Goodwill and Other Intangible Assets - Goodwill Attributable to Each Business Segments (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 13,978
Acquisitions	0
Other adjustments	(8)
Goodwill, Ending Balance	13,970
Credit Card
Goodwill [Roll Forward]
Goodwill, Beginning Balance	5,005
Acquisitions	0
Other adjustments	(2)
Goodwill, Ending Balance	5,003
Consumer Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance	4,585
Acquisitions	0
Other adjustments	(1)
Goodwill, Ending Balance	4,584
Commercial Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance	4,388
Acquisitions	0
Other adjustments	(5)
Goodwill, Ending Balance	$ 4,383