Reclassification of financial assets (Narrative) (Detail) $ in Millions	3 Months Ended
Jun. 30, 2023 USD ($)
Disclosure Of Reclassification Of Financial Assets [Line Items]
Reclassification of financial assets to Other financial assets measured at amortized cost, before tax	$ 449
Reclassification of financial assets to Other financial assets measured at amortized cost, net of tax	$ 333

The gains (losses) recognised in other comprehensive income related to reclassification of financial assets out of measured at fair value through other comprehensive income category into measured at amortised cost category, before tax.

No definition available.

Name:	ubs_GainsLossesOnFinancialAssetsReclassifiedOutOfMeasuredAtFairValuethroughOtherComprehensiveIncomeIntoMeasuredAtAmortisedCostBeforeTax
Namespace Prefix:	ubs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration