Goodwill and Intangible Assets - Goodwill Attributable to Each Business Segments (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 14,480
Goodwill, Acquired During Period	14
Other adjustments	(2)
Goodwill, Ending Balance	14,492
Credit Card
Goodwill [Roll Forward]
Goodwill, Beginning Balance	4,997
Goodwill, Acquired During Period	0
Other adjustments	(2)
Goodwill, Ending Balance	4,995
Consumer Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance	4,600
Goodwill, Acquired During Period	0
Other adjustments	0
Goodwill, Ending Balance	4,600
Commercial Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance	4,883
Goodwill, Acquired During Period	14
Other adjustments	0
Goodwill, Ending Balance	$ 4,897