Line of Business Information - Components of Other (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Fee revenue		$ 9,480	$ 9,606	$ 10,012
Net repositioning charges		(203)	(78)
Net acquisition and restructuring costs		15	(65)	(65)
Deferred incentive compensation expense acceleration		(147)
Income before income tax expense		2,316	3,327	3,171
Other
Segment Reporting Information [Line Items]
Fee revenue		0	23	0
Other Income		(294)	0	111
FDIC special assessment	$ (387)	(387)	0	0
Net repositioning charges		(203)	(70)	3
Net acquisition and restructuring costs		15	(65)	(65)
Legal and related expenses		0	0	(18)
Deferred incentive compensation expense acceleration		0	0	(147)
Other expenses		(55)	(10)	(35)
Income before income tax expense		$ (924)	$ (122)	$ (151)