Receivables - TDR Loans (Parenthetical) (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Total TDR Loans	$ 20,935,000,000	$ 17,279,000,000
Delinquent receivables HFS lower of amortized cost	1,500,000,000	2,500,000,000
First Mortgage [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	18,451,000,000	14,813,000,000
Second Mortgage [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	1,345,000,000	1,125,000,000
Real estate secured [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	19,796,000,000	15,938,000,000
Personal non-credit card [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	1,139,000,000	1,341,000,000
Receivables Held For Sale [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	$ 2,500,000,000	$ 0