Derivative Financial Instruments - Notional Value of Derivative Contracts (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Total	$ 1,503,839	$ 1,307,707
Interest rate contracts
Derivative [Line Items]
Total	149,968	123,726
Futures and forwards
Derivative [Line Items]
Total	28,759	16,829
Swaps
Derivative [Line Items]
Total	120,114	104,458
Options written
Derivative [Line Items]
Total	546	1,217
Options purchased
Derivative [Line Items]
Total	549	1,222
Foreign exchange contracts
Derivative [Line Items]
Total	1,290,035	1,118,248
Swaps, futures and forwards
Derivative [Line Items]
Total	1,179,717	1,026,047
Options written
Derivative [Line Items]
Total	29,873	29,739
Options purchased
Derivative [Line Items]
Total	30,149	29,859
Spot
Derivative [Line Items]
Total	50,296	32,603
Total commodities, equities and precious metals
Derivative [Line Items]
Total	46,899	44,888
Swaps, futures and forwards
Derivative [Line Items]
Total	34,005	33,520
Options written
Derivative [Line Items]
Total	1,747	1,513
Options purchased
Derivative [Line Items]
Total	11,147	9,855
Credit derivatives
Derivative [Line Items]
Total	15,157	19,175
Other Contracts
Derivative [Line Items]
Total	$ 1,780	$ 1,670