Fair Value Measurements - Assets and Liabilities Recorded at Fair Value on Non-recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended				9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Real Estate Secured [Member]	Sep. 30, 2012 Real Estate Secured [Member]	Sep. 30, 2013 Real Estate Secured [Member]	Sep. 30, 2012 Real Estate Secured [Member]	Sep. 30, 2013 Personal non-credit card [Member]	Sep. 30, 2012 Personal non-credit card [Member]	Sep. 30, 2013 Personal non-credit card [Member]	Sep. 30, 2012 Personal non-credit card [Member]	Sep. 30, 2013 Receivables Held For Sale [Member]	Sep. 30, 2012 Receivables Held For Sale [Member]	Sep. 30, 2013 Receivables Held For Sale [Member]	Sep. 30, 2012 Receivables Held For Sale [Member]	Sep. 30, 2013 Real Estate Owned [Member]		Sep. 30, 2012 Real Estate Owned [Member]		Sep. 30, 2013 Real Estate Owned [Member]		Sep. 30, 2012 Real Estate Owned [Member]		Sep. 30, 2013 Level 1 [Member]	Dec. 31, 2012 Level 1 [Member]	Sep. 30, 2013 Level 2 [Member]	Dec. 31, 2012 Level 2 [Member]	Sep. 30, 2013 Level 3 [Member]	Dec. 31, 2012 Level 3 [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 1 [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 1 [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Real Estate Secured [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Real Estate Secured [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Personal non-credit card [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Personal non-credit card [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Receivables Held For Sale [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Receivables Held For Sale [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Real Estate Owned [Member]		Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 1 [Member] Real Estate Owned [Member]		Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 2 [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 2 [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Real Estate Secured [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Real Estate Secured [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Personal non-credit card [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Personal non-credit card [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Receivables Held For Sale [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Receivables Held For Sale [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Real Estate Owned [Member]		Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 2 [Member] Real Estate Owned [Member]		Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 3 [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 3 [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Real Estate Secured [Member]	Dec. 31, 2012 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Real Estate Secured [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Real Estate Secured [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Personal non-credit card [Member]	Dec. 31, 2012 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Personal non-credit card [Member]		Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Personal non-credit card [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Receivables Held For Sale [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Receivables Held For Sale [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Real Estate Owned [Member]		Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Level 3 [Member] Real Estate Owned [Member]		Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Total [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Total [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Total [Member] Real Estate Secured [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Total [Member] Real Estate Secured [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Total [Member] Personal non-credit card [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Total [Member] Personal non-credit card [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Total [Member] Receivables Held For Sale [Member]	Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Total [Member] Receivables Held For Sale [Member]	Sep. 30, 2013 Non-Recurring Fair Value Measurements [Member] Total [Member] Real Estate Owned [Member]		Sep. 30, 2012 Non-Recurring Fair Value Measurements [Member] Total [Member] Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total receivables held for sale																									$ 0	$ 0	$ 901	$ 0	$ 3,816	$ 6,203			$ 0	$ 0	$ 0	$ 0	$ 0	$ 0							$ 901	$ 0	$ 0	$ 0	$ 901	$ 0							$ 3,816	$ 3,022	$ 3,181	$ 0	$ 3,181	[1]	$ 3,180	$ 3,816	$ 6,361							$ 4,717	$ 3,181	$ 0	$ 3,180	$ 4,717	$ 6,361
Real estate owned																																							0	[2]	0	[2]									392	[2]	231	[2]												0	[2]	0	[2]									392	[2]	231	[2]
Total assets at fair value on a non-recurring basis																															0	0											1,293	231											3,816	6,361														5,109	6,592
Total Gains (Losses)	$ 46	$ (73)	$ 837	$ (1,785)	$ 66	$ 45	$ 974	$ (1,304)	$ 0	$ (95)	$ (82)	$ (405)	$ 66	$ (50)	$ 892	$ (1,709)	$ (20)	[2]	$ (23)	[2]	$ (55)	[2]	$ (76)	[2]

[1] Our personal non-credit card portfolio held for sale was classified as Level 3 at December 31, 2012. This portfolio of receivables was sold on April 1, 2013 as previously discussed.

[2] Real estate owned is required to be reported on the balance sheet net of transactions costs. The real estate owned amounts in the table above reflect the fair value of the underlying asset unadjusted for transaction costs.