Selected Quarterly Financial Data (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Net interest income	$ 201	$ 210	$ 225	$ 232	$ 207	$ 229	$ 238	$ 394	$ 868	$ 1,068	$ 1,646
Provision for credit losses	(127)	(43)	(197)	2	(152)	(160)	267	24	(365)	(21)	2,224	[1]
Net interest income (loss) after provision for credit losses	328	253	422	230	359	389	(29)	370	1,233	1,089	(578)
Other revenues	(72)	169	47	82	(215)	114	628	354	226	881	(2,119)
Total operating expenses	176	174	121	217	253	216	195	268	688	932	1,114
Income (loss) from continuing operations before income tax	80	248	348	95	(109)	287	404	456	771	1,038	(3,811)
Income tax expense (benefit)	42	87	112	(17)	(51)	91	133	152	224	325	(1,406)
Income (loss) from continuing operations	38	161	236	112	(58)	196	271	304	547	713	(2,405)
Income (loss) from discontinued operations	(2)	(9)	(7)	(6)	(19)	(29)	(51)	(78)	(24)	(177)	1,560
Net income (loss)	$ 36	$ 152	$ 229	$ 106	$ (77)	$ 167	$ 220	$ 226	$ 523	$ 536	$ (845)

[1] Provision for credit losses during 2012 includes $112 million related to the lower of amortized cost or fair value attributable to credit for personal non-credit card receivables transferred to held for sale at June 30, 2012. See Note 7, "Receivables Held for Sale," for additional information.