Derivative Financial Instruments - Impact of Derivatives on Consolidated Statement of Income (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ 204	$ 184
Foreign exchange contracts | Foreign exchange trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	239	242
Foreign exchange contracts | Interest expense
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	13	21
Interest rate contracts | Foreign exchange trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	6	0
Other derivative contracts | Compensation and employee benefits
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ (54)	$ (79)