Goodwill and Other Intangible Assets - Future Amortization Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Estimated future amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
2014	$ 360		$ 360
2015	170		170
2016	132		132
2017	100		100
2018	81		81
Amortization of Intangible Assets	132	152	263	304
Purchased credit card relationships
Estimated future amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
2014	96		96
2015	12		12
2016	9		9
2017	5		5
2018	3		3
Amortization of Intangible Assets	45	52	90	105
Other credit card-related intangibles
Estimated future amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
2014	51		51
2015	39		39
2016	34		34
2017	29		29
2018	20		20
Amortization of Intangible Assets	14	15	27	29
Core deposit intangibles
Estimated future amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
2014	102		102
2015	26		26
2016	14		14
2017	7		7
2018	5		5
Amortization of Intangible Assets	42	50	85	100
Other intangibles
Estimated future amortization expense related to credit card relationships, core deposits and other intangible assets [Abstract]
2014	111		111
2015	93		93
2016	75		75
2017	59		59
2018	53		53
Amortization of Intangible Assets	$ 31	$ 35	$ 61	$ 70