Discontinued Operations - Operating Results of Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			0 Months Ended	3 Months Ended				9 Months Ended				3 Months Ended		9 Months Ended			3 Months Ended				9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Mar. 29, 2013 Insurance business [Member]	Sep. 30, 2014 Insurance business [Member]		Sep. 30, 2013 Insurance business [Member]		Sep. 30, 2014 Insurance business [Member]		Sep. 30, 2013 Insurance business [Member]		Sep. 30, 2014 Commercial Business [Member]	Sep. 30, 2013 Commercial Business [Member]	Sep. 30, 2014 Commercial Business [Member]	Sep. 30, 2013 Commercial Business [Member]	Dec. 31, 2013 Commercial Business [Member]	Sep. 30, 2014 Card and Retail Services [Member]		Sep. 30, 2013 Card and Retail Services [Member]		Sep. 30, 2014 Card and Retail Services [Member]		Sep. 30, 2013 Card and Retail Services [Member]		Dec. 31, 2013 Card and Retail Services [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses						$ 153
Pre-tax gain						21
After-tax gain						13
Net interest income and other revenues							0	[1]	0	[1]	0	[1]	70	[1]	3	2	9	10		0		0		0		0
Income (loss) from discontinued operations before income tax	(4)	(33)	(24)	(228)			0		(3)		0		3		2	1	6	5		(6)	[2]	(31)	[2]	(30)	[2]	(236)	[2]
Incremental increase in industry review enhancement expense																								7		96
Assets of discontinued operations	69		69		165										62		62		63	7				7				102
Liabilities of discontinued operations	79		79		103										0		0		1	79				79				102
Provision for legal expenses and other																										$ 40

[1] Interest expense, which is included as a component of net interest income, was allocated to discontinued operations in accordance with our existing internal transfer pricing policy. This policy uses match funding based on the expected lives of the assets and liabilities of the business at the time of origination, subject to periodic review, as demonstrated by the expected cash flows and re-pricing characteristics of the underlying assets.

[2] For the three and nine months ended September 30, 2014 and 2013, the amounts include expenses related to activities to complete the separation of the credit card operational infrastructure between us and Capital One. We expect costs associated with the separation of the credit card operational infrastructure to continue through the remainder of 2014. Additionally, the nine months ended September 30, 2014 includes an incremental expense of $7 million and the nine months ended September 30, 2013 includes an incremental expense of $96 million recorded based on actions taken and actions planned to be taken in connection with an industry review of enhancement services products. For the nine months ended September 30, 2013 amounts also reflect a legal accrual of $40 million. See Note 15, "Litigation and Regulatory Matters," for further discussion of the legal matter.