri": "http://santander.co.uk/20260630", "localname": "ZeroAmortisingGuaranteedNotesMember", "presentation": [ "http://santander.co.uk/role/OTHERFINANCIALLIABILITIESATFAIRVALUETHROUGHPROFITORLOSSDetails" ], "lang": { "en-us": { "role": { "terseLabel": "Zero Amortising Guaranteed Notes", "label": "Zero Amortising Guaranteed Notes [Member]", "documentation": "Zero Amortising Guaranteed Notes" } } }, "auth_ref": [] } } } }, "std_ref": { "r0": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "10", "IssueDate": "2025-01-01", "Paragraph": "21", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=10&code=ifrs-tx-2025-en-r&anchor=para_21&doctype=Standard", "URIDate": "2025-03-27" }, "r1": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "10", "IssueDate": "2025-01-01", "Section": "Disclosure", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=10&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IAS10_g17-22_TI", "URIDate": "2025-03-27" }, "r2": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "79", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_79&doctype=Standard", "URIDate": "2025-03-27" }, "r3": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "81", "Subparagraph": "ab", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_81_ab&doctype=Standard", "URIDate": "2025-03-27" }, "r4": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "81", "Subparagraph": "c", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_81_c_i&doctype=Standard", "URIDate": "2025-03-27" }, "r5": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "81", "Subparagraph": "c", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_81_c_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r6": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "12", "IssueDate": "2025-01-01", "Section": "Disclosure", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IAS12_g79-88_TI", "URIDate": "2025-03-27" }, "r7": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "73", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_73_d&doctype=Standard", "URIDate": "2025-03-27" }, "r8": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "73", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_73_e&doctype=Standard", "URIDate": "2025-03-27" }, "r9": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "73", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_73&doctype=Standard", "URIDate": "2025-03-27" }, "r10": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "75", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_75_b&doctype=Standard", "URIDate": "2025-03-27" }, "r11": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Section": "Disclosure", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IAS16_g73-79_TI", "URIDate": "2025-03-27" }, "r12": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "138", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_138&doctype=Standard", "URIDate": "2025-03-27" }, "r13": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "140", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_140_a&doctype=Standard", "URIDate": "2025-03-27" }, "r14": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "141", "Subparagraph": "c", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_141_c_i&doctype=Standard", "URIDate": "2025-03-27" }, "r15": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "141", "Subparagraph": "c", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_141_c_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r16": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "141", "Subparagraph": "c", "Clause": "iii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_141_c_iii&doctype=Standard", "URIDate": "2025-03-27" }, "r17": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "141", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_141_c&doctype=Standard", "URIDate": "2025-03-27" }, "r18": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "142", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_142&doctype=Standard", "URIDate": "2025-03-27" }, "r19": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "145", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_145_a&doctype=Standard", "URIDate": "2025-03-27" }, "r20": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "145", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_145_c&doctype=Standard", "URIDate": "2025-03-27" }, "r21": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "145", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_145&doctype=Standard", "URIDate": "2025-03-27" }, "r22": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "53", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_53&doctype=Standard", "URIDate": "2025-03-27" }, "r23": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Section": "Scope", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IAS19_g2-7_TI", "URIDate": "2025-03-27" }, "r24": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "21", "IssueDate": "2025-01-01", "Paragraph": "52", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=21&code=ifrs-tx-2025-en-r&anchor=para_52_b&doctype=Standard", "URIDate": "2025-03-27" }, "r25": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "24", "IssueDate": "2025-01-01", "Paragraph": "19", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=24&code=ifrs-tx-2025-en-r&anchor=para_19&doctype=Standard", "URIDate": "2025-03-27" }, "r26": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "24", "IssueDate": "2025-01-01", "Section": "Disclosures", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=24&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IAS24_g13-24_TI", "URIDate": "2025-03-27" }, "r27": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "26", "IssueDate": "2025-01-01", "Paragraph": "35", "Subparagraph": "b", "Clause": "viii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=26&code=ifrs-tx-2025-en-r&anchor=para_35_b_viii&doctype=Standard", "URIDate": "2025-03-27" }, "r28": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "27", "IssueDate": "2025-01-01", "Paragraph": "16", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=27&code=ifrs-tx-2025-en-r&anchor=para_16_b&doctype=Standard", "URIDate": "2025-03-27" }, "r29": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "27", "IssueDate": "2025-01-01", "Paragraph": "17", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=27&code=ifrs-tx-2025-en-r&anchor=para_17_b&doctype=Standard", "URIDate": "2025-03-27" }, "r30": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "34", "IssueDate": "2025-01-01", "Paragraph": "16A", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=34&code=ifrs-tx-2025-en-r&anchor=para_16A_f&doctype=Standard", "URIDate": "2025-03-27" }, "r31": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "36", "IssueDate": "2025-01-01", "Paragraph": "126", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_126&doctype=Standard", "URIDate": "2025-03-27" }, "r32": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "36", "IssueDate": "2025-01-01", "Paragraph": "130", "Subparagraph": "d", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_130_d_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r33": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "36", "IssueDate": "2025-01-01", "Paragraph": "130", "Subparagraph": "f", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_130_f_i&doctype=Standard", "URIDate": "2025-03-27" }, "r34": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "36", "IssueDate": "2025-01-01", "Paragraph": "134", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_134_a&doctype=Standard", "URIDate": "2025-03-27" }, "r35": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "36", "IssueDate": "2025-01-01", "Paragraph": "134", "Subparagraph": "e", "Clause": "iiA", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_134_e_iiA&doctype=Standard", "URIDate": "2025-03-27" }, "r36": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "36", "IssueDate": "2025-01-01", "Paragraph": "135", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_135_a&doctype=Standard", "URIDate": "2025-03-27" }, "r37": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "84", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_84_b&doctype=Standard", "URIDate": "2025-03-27" }, "r38": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "84", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_84_c&doctype=Standard", "URIDate": "2025-03-27" }, "r39": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "84", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_84_d&doctype=Standard", "URIDate": "2025-03-27" }, "r40": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "84", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_84&doctype=Standard", "URIDate": "2025-03-27" }, "r41": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "86", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_86_a&doctype=Standard", "URIDate": "2025-03-27" }, "r42": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "86", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_86&doctype=Standard", "URIDate": "2025-03-27" }, "r43": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "88", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_88&doctype=Standard", "URIDate": "2025-03-27" }, "r44": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "38", "IssueDate": "2025-01-01", "Paragraph": "118", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2025-en-r&anchor=para_118_a&doctype=Standard", "URIDate": "2025-03-27" }, "r45": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "38", "IssueDate": "2025-01-01", "Paragraph": "118", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2025-en-r&anchor=para_118_c&doctype=Standard", "URIDate": "2025-03-27" }, "r46": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "38", "IssueDate": "2025-01-01", "Paragraph": "118", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2025-en-r&anchor=para_118_e&doctype=Standard", "URIDate": "2025-03-27" }, "r47": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "38", "IssueDate": "2025-01-01", "Paragraph": "118", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2025-en-r&anchor=para_118&doctype=Standard", "URIDate": "2025-03-27" }, "r48": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "39", "IssueDate": "2025-01-01", "Paragraph": "86", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=39&code=ifrs-tx-2025-en-r&anchor=para_86_a&doctype=Standard", "URIDate": "2025-03-27" }, "r49": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "39", "IssueDate": "2025-01-01", "Paragraph": "86", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=39&code=ifrs-tx-2025-en-r&anchor=para_86_b&doctype=Standard", "URIDate": "2025-03-27" }, "r50": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "40", "IssueDate": "2025-01-01", "Paragraph": "32A", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=40&code=ifrs-tx-2025-en-r&anchor=para_32A&doctype=Standard", "URIDate": "2025-03-27" }, "r51": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "40", "IssueDate": "2025-01-01", "Paragraph": "76", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=40&code=ifrs-tx-2025-en-r&anchor=para_76&doctype=Standard", "URIDate": "2025-03-27" }, "r52": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "40", "IssueDate": "2025-01-01", "Paragraph": "79", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=40&code=ifrs-tx-2025-en-r&anchor=para_79_c&doctype=Standard", "URIDate": "2025-03-27" }, "r53": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "40", "IssueDate": "2025-01-01", "Paragraph": "79", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=40&code=ifrs-tx-2025-en-r&anchor=para_79_d&doctype=Standard", "URIDate": "2025-03-27" }, "r54": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "41", "IssueDate": "2025-01-01", "Paragraph": "50", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=41&code=ifrs-tx-2025-en-r&anchor=para_50&doctype=Standard", "URIDate": "2025-03-27" }, "r55": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "41", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=41&code=ifrs-tx-2025-en-r&anchor=para_54_f&doctype=Standard", "URIDate": "2025-03-27" }, "r56": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "10", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_10&doctype=Standard", "URIDate": "2025-03-27" }, "r57": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "20", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_20&doctype=Standard", "URIDate": "2025-03-27" }, "r58": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "25", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_25&doctype=Standard", "URIDate": "2025-03-27" }, "r59": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "28", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_28&doctype=Standard", "URIDate": "2025-03-27" }, "r60": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "39", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_39&doctype=Standard", "URIDate": "2025-03-27" }, "r61": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "40", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_40_a&doctype=Standard", "URIDate": "2025-03-27" }, "r62": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "44H", "Subparagraph": "b", "Clause": "iii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_44H_b_iii&doctype=Standard", "URIDate": "2025-03-27" }, "r63": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "45", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_45&doctype=Standard", "URIDate": "2025-03-27" }, "r64": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "50", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_50_d&doctype=Standard", "URIDate": "2025-03-27" }, "r65": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "f", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28_f_i&doctype=Standard", "URIDate": "2025-03-27" }, "r66": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "29", "Subparagraph": "c", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=8&code=ifrs-tx-2025-en-r&anchor=para_29_c_i&doctype=Standard", "URIDate": "2025-03-27" }, "r67": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "29", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=8&code=ifrs-tx-2025-en-r&anchor=para_29_d&doctype=Standard", "URIDate": "2025-03-27" }, "r68": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "29", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=8&code=ifrs-tx-2025-en-r&anchor=para_29&doctype=Standard", "URIDate": "2025-03-27" }, "r69": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "39", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=8&code=ifrs-tx-2025-en-r&anchor=para_39&doctype=Standard", "URIDate": "2025-03-27" }, "r70": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IAS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "49", "Subparagraph": "b", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=8&code=ifrs-tx-2025-en-r&anchor=para_49_b_i&doctype=Standard", "URIDate": "2025-03-27" }, "r71": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "24", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2025-en-r&anchor=para_24_a&doctype=Standard", "URIDate": "2025-03-27" }, "r72": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "24", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2025-en-r&anchor=para_24_b&doctype=Standard", "URIDate": "2025-03-27" }, "r73": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "32", "Subparagraph": "a", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2025-en-r&anchor=para_32_a_i&doctype=Standard", "URIDate": "2025-03-27" }, "r74": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "32", "Subparagraph": "a", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2025-en-r&anchor=para_32_a_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r75": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "1", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_1&doctype=Standard", "URIDate": "2025-03-27" }, "r76": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "21", "Subparagraph": "b", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_21_b_i&doctype=Standard", "URIDate": "2025-03-27" }, "r77": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "29", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_29_a&doctype=Standard", "URIDate": "2025-03-27" }, "r78": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B12", "Subparagraph": "b", "Clause": "ix", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B12_b_ix&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r79": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B12", "Subparagraph": "b", "Clause": "viii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B12_b_viii&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r80": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B13", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B13_a&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r81": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B13", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B13_e&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r82": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B13", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B13_f&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r83": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B13", "Subparagraph": "g", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B13_g&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r84": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B4", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B4_a&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r85": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_a&doctype=Standard", "URIDate": "2025-03-27" }, "r86": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_b&doctype=Standard", "URIDate": "2025-03-27" }, "r87": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_c&doctype=Standard", "URIDate": "2025-03-27" }, "r88": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_d&doctype=Standard", "URIDate": "2025-03-27" }, "r89": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "e", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_e_i&doctype=Standard", "URIDate": "2025-03-27" }, "r90": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "e", "Clause": "iii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_e_iii&doctype=Standard", "URIDate": "2025-03-27" }, "r91": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_e&doctype=Standard", "URIDate": "2025-03-27" }, "r92": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "h", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_h_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r93": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93&doctype=Standard", "URIDate": "2025-03-27" }, "r94": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "14", "IssueDate": "2025-01-01", "Paragraph": "33", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=14&code=ifrs-tx-2025-en-r&anchor=para_33_b&doctype=Standard", "URIDate": "2025-03-27" }, "r95": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "15", "IssueDate": "2025-01-01", "Paragraph": "113", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2025-en-r&anchor=para_113_a&doctype=Standard", "URIDate": "2025-03-27" }, "r96": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "15", "IssueDate": "2025-01-01", "Paragraph": "114", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2025-en-r&anchor=para_114&doctype=Standard", "URIDate": "2025-03-27" }, "r97": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "15", "IssueDate": "2025-01-01", "Paragraph": "115", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2025-en-r&anchor=para_115&doctype=Standard", "URIDate": "2025-03-27" }, "r98": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "33", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2025-en-r&anchor=para_33&doctype=Standard", "URIDate": "2025-03-27" }, "r99": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "47", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2025-en-r&anchor=para_47_a&doctype=Standard", "URIDate": "2025-03-27" }, "r100": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "53", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2025-en-r&anchor=para_53&doctype=Standard", "URIDate": "2025-03-27" }, "r101": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "95", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2025-en-r&anchor=para_95&doctype=Standard", "URIDate": "2025-03-27" }, "r102": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "17", "IssueDate": "2025-01-01", "Paragraph": "113", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2025-en-r&anchor=para_113_b&doctype=Standard", "URIDate": "2025-03-27" }, "r103": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "17", "IssueDate": "2025-01-01", "Paragraph": "120", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2025-en-r&anchor=para_120&doctype=Standard", "URIDate": "2025-03-27" }, "r104": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "17", "IssueDate": "2025-01-01", "Paragraph": "C32", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2025-en-r&anchor=para_C32&doctype=Appendix&subtype=C", "URIDate": "2025-03-27" }, "r105": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "2", "IssueDate": "2025-01-01", "Paragraph": "45", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2025-en-r&anchor=para_45_d&doctype=Standard", "URIDate": "2025-03-27" }, "r106": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_c&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r107": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_f&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r108": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "h", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_h_i&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r109": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "h", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_h_ii&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r110": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "h", "Clause": "iii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_h_iii&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r111": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "m", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_m&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r112": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "q", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_q_i&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r113": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "q", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_q_ii&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r114": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r115": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B67", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B67_c&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r116": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B67", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B67_d&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r117": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B67", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B67&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r118": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Section": "Disclosures", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IFRS03_g59-63_TI", "URIDate": "2025-03-27" }, "r119": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Section": "Disclosures application of paragraphs 59 and 61", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&doctype=Appendix&subtype=B&dita_xref=IFRS03_gB64-B67_TI", "URIDate": "2025-03-27" }, "r120": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "5", "IssueDate": "2025-01-01", "Paragraph": "33", "Subparagraph": "b", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2025-en-r&anchor=para_33_b_i&doctype=Standard", "URIDate": "2025-03-27" }, "r121": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "5", "IssueDate": "2025-01-01", "Paragraph": "38", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2025-en-r&anchor=para_38&doctype=Standard", "URIDate": "2025-03-27" }, "r122": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "14", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_14_a&doctype=Standard", "URIDate": "2025-03-27" }, "r123": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "20", "Subparagraph": "a", "Clause": "viii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_20_a_viii&doctype=Standard", "URIDate": "2025-03-27" }, "r124": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "24A", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_24A&doctype=Standard", "URIDate": "2025-03-27" }, "r125": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "24B", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_24B&doctype=Standard", "URIDate": "2025-03-27" }, "r126": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "24C", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_24C&doctype=Standard", "URIDate": "2025-03-27" }, "r127": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "25", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_25&doctype=Standard", "URIDate": "2025-03-27" }, "r128": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35H", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35H_a&doctype=Standard", "URIDate": "2025-03-27" }, "r129": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35H", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35H_b&doctype=Standard", "URIDate": "2025-03-27" }, "r130": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35H", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35H_c&doctype=Standard", "URIDate": "2025-03-27" }, "r131": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35H", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35H&doctype=Standard", "URIDate": "2025-03-27" }, "r132": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35I", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35I&doctype=Standard", "URIDate": "2025-03-27" }, "r133": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35K", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35K&doctype=Standard", "URIDate": "2025-03-27" }, "r134": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35M", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35M_a&doctype=Standard", "URIDate": "2025-03-27" }, "r135": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35M", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35M_b&doctype=Standard", "URIDate": "2025-03-27" }, "r136": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35M", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35M_c&doctype=Standard", "URIDate": "2025-03-27" }, "r137": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35M", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35M&doctype=Standard", "URIDate": "2025-03-27" }, "r138": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "36", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_36&doctype=Standard", "URIDate": "2025-03-27" }, "r139": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "42I", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_42I&doctype=Standard", "URIDate": "2025-03-27" }, "r140": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "6", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_6&doctype=Standard", "URIDate": "2025-03-27" }, "r141": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "7", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_7&doctype=Standard", "URIDate": "2025-03-27" }, "r142": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "8", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_8_a&doctype=Standard", "URIDate": "2025-03-27" }, "r143": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "8", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_8_e&doctype=Standard", "URIDate": "2025-03-27" }, "r144": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "8", "Subparagraph": "g", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_8_g&doctype=Standard", "URIDate": "2025-03-27" }, "r145": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "8", "Subparagraph": "h", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_8_h&doctype=Standard", "URIDate": "2025-03-27" }, "r146": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "8", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_8&doctype=Standard", "URIDate": "2025-03-27" }, "r147": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "B2", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_B2_a&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r148": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "B8E", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_B8E&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r149": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Section": "Credit risk", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IFRS07_g35A-38_TI", "URIDate": "2025-03-27" }, "r150": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Section": "Scope", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IFRS07_g3-5A_TI", "URIDate": "2025-03-27" }, "r151": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "23", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_23_c&doctype=Standard", "URIDate": "2025-03-27" }, "r152": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "23", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_23_d&doctype=Standard", "URIDate": "2025-03-27" }, "r153": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "23", "Subparagraph": "h", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_23_h&doctype=Standard", "URIDate": "2025-03-27" }, "r154": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "23", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_23&doctype=Standard", "URIDate": "2025-03-27" }, "r155": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28_b&doctype=Standard", "URIDate": "2025-03-27" }, "r156": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28_c&doctype=Standard", "URIDate": "2025-03-27" }, "r157": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28_d&doctype=Standard", "URIDate": "2025-03-27" }, "r158": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28_e&doctype=Standard", "URIDate": "2025-03-27" }, "r159": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28&doctype=Standard", "URIDate": "2025-03-27" }, "r160": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Section": "Disclosure", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&doctype=Standard&dita_xref=IFRS08_g20-24_TI", "URIDate": "2025-03-27" }, "r161": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "9", "IssueDate": "2025-01-01", "Paragraph": "6.5.11", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2025-en-r&anchor=para_6.5.11&doctype=Standard", "URIDate": "2025-03-27" }, "r162": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "9", "IssueDate": "2025-01-01", "Paragraph": "6.5.15", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2025-en-r&anchor=para_6.5.15&doctype=Standard", "URIDate": "2025-03-27" }, "r163": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "9", "IssueDate": "2025-01-01", "Paragraph": "7.2.34", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2025-en-r&anchor=para_7.2.34&doctype=Standard", "URIDate": "2025-03-27" }, "r164": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Name": "IFRS", "Number": "9", "IssueDate": "2025-01-01", "Paragraph": "7.2.42", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2025-en-r&anchor=para_7.2.42&doctype=Standard", "URIDate": "2025-03-27" }, "r165": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2026-01-01", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "20B", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_20B&doctype=Standard", "URIDate": "2025-03-27" }, "r166": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "103", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_103&doctype=Standard", "URIDate": "2025-03-27" }, "r167": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "104", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_104&doctype=Standard", "URIDate": "2025-03-27" }, "r168": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "115", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_115&doctype=Standard", "URIDate": "2025-03-27" }, "r169": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "133", "Subparagraph": "a", "Clause": "iii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_133_a_iii&doctype=Standard", "URIDate": "2025-03-27" }, "r170": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "133", "Subparagraph": "a", "Clause": "iv", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_133_a_iv&doctype=Standard", "URIDate": "2025-03-27" }, "r171": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "138", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_138&doctype=Standard", "URIDate": "2025-03-27" }, "r172": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "168", "Subparagraph": "b", "Clause": "iii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_168_b_iii&doctype=Standard", "URIDate": "2025-03-27" }, "r173": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "169", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_169&doctype=Standard", "URIDate": "2025-03-27" }, "r174": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "176", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_176&doctype=Standard", "URIDate": "2025-03-27" }, "r175": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "178", "Subparagraph": "f", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_178_f_i&doctype=Standard", "URIDate": "2025-03-27" }, "r176": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "179", "Subparagraph": "c", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_179_c_i&doctype=Standard", "URIDate": "2025-03-27" }, "r177": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "179", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_179_d&doctype=Standard", "URIDate": "2025-03-27" }, "r178": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "179", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_179&doctype=Standard", "URIDate": "2025-03-27" }, "r179": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "184", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_184&doctype=Standard", "URIDate": "2025-03-27" }, "r180": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "186", "Subparagraph": "b", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_186_b_i&doctype=Standard", "URIDate": "2025-03-27" }, "r181": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "190", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_190&doctype=Standard", "URIDate": "2025-03-27" }, "r182": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "192", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_192&doctype=Standard", "URIDate": "2025-03-27" }, "r183": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "194", "Subparagraph": "c", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_194_c_i&doctype=Standard", "URIDate": "2025-03-27" }, "r184": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "194", "Subparagraph": "c", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_194_c_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r185": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "200", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_200_d&doctype=Standard", "URIDate": "2025-03-27" }, "r186": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "200", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_200_e&doctype=Standard", "URIDate": "2025-03-27" }, "r187": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "200", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_200&doctype=Standard", "URIDate": "2025-03-27" }, "r188": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "203", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_203&doctype=Standard", "URIDate": "2025-03-27" }, "r189": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "204", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_204&doctype=Standard", "URIDate": "2025-03-27" }, "r190": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "206", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_206_a&doctype=Standard", "URIDate": "2025-03-27" }, "r191": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "207", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_207_c&doctype=Standard", "URIDate": "2025-03-27" }, "r192": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "218", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_218_b&doctype=Standard", "URIDate": "2025-03-27" }, "r193": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "231", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_231&doctype=Standard", "URIDate": "2025-03-27" }, "r194": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "24", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_24_a&doctype=Standard", "URIDate": "2025-03-27" }, "r195": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "24", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_24_b&doctype=Standard", "URIDate": "2025-03-27" }, "r196": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "246", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_246_f&doctype=Standard", "URIDate": "2025-03-27" }, "r197": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "250", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_250&doctype=Standard", "URIDate": "2025-03-27" }, "r198": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "254", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_254_a&doctype=Standard", "URIDate": "2025-03-27" }, "r199": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "254", "Subparagraph": "e", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_254_e_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r200": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "255", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_255_a&doctype=Standard", "URIDate": "2025-03-27" }, "r201": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "257", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_257_b&doctype=Standard", "URIDate": "2025-03-27" }, "r202": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "257", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_257_c&doctype=Standard", "URIDate": "2025-03-27" }, "r203": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "257", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_257_d&doctype=Standard", "URIDate": "2025-03-27" }, "r204": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "257", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_257&doctype=Standard", "URIDate": "2025-03-27" }, "r205": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "259", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_259_a&doctype=Standard", "URIDate": "2025-03-27" }, "r206": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "259", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_259&doctype=Standard", "URIDate": "2025-03-27" }, "r207": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "263", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_263_a&doctype=Standard", "URIDate": "2025-03-27" }, "r208": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "263", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_263_c&doctype=Standard", "URIDate": "2025-03-27" }, "r209": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "263", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_263_e&doctype=Standard", "URIDate": "2025-03-27" }, "r210": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "263", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_263&doctype=Standard", "URIDate": "2025-03-27" }, "r211": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "269", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_269&doctype=Standard", "URIDate": "2025-03-27" }, "r212": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "271", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_271_c&doctype=Standard", "URIDate": "2025-03-27" }, "r213": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "271", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_271_d&doctype=Standard", "URIDate": "2025-03-27" }, "r214": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "273", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_273&doctype=Standard", "URIDate": "2025-03-27" }, "r215": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "274", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_274_e&doctype=Standard", "URIDate": "2025-03-27" }, "r216": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "a", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_28_a_i&doctype=Standard", "URIDate": "2025-03-27" }, "r217": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "a", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_28_a_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r218": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "35", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_35_c&doctype=Standard", "URIDate": "2025-03-27" }, "r219": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "35", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_35_e&doctype=Standard", "URIDate": "2025-03-27" }, "r220": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "35", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_35&doctype=Standard", "URIDate": "2025-03-27" }, "r221": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "37", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_37&doctype=Standard", "URIDate": "2025-03-27" }, "r222": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "43", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_43&doctype=Standard", "URIDate": "2025-03-27" }, "r223": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "44", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_44_a&doctype=Standard", "URIDate": "2025-03-27" }, "r224": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "44", "Subparagraph": "b", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_44_b_i&doctype=Standard", "URIDate": "2025-03-27" }, "r225": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "44", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_44_d&doctype=Standard", "URIDate": "2025-03-27" }, "r226": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "44", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_44_e&doctype=Standard", "URIDate": "2025-03-27" }, "r227": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "44", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_44&doctype=Standard", "URIDate": "2025-03-27" }, "r228": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "51", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_51_a&doctype=Standard", "URIDate": "2025-03-27" }, "r229": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "56", "Subparagraph": "a", "Clause": "v", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_56_a_v&doctype=Standard", "URIDate": "2025-03-27" }, "r230": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "56A", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_56A&doctype=Standard", "URIDate": "2025-03-27" }, "r231": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "60", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_60&doctype=Standard", "URIDate": "2025-03-27" }, "r232": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "61", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_61&doctype=Standard", "URIDate": "2025-03-27" }, "r233": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "62", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_62&doctype=Standard", "URIDate": "2025-03-27" }, "r234": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "66", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_66_a&doctype=Standard", "URIDate": "2025-03-27" }, "r235": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "66", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_66_b&doctype=Standard", "URIDate": "2025-03-27" }, "r236": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "66", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_66_c&doctype=Standard", "URIDate": "2025-03-27" }, "r237": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "66", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_66&doctype=Standard", "URIDate": "2025-03-27" }, "r238": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "67", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_67&doctype=Standard", "URIDate": "2025-03-27" }, "r239": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "70", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_70&doctype=Standard", "URIDate": "2025-03-27" }, "r240": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "71", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_71_a&doctype=Standard", "URIDate": "2025-03-27" }, "r241": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "71", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_71_b&doctype=Standard", "URIDate": "2025-03-27" }, "r242": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "71", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_71_c&doctype=Standard", "URIDate": "2025-03-27" }, "r243": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "71", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_71&doctype=Standard", "URIDate": "2025-03-27" }, "r244": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "75", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_75_a&doctype=Standard", "URIDate": "2025-03-27" }, "r245": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "88", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_88_a&doctype=Standard", "URIDate": "2025-03-27" }, "r246": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "95", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_95_a&doctype=Standard", "URIDate": "2025-03-27" }, "r247": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "95", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_95_b&doctype=Standard", "URIDate": "2025-03-27" }, "r248": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "95", "Subparagraph": "d", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_95_d_i&doctype=Standard", "URIDate": "2025-03-27" }, "r249": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "95", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_95&doctype=Standard", "URIDate": "2025-03-27" }, "r250": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "B12", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_B12&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r251": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "B13", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_B13&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r252": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "B9", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_B9_f&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r253": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expired 2023-01-01", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "22", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_22&doctype=Standard", "URIDate": "2025-03-27" }, "r254": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2026-01-01", "Name": "IFRS", "Number": "9", "IssueDate": "2025-01-01", "Paragraph": "7.2.49", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2025-en-r&anchor=para_7.2.49&doctype=Standard", "URIDate": "2025-03-27" }, "r255": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "104", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_104&doctype=Standard", "URIDate": "2025-03-27" }, "r256": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "106", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_106_a&doctype=Standard", "URIDate": "2025-03-27" }, "r257": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "106", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_106_b&doctype=Standard", "URIDate": "2025-03-27" }, "r258": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "106", "Subparagraph": "d", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_106_d_i&doctype=Standard", "URIDate": "2025-03-27" }, "r259": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "106", "Subparagraph": "d", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_106_d_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r260": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "106", "Subparagraph": "d", "Clause": "iii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_106_d_iii&doctype=Standard", "URIDate": "2025-03-27" }, "r261": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "106", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_106&doctype=Standard", "URIDate": "2025-03-27" }, "r262": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "107", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_107&doctype=Standard", "URIDate": "2025-03-27" }, "r263": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "117", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_117&doctype=Standard", "URIDate": "2025-03-27" }, "r264": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_b&doctype=Standard", "URIDate": "2025-03-27" }, "r265": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_c&doctype=Standard", "URIDate": "2025-03-27" }, "r266": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_i&doctype=Standard", "URIDate": "2025-03-27" }, "r267": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "l", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_l&doctype=Standard", "URIDate": "2025-03-27" }, "r268": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "n", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_n&doctype=Standard", "URIDate": "2025-03-27" }, "r269": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "55", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_55&doctype=Standard", "URIDate": "2025-03-27" }, "r270": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "7", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_7&doctype=Standard", "URIDate": "2025-03-27" }, "r271": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "78", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78_e&doctype=Standard", "URIDate": "2025-03-27" }, "r272": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "81A", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_81A_a&doctype=Standard", "URIDate": "2025-03-27" }, "r273": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "81A", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_81A_b&doctype=Standard", "URIDate": "2025-03-27" }, "r274": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "81A", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_81A_c&doctype=Standard", "URIDate": "2025-03-27" }, "r275": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "82", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_82_d&doctype=Standard", "URIDate": "2025-03-27" }, "r276": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "90", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_90&doctype=Standard", "URIDate": "2025-03-27" }, "r277": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "91", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_91_a&doctype=Standard", "URIDate": "2025-03-27" }, "r278": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "91", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_91_b&doctype=Standard", "URIDate": "2025-03-27" }, "r279": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "92", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_92&doctype=Standard", "URIDate": "2025-03-27" }, "r280": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "98", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_98_f&doctype=Standard", "URIDate": "2025-03-27" }, "r281": { "role": "http://www.xbrl.org/2003/role/disclosureRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "99", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_99&doctype=Standard", "URIDate": "2025-03-27" }, "r282": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "37", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_37_b&doctype=Standard", "URIDate": "2025-03-27" }, "r283": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "37", "Subparagraph": "h", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_37_h&doctype=Standard", "URIDate": "2025-03-27" }, "r284": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "138", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_138_d&doctype=Standard", "URIDate": "2025-03-27" }, "r285": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "138", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_138_e&doctype=Standard", "URIDate": "2025-03-27" }, "r286": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "70", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_70&doctype=Standard", "URIDate": "2025-03-27" }, "r287": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "87", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_87&doctype=Standard", "URIDate": "2025-03-27" }, "r288": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Section": "Example 10 A court case", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&doctype=Illustrative%20Examples&dita_xref=IAS37_IE_C_ex10_TI", "URIDate": "2025-03-27" }, "r289": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "38", "IssueDate": "2025-01-01", "Paragraph": "119", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2025-en-r&anchor=para_119_a&doctype=Standard", "URIDate": "2025-03-27" }, "r290": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "38", "IssueDate": "2025-01-01", "Paragraph": "119", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2025-en-r&anchor=para_119_c&doctype=Standard", "URIDate": "2025-03-27" }, "r291": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "17", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_17_a&doctype=Standard", "URIDate": "2025-03-27" }, "r292": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "17", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_17_e&doctype=Standard", "URIDate": "2025-03-27" }, "r293": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Section": "A Statement of cash flows for an entity other than a financial institution", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&doctype=Illustrative%20Examples&dita_xref=IAS07_IE_A_TI", "URIDate": "2025-03-27" }, "r294": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "B10", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2025-en-r&anchor=para_B10_b&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r295": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "94", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_94&doctype=Standard", "URIDate": "2025-03-27" }, "r296": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "B6", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_B6&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r297": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "IE60", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_IE60&doctype=Illustrative%20Examples", "URIDate": "2025-03-27" }, "r298": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "IE63", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_IE63&doctype=Illustrative%20Examples", "URIDate": "2025-03-27" }, "r299": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "17", "IssueDate": "2025-01-01", "Paragraph": "113", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2025-en-r&anchor=para_113_b&doctype=Standard", "URIDate": "2025-03-27" }, "r300": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "17", "IssueDate": "2025-01-01", "Paragraph": "96", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2025-en-r&anchor=para_96_c&doctype=Standard", "URIDate": "2025-03-27" }, "r301": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_i&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r302": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r303": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "IE72", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_IE72&doctype=Illustrative%20Examples", "URIDate": "2025-03-27" }, "r304": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "13C", "Subparagraph": "d", "Clause": "ii", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_13C_d_ii&doctype=Standard", "URIDate": "2025-03-27" }, "r305": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35H", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35H&doctype=Standard", "URIDate": "2025-03-27" }, "r306": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35I", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35I_a&doctype=Standard", "URIDate": "2025-03-27" }, "r307": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35I", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35I_c&doctype=Standard", "URIDate": "2025-03-27" }, "r308": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35I", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35I_d&doctype=Standard", "URIDate": "2025-03-27" }, "r309": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35I", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35I&doctype=Standard", "URIDate": "2025-03-27" }, "r310": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35N", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35N&doctype=Standard", "URIDate": "2025-03-27" }, "r311": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "6", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_6&doctype=Standard", "URIDate": "2025-03-27" }, "r312": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "B33", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_B33&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r313": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "IG20B", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_IG20B&doctype=Implementation%20Guidance", "URIDate": "2025-03-27" }, "r314": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "IG40B", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_IG40B&doctype=Implementation%20Guidance", "URIDate": "2025-03-27" }, "r315": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "IG40D", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_IG40D&doctype=Implementation%20Guidance", "URIDate": "2025-03-27" }, "r316": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "23", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_23&doctype=Standard", "URIDate": "2025-03-27" }, "r317": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28_b&doctype=Standard", "URIDate": "2025-03-27" }, "r318": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "28", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_28&doctype=Standard", "URIDate": "2025-03-27" }, "r319": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Name": "IFRS", "Number": "8", "IssueDate": "2025-01-01", "Paragraph": "IG4", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2025-en-r&anchor=para_IG4&doctype=Implementation%20Guidance", "URIDate": "2025-03-27" }, "r320": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "35", "Subparagraph": "g", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_35_g&doctype=Standard", "URIDate": "2025-03-27" }, "r321": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "35", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_35&doctype=Standard", "URIDate": "2025-03-27" }, "r322": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "66", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_66&doctype=Standard", "URIDate": "2025-03-27" }, "r323": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "70", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_70_a&doctype=Standard", "URIDate": "2025-03-27" }, "r324": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "70", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_70_c&doctype=Standard", "URIDate": "2025-03-27" }, "r325": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "70", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_70_d&doctype=Standard", "URIDate": "2025-03-27" }, "r326": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "70", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_70&doctype=Standard", "URIDate": "2025-03-27" }, "r327": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "B9", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_B9_b&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r328": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Effective 2027-01-01", "Name": "IFRS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "B9", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_B9_f&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r329": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "102", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_102&doctype=Standard", "URIDate": "2025-03-27" }, "r330": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "103", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_103&doctype=Standard", "URIDate": "2025-03-27" }, "r331": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "108", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_108&doctype=Standard", "URIDate": "2025-03-27" }, "r332": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "78", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78_b&doctype=Standard", "URIDate": "2025-03-27" }, "r333": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "78", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78_e&doctype=Standard", "URIDate": "2025-03-27" }, "r334": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "82A", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_82A&doctype=Standard", "URIDate": "2025-03-27" }, "r335": { "role": "http://www.xbrl.org/2003/role/exampleRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "IG6", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_IG6&doctype=Implementation%20Guidance", "URIDate": "2025-03-27" }, "r336": { "role": "http://www.xbrl.org/2003/role/presentationRef", "Publisher": "SEC", "Name": "Exchange Act", "Number": "240", "Section": "12", "Subsection": "b-2" }, "r337": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "12", "IssueDate": "2025-01-01", "Paragraph": "81", "Subparagraph": "g", "Clause": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_81_g_i&doctype=Standard", "URIDate": "2025-03-27" }, "r338": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "73", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_73_d&doctype=Standard", "URIDate": "2025-03-27" }, "r339": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "16", "IssueDate": "2025-01-01", "Paragraph": "73", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_73_e&doctype=Standard", "URIDate": "2025-03-27" }, "r340": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "135", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_135_b&doctype=Standard", "URIDate": "2025-03-27" }, "r341": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "141", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_141_c&doctype=Standard", "URIDate": "2025-03-27" }, "r342": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "144", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_144&doctype=Standard", "URIDate": "2025-03-27" }, "r343": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "145", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_145&doctype=Standard", "URIDate": "2025-03-27" }, "r344": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "5", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_5&doctype=Standard", "URIDate": "2025-03-27" }, "r345": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "19", "IssueDate": "2025-01-01", "Paragraph": "57", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_57_a&doctype=Standard", "URIDate": "2025-03-27" }, "r346": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "84", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_84&doctype=Standard", "URIDate": "2025-03-27" }, "r347": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "37", "IssueDate": "2025-01-01", "Paragraph": "88", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_88&doctype=Standard", "URIDate": "2025-03-27" }, "r348": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "38", "IssueDate": "2025-01-01", "Paragraph": "118", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2025-en-r&anchor=para_118_c&doctype=Standard", "URIDate": "2025-03-27" }, "r349": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "40", "IssueDate": "2025-01-01", "Paragraph": "79", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=40&code=ifrs-tx-2025-en-r&anchor=para_79_c&doctype=Standard", "URIDate": "2025-03-27" }, "r350": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "41", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "f", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=41&code=ifrs-tx-2025-en-r&anchor=para_54_f&doctype=Standard", "URIDate": "2025-03-27" }, "r351": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "16", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_16&doctype=Standard", "URIDate": "2025-03-27" }, "r352": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "17", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_17&doctype=Standard", "URIDate": "2025-03-27" }, "r353": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "20", "Subparagraph": "b", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_20_b&doctype=Standard", "URIDate": "2025-03-27" }, "r354": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IAS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "35", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2025-en-r&anchor=para_35&doctype=Standard", "URIDate": "2025-03-27" }, "r355": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_d&doctype=Standard", "URIDate": "2025-03-27" }, "r356": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IFRS", "Number": "13", "IssueDate": "2025-01-01", "Paragraph": "93", "Subparagraph": "h", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2025-en-r&anchor=para_93_h&doctype=Standard", "URIDate": "2025-03-27" }, "r357": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IFRS", "Number": "3", "IssueDate": "2025-01-01", "Paragraph": "B64", "Subparagraph": "i", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B64_i&doctype=Appendix&subtype=B", "URIDate": "2025-03-27" }, "r358": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Name": "IFRS", "Number": "7", "IssueDate": "2025-01-01", "Paragraph": "7", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_7&doctype=Standard", "URIDate": "2025-03-27" }, "r359": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "10", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_10_e&doctype=Standard", "URIDate": "2025-03-27" }, "r360": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "108", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_108&doctype=Standard", "URIDate": "2025-03-27" }, "r361": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "112", "Subparagraph": "c", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_112_c&doctype=Standard", "URIDate": "2025-03-27" }, "r362": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "20", "Subparagraph": "d", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_20_d&doctype=Standard", "URIDate": "2025-03-27" }, "r363": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "54", "Subparagraph": "a", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_a&doctype=Standard", "URIDate": "2025-03-27" }, "r364": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "55", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_55&doctype=Standard", "URIDate": "2025-03-27" }, "r365": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "78", "Subparagraph": "e", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78_e&doctype=Standard", "URIDate": "2025-03-27" }, "r366": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "78", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78&doctype=Standard", "URIDate": "2025-03-27" }, "r367": { "role": "http://www.xbrl.org/2009/role/commonPracticeRef", "Note": "Expiry date 2027-01-01", "Name": "IAS", "Number": "1", "IssueDate": "2025-01-01", "Paragraph": "85", "URI": "https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_85&doctype=Standard", "URIDate": "2025-03-27" } } }