Discontinued Operations Discontinued Operations-Summary of Assets and Liabilities of Disposal Group Held for Sale (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2012	Dec. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	$ 43		$ 200		$ 151	$ 103
Assets of discontinued operations	173		2,032
Liabilities of discontinued operations	220		1,501
Insurance business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	0		2
Interest bearing deposits with banks	0		29
Available-for-sale securities	0		1,411
Other assets	0		226
Assets of discontinued operations	0		1,668
Insurance policy and claim reserves	0		988
Other liabilities	1		224
Liabilities of discontinued operations	1		1,212
Card and Retail Services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	43		197
Other assets	47		84
Assets of discontinued operations	90		281
Other liabilities	218	[1]	283	[1]
Liabilities of discontinued operations	$ 218		$ 283

[1] At March 31, 2013 and December 31, 2012, other liabilities primarily consists of amounts due to Capital One for cash collections we have received on customer accounts while we continue to service these accounts on an interim basis. Additionally at March 31, 2013 and December 31, 2012, other liabilities also includes $159 million and $59 million, respectively, with respect to enhancement services products as discussed above.