Derivative Financial Instruments - Notional Value of Derivative Contracts (Detail) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Derivative [Line Items]
Total	$ 1,717,600	$ 1,405,200
Interest rate contracts
Derivative [Line Items]
Total	192,500	137,300
Swaps, futures and forwards
Derivative [Line Items]
Total	191,700	137,200
Options written
Derivative [Line Items]
Total	400	100
Options purchased
Derivative [Line Items]
Total	400	0
Foreign exchange contracts
Derivative [Line Items]
Total	1,444,800	1,195,200
Swaps, futures and forwards
Derivative [Line Items]
Total	1,349,000	1,113,200
Options written
Derivative [Line Items]
Total	21,900	23,800
Options purchased
Derivative [Line Items]
Total	22,000	23,800
Spot
Derivative [Line Items]
Total	51,900	34,400
Total commodities, equities and precious metals
Derivative [Line Items]
Total	54,600	48,400
Swaps, futures and forwards
Derivative [Line Items]
Total	38,000	35,800
Options written
Derivative [Line Items]
Total	3,300	1,700
Options purchased
Derivative [Line Items]
Total	13,300	10,900
Credit derivatives
Derivative [Line Items]
Total	23,900	22,500
Other Contracts
Derivative [Line Items]
Total	$ 1,800	$ 1,800