Receivables - Additional Information Relating to Trouble Debt Restructuring Loan (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Average balance of TDR Loans:
Total average balance of TDR Loans	$ 15,763	$ 15,208	$ 15,875	$ 15,925
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	261	298	842	836
Real estate secured [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	15,763	14,638	15,875	14,884
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	261	254	802	704
First Lien [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	14,634	13,486	14,715	13,738
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	234	227	719	629
Second Lien [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	1,129	1,152	1,160	1,146
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	27	27	83	75
Personal non-credit card [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	0	570	0	1,041
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	$ 0	$ 44	$ 40	$ 132