Dividends on ordinary shares and preference shares - Narrative (Details) £ in Millions	Jul. 28, 2025 GBP (£)
Ordinary shares \| Dividend declaration
Disclosure of non-adjusting events after reporting period [line items]
Dividends proposed or declared before financial statements authorised for issue but not recognised as distribution to owners	£ 1,375

The amount of dividends proposed or declared after the reporting period but before financial statements are authorised for issue. Such dividends are not recognised as a liability at the end of the reporting period because no obligation exists at that time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 10
-IssueDate 2024-01-01
-Paragraph 13
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=10&code=ifrs-tx-2024-en-r&anchor=para_13&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 137
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_137_a&doctype=Standard
-URIDate 2024-03-27

Name:	ifrs-full_DividendsProposedOrDeclaredBeforeFinancialStatementsAuthorisedForIssueButNotRecognisedAsDistributionToOwners
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration