v3.26.1
FVM - Level 3 instruments: Sensitivity to changes in unobservable input assumptions (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes $ 1,567 $ 1,710
Unfavorable changes (1,389) (1,452)
Loans at fair value (held for trading and not held for trading) and guarantees    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 32 79
Unfavorable changes (49) (67)
Securities financing transactions    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 14 16
Unfavorable changes (22) (8)
Auction rate securities    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 0 8
Unfavorable changes 0 (4)
Asset-backed securities    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 19 15
Unfavorable changes (15) (15)
Equity instruments    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 194 414
Unfavorable changes (194) (389)
Investment fund units    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 180 204
Unfavorable changes (181) (206)
Loan commitments measured at FVTPL    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 16 15
Unfavorable changes (26) (25)
Interest rate derivative contracts, net    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 31 52
Unfavorable changes (24) (23)
Credit derivatives, net    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 23 25
Unfavorable changes (49) (55)
Foreign exchange derivatives, net    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 6 9
Unfavorable changes (5) (6)
Equity / index derivatives, net    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 809 667
Unfavorable changes (705) (570)
Other    
Disclosure Of Sensitivity Analysis Of Fair Value Measurement To Changes In Unobservable Inputs Assets And Liabilities [Line Items]    
Favorable changes 242 206
Unfavorable changes $ (119) $ (83)