Credit Loss Reserves - Summarizes Changes in Credit Loss Reserves by Product/Class and Related Receivable Balance by Product (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012
Allowance for Loan and Lease Losses [Roll Forward]
Credit loss reserves at beginning of period	$ 4,313		$ 5,865		$ 4,607		$ 5,952
Provision for credit losses	267	[1]	738	[1],[2]	291	[1]	1,529	[1],[2]
Charge-offs	(527)	[2],[3]	(1,132)	[2],[3]	(926)	[2],[3]	(2,111)	[2],[3]
Recoveries	45		102		118		203
Total net charge-offs	(482)		(1,030)		(808)		(1,908)
Reserves on receivables transferred to held for sale			(965)				(965)
Other	0		0		8		0
Credit loss reserves at end of period	4,098		4,608		4,098		4,608
Reserve components:
Collectively evaluated for impairment	800		812		800		812
Individually evaluated for impairment	3,233	[1]	3,705	[1]	3,233	[1]	3,705	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	63		83		63		83
Receivables acquired with deteriorated credit quality	2		8		2		8
Total credit loss reserves	4,098		4,608		4,098		4,608
Receivables:
Collectively evaluated for impairment	16,466		21,404		16,466		21,404
Individually evaluated for impairment	11,765	[1]	12,071	[1]	11,765	[1]	12,071	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	871		1,441		871		1,441
Receivables acquired with deteriorated credit quality	10		40		10		40
Total receivables	29,112		34,956		29,112		34,956
First Lien [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Credit loss reserves at beginning of period	3,619		4,171		3,867		4,089
Provision for credit losses	250		508	[2]	266		1,150	[2]
Charge-offs	(437)	[3]	(830)	[3]	(738)	[3]	(1,398)	[3]
Recoveries	31		9		60		17
Total net charge-offs	(406)		(821)		(678)		(1,381)
Reserves on receivables transferred to held for sale			0				0
Other					8
Credit loss reserves at end of period	3,463		3,858		3,463		3,858
Reserve components:
Collectively evaluated for impairment	624		625		624		625
Individually evaluated for impairment	2,775	[1]	3,144	[1]	2,775	[1]	3,144	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	62		82		62		82
Receivables acquired with deteriorated credit quality	2		7		2		7
Total credit loss reserves	3,463		3,858		3,463		3,858
Receivables:
Collectively evaluated for impairment	14,300		18,614		14,300		18,614
Individually evaluated for impairment	10,667	[1]	10,918	[1]	10,667	[1]	10,918	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	823		1,373		823		1,373
Receivables acquired with deteriorated credit quality	8		35		8		35
Total receivables	25,798		30,940		25,798		30,940		29,301
Second Lien [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Credit loss reserves at beginning of period	694		779		740		823
Provision for credit losses	22		90	[2]	62		221	[2]
Charge-offs	(90)	[3]	(134)	[3]	(188)	[3]	(324)	[3]
Recoveries	9		15		21		30
Total net charge-offs	(81)		(119)		(167)		(294)
Reserves on receivables transferred to held for sale			0				0
Other					0
Credit loss reserves at end of period	635		750		635		750
Reserve components:
Collectively evaluated for impairment	176		187		176		187
Individually evaluated for impairment	458	[1]	561	[1]	458	[1]	561	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	1		1		1		1
Receivables acquired with deteriorated credit quality	0		1		0		1
Total credit loss reserves	635		750		635		750
Receivables:
Collectively evaluated for impairment	2,166		2,790		2,166		2,790
Individually evaluated for impairment	1,098	[1]	1,153	[1]	1,098	[1]	1,153	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	48		68		48		68
Receivables acquired with deteriorated credit quality	2		5		2		5
Total receivables	3,314		4,016		3,314		4,016		3,638
Personal non-credit card [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Credit loss reserves at beginning of period	0		915		0		1,040
Provision for credit losses	(5)		140	[2]	(37)		158	[2]
Charge-offs	0	[3]	(168)	[3]	0	[3]	(389)	[3]
Recoveries	5		78		37		156
Total net charge-offs	5		(90)		37		(233)
Reserves on receivables transferred to held for sale			(965)				(965)
Other					0
Credit loss reserves at end of period	0		0		0		0
Reserve components:
Collectively evaluated for impairment	0		0		0		0
Individually evaluated for impairment	0	[1]	0	[1]	0	[1]	0	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	0		0		0		0
Receivables acquired with deteriorated credit quality	0		0		0		0
Total credit loss reserves	0		0		0		0
Receivables:
Collectively evaluated for impairment	0		0		0		0
Individually evaluated for impairment	0	[1]	0	[1]	0	[1]	0	[1]
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell	0		0		0		0
Receivables acquired with deteriorated credit quality	0		0		0		0
Total receivables	$ 0		$ 0		$ 0		$ 0

[1] These amounts represent TDR Loans for which we evaluate reserves using a discounted cash flow methodology. Each loan is individually identified as a TDR Loan and then grouped together with other TDR Loans with similar characteristics. The discounted cash flow impairment analysis is then applied to these groups of TDR Loans. The receivable balance above excludes TDR Loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell which totaled $726 million and $671 million at June 30, 2013 and 2012, respectively. The reserve component above excludes credit loss reserves for TDR Loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell which totaled $51 million and $41 million at June 30, 2013 and 2012, respectively. These credit loss reserves are reflected within receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell in the table above.

[2] The three and six months ended June 30, 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 6, "Receivables Held for Sale," for additional information.

[3] For collateral dependent receivables that are transferred to held for sale, existing credit loss reserves at the time of transfer are recognized as a charge-off. We transferred to held for sale a pool of real estate secured receivables that were carried at the lower of amortized cost or fair value of the collateral less cost and recognized the existing credit loss reserves on these receivables as additional charge-off totaling $119 million during the three and six months ended June 30, 2013 and $333 million during the three and six months ended June 30, 2012. See Note 6, "Receivables Held for Sale," for additional information.