Receivables - Receivables Classified as Trouble Debt Restructuring Loans (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2012		Dec. 31, 2011
Trouble debt restructuring modification
Interest rate modification	$ 1,400	$ 1,814		$ 3,630
Re-age of past due account	3,200	2,044		4,198
Total		3,858	[1]	7,828	[1]
First Mortgage [Member]
Trouble debt restructuring modification
Total		3,235		6,145
Second Mortgage [Member]
Trouble debt restructuring modification
Total		329		625
Real estate secured [Member]
Trouble debt restructuring modification
Total		3,564		6,770
Personal non-credit card [Member]
Trouble debt restructuring modification
Total		$ 294		$ 1,058

[1] The following summarizes the actions taken during 2012 and 2011 which resulted in the above receivables being classified as a TDR Loan.