Receivables - TDR Loans (Parenthetical) (Detail) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Total TDR Loans	$ 19,262,000,000	$ 17,279,000,000
Total reserve on debt restructuring receivables held for sale	3,651,000,000	4,409,000,000
Delinquent receivables HFS lower of amortized cost	1,000,000,000	2,500,000,000
First Lien [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	16,761,000,000	14,813,000,000
Total reserve on debt restructuring receivables held for sale	3,126,000,000	3,169,000,000
Second Lien [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	1,290,000,000	1,125,000,000
Total reserve on debt restructuring receivables held for sale	525,000,000	534,000,000
Real estate secured [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	18,051,000,000	15,938,000,000
Total reserve on debt restructuring receivables held for sale	3,651,000,000	3,703,000,000
Personal non-credit card [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	1,211,000,000	1,341,000,000
Total reserve on debt restructuring receivables held for sale		706,000,000
Receivables Held For Sale [Member]
Financing Receivable, Modifications [Line Items]
Total reserve on debt restructuring receivables held for sale	$ 2,300,000,000	$ 0