Discontinued Operations - Results of Discontinued Operations (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Income from discontinued operations before income tax	$ 315		$ 871		$ 878
Bank Note [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net interest income and other revenues	0		19		102
Income from discontinued operations before income tax	0		0		23
Credit Card Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net interest income and other revenues	541	[1],[2]	1,936	[1],[2]	2,673	[1],[2]
Income from discontinued operations before income tax	$ 315		$ 871		$ 855

[1] Interest expense was allocated to discontinued operations in accordance with our existing internal transfer pricing policy. This policy uses match funding based on the expected lives of the assets and liabilities of the business at the time of origination, subject to periodic review, as demonstrated by the expected cash flows and re-pricing characteristics of the underlying assets.

[2] Included in other revenues in the year ended December 31, 2012 and 2011 was $440 million and $604 million, respectively, of lower of amortized cost or fair value adjustments.