Derivative Instruments and Hedging Activities - Gains Losses on Freestanding Derivatives (Details) - Other non-interest income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in other non-interest income:	$ 74	$ 66
Interest rate contracts:
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in other non-interest income:	17	19
Interest rate contracts: | Customer accommodation:
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in other non-interest income:	7	8
Interest rate contracts: | Other interest rate exposures
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in other non-interest income:	68	52
Commodity contracts | Customer accommodation:
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in other non-interest income:	4	8
Foreign exchange and other contracts | Customer accommodation:
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in other non-interest income:	6	3
Other contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in other non-interest income:	$ (11)	$ (5)