Derivative Financial Instruments - Impact of Derivatives on Consolidated Statement of Income (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ 217	$ 160	$ 421	$ 346
Foreign exchange contracts | Foreign exchange trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	230	188	469	431
Foreign exchange contracts | Interest expense
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	3	16	16	37
Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(6)	1	0	1
Other derivative contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ (10)	$ (45)	$ (64)	$ (123)