Receivables - Receivables Classified as Trouble Debt Restructuring Loans (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Trouble debt restructuring modification
Total	$ 847	$ 1,396	$ 3,419	$ 6,065
First Lien [Member]
Trouble debt restructuring modification
Total	739	1,073	2,787	4,700
Second Lien [Member]
Trouble debt restructuring modification
Total	78	117	336	474
Real estate secured [Member]
Trouble debt restructuring modification
Total	817	1,190	3,123	5,174
Personal non-credit card [Member]
Trouble debt restructuring modification
Total	$ 30	$ 206	$ 296	$ 891