Debt issued measured at amortized cost (Narrative) (Detail) - USD ($) $ in Billions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Debt Issued Held At Amortized Cost [Line Items]
Hedge accounting impact on carrying amount	$ (3.0)	$ (6.1)

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

No definition available.

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Namespace Prefix:	ubs_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration