Goodwill and Intangible Assets - Goodwill Business Segments (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 14,777
Acquisitions	273
Other adjustments	(2)
Goodwill, Ending Balance	15,048
Credit Card
Goodwill [Roll Forward]
Goodwill, Beginning Balance	5,078
Acquisitions	273
Other adjustments	(2)
Goodwill, Ending Balance	5,349
Consumer Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance	4,645
Acquisitions	0
Other adjustments	0
Goodwill, Ending Balance	4,645
Commercial Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance	5,054
Acquisitions	0
Other adjustments	0
Goodwill, Ending Balance	$ 5,054