v3.25.2
Fair values of financial instruments carried at fair value - Sensitivity of Level 3 fair values to reasonably possible alternative assumptions (Details) - USD ($)
$ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]      
Favourable changes reflected in profit or loss $ 2,416 $ 2,228 $ 1,936
Unfavourable changes reflected in profit or loss (1,798) (1,582) (1,475)
Favourable changes reflected in OCI 52 42 47
Unfavourable changes reflected in OCI $ (55) (45) (50)
Confidence level 95.00%    
Derivatives, trading assets and trading liabilities | Derivatives, trading liabilities      
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]      
Favourable changes reflected in profit or loss $ 524 546 481
Unfavourable changes reflected in profit or loss (309) (309) (313)
Favourable changes reflected in OCI 0 0 0
Unfavourable changes reflected in OCI 0 0 0
Financial assets designated and otherwise mandatorily measured at fair value through profit or loss | Financial liabilities designated at fair value      
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]      
Favourable changes reflected in profit or loss 1,873 1,664 1,434
Unfavourable changes reflected in profit or loss (1,470) (1,255) (1,141)
Favourable changes reflected in OCI 0 0 0
Unfavourable changes reflected in OCI 0 0 0
Financial investments      
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]      
Favourable changes reflected in profit or loss 19 18 21
Unfavourable changes reflected in profit or loss (19) (18) (21)
Favourable changes reflected in OCI 52 42 47
Unfavourable changes reflected in OCI $ (55) $ (45) $ (50)