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, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ 145	$ 217	$ 330	$ 421
Foreign exchange contracts | Foreign exchange trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	191	230	423	469
Foreign exchange contracts | Interest expense
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(22)	3	(16)	16
Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	0	(6)	1	0
Other derivative contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ (24)	$ (10)	$ (78)	$ (64)