Receivables - TDR Loans (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Total TDR Loans	$ 15,310	$ 15,584
Total credit loss reserves for TDR Loans	3,651	4,409
First Lien [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	13,597	13,186
Total credit loss reserves for TDR Loans	3,126	3,169
Second Lien [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	1,153	1,057
Total credit loss reserves for TDR Loans	525	534
Real estate secured [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	14,750	14,243
Total credit loss reserves for TDR Loans	3,651	3,703
Personal non-credit card [Member]
Financing Receivable, Modifications [Line Items]
Total TDR Loans	560	1,341
Total credit loss reserves for TDR Loans		$ 706