Receivables - Additional Information Relating to Trouble Debt Restructuring Loan (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Average balance of TDR Loans:
Total average balance of TDR Loans	$ 15,943	$ 16,376	$ 15,930	$ 16,285
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	271	299	581	538
Real estate secured [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	15,943	15,176	15,930	15,007
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	271	253	541	450
First Lien [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	14,784	14,021	14,755	13,864
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	243	226	485	402
Second Lien [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	1,159	1,155	1,175	1,143
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	28	27	56	48
Personal non-credit card [Member]
Average balance of TDR Loans:
Total average balance of TDR Loans	0	1,200	0	1,278
Interest income recognized on TDR Loans:
Total interest income recognized on TDR Loans	$ 0	$ 46	$ 40	$ 88