Goodwill and Other Intangible Assets - Goodwill Attributable to Each Business Segments (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 13,904
Acquisitions	3
Other adjustments	(1)
Goodwill, Ending Balance	13,906
Credit Card [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	5,003
Acquisitions	0
Other adjustments	(1)
Goodwill, Ending Balance	5,002
Consumer Banking [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	4,583
Acquisitions	3
Other adjustments	0
Goodwill, Ending Balance	4,586
Commercial Banking [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	4,318
Acquisitions	0
Other adjustments	0
Goodwill, Ending Balance	$ 4,318