Finance Receivables - Aging Analysis (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number Of Days After Which Finance Receivable Is Considered Past Due	any payment, including principal and interest, that has not been collected and is at least 31 days past the contractual due date
Finance Receivables Aging Analysis [Abstract]
Financing Receivables	$ 76,787	$ 75,448	$ 71,410
International Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivables	17,292	16,642
North America Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivables	59,495	58,806
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	12	13
Finance Receivables Aging Analysis [Abstract]
31-60 Days past due	617	829
61-90 Days past due	73	114
91-120 Days past due	25	30
Greater than 120 days past due	68	81
Total past due	783	1,054
Current	46,396	45,928
Financing Receivables	47,179	46,982
Consumer Portfolio Segment [Member] | International Segment [Member]
Finance Receivables Aging Analysis [Abstract]
31-60 Days past due	34	46
61-90 Days past due	16	17
91-120 Days past due	9	9
Greater than 120 days past due	27	29
Total past due	86	101
Current	8,803	8,641
Financing Receivables	8,889	8,742
Consumer Portfolio Segment [Member] | North America Segment [Member]
Finance Receivables Aging Analysis [Abstract]
31-60 Days past due	583	783
61-90 Days past due	57	97
91-120 Days past due	16	21
Greater than 120 days past due	41	52
Total past due	697	953
Current	37,593	37,287
Financing Receivables	38,290	38,240
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	2	5
Finance Receivables Aging Analysis [Abstract]
Total past due	20	40
Current	29,588	28,426
Financing Receivables	29,608	28,466
Commercial Portfolio Segment [Member] | International Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	8	11
Current	8,395	7,889
Financing Receivables	8,403	7,900
Commercial Portfolio Segment [Member] | North America Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	12	29
Current	21,193	20,537
Financing Receivables	$ 21,205	$ 20,566