Goodwill and Other Intangible Assets - Amortization Expense (Details 7) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	$ 152	$ 191	$ 304	$ 384
Purchased Credit Card Relationships [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	52	67	105	136
Other credit card- related intangibles [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	15	27	29	54
Core Deposit Intangibles [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	50	61	100	122
Other intangibles [Member]
Amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
Amortization expense	$ 35	$ 36	$ 70	$ 72