Derivative Financial Instruments - Impact of Derivatives on Consolidated Statement of Income (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ 156	$ 180	$ 485	$ 601
Foreign exchange contracts | Foreign exchange trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	198	207	621	676
Foreign exchange contracts | Interest expense
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(24)	(16)	(40)	0
Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(3)	0	(2)	0
Other derivative contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income		$ (11)		$ (75)
Other derivative contracts | Other fee revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	6		5
Other derivative contracts | Compensation and employee benefits
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ (21)		$ (99)