Goodwill and Other Intangible Assets - Amortization Expense (Details 7) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	$ 957	$ 848	$ 936
Purchased Credit Card Relationships [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	309	295	355
Other credit card- related intangibles [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	265	106	111
Core Deposits [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	239	285	328
Other intangibles [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	$ 144	$ 162	$ 142