Credit Loss Reserves - Analysis of Credit Loss Reserves (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, 2011
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]
Net charge-offs:
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	0		(965)		0		(965)		(965)
Other	0		0		8		0
Credit loss reserves at end of period	$ 4,098		$ 4,608		$ 4,098		$ 4,608

[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.