Name:	ifrs-full_DisclosureOfFinancialAssetsLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of receivables related to finance leases.

Reference 1: 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

Name:	ifrs-full_FinanceLeaseReceivables
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of interest recognised as a receivable.

Reference 1: 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

Name:	ifrs-full_InterestReceivable
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of an entity’s right to consideration in exchange for goods or services that the entity has transferred to a customer that is unconditional. A right to consideration is unconditional if only the passage of time is required before payment of that consideration is due.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2025-01-01
-Paragraph 105
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2025-en-r&anchor=para_105&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2025-01-01
-Paragraph 116
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2025-en-r&anchor=para_116_a&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 105
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_105_a&doctype=Standard
-URIDate 2025-03-27

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 105
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_105_a&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_ReceivablesFromContractsWithCustomers
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of instruments representing indebtedness measured at amortized cost held by the entity.

No definition available.

Name:	ubsag_DebtInstrumentsHeldMeasuredAtAmortizedCost
Namespace Prefix:	ubsag_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of other financial assets that are held at amortized cost.

No definition available.

Name:	ubsag_OtherFinancialAssetsAtAmortisedCost
Namespace Prefix:	ubsag_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of other miscellaneous financial assets that are held at amortized cost.

No definition available.

Name:	ubsag_OtherFinancialAssetsAtAmortisedCostMiscellaneous
Namespace Prefix:	ubsag_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of recruitment loans to financial advisors.

No definition available.

Name:	ubsag_RecruitmentLoansToFinancialAdvisors
Namespace Prefix:	ubsag_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of receivables in settlement and clearing accounts.

No definition available.