Goodwill and Other Intangible Assets - Rollforward of Goodwill by Operating Segment (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 17,156
Adjustments and other	1
Goodwill, Ending Balance	17,157
CSBB
Goodwill [Line Items]
Goodwill, Beginning Balance	13,503
Adjustments and other	0
Goodwill, Ending Balance	12,005
Goodwill Segment Realignment	(1,498)
WB
Goodwill [Line Items]
Goodwill, Beginning Balance	3,653
Adjustments and other	1
Goodwill, Ending Balance	5,152
Goodwill Segment Realignment	1,498
WB | Wealth
Goodwill [Line Items]
Goodwill Segment Realignment	$ 220