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, 2024	Mar. 31, 2023
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ 212	$ 183
Foreign exchange contracts | Foreign exchange trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	207	232
Foreign exchange contracts | Interest expense
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	49	5
Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	7	1
Other derivative contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income		$ (55)
Other derivative contracts | Other fee revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(2)
Other derivative contracts | Compensation and employee benefits
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ (49)