Finance Receivables - Aging Analysis (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 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	$ 76,999	$ 75,448	$ 73,029
International Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivables	16,996	16,642
North America Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivables	60,003	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	11	13
Finance Receivables Aging Analysis [Abstract]
31-60 Days past due	494	829
61-90 Days past due	65	114
91-120 Days past due	24	30
Greater than 120 days past due	71	81
Total past due	654	1,054
Current	46,099	45,928
Financing Receivables	46,753	46,982
Consumer Portfolio Segment [Member] | International Segment [Member]
Finance Receivables Aging Analysis [Abstract]
31-60 Days past due	47	46
61-90 Days past due	15	17
91-120 Days past due	8	9
Greater than 120 days past due	27	29
Total past due	97	101
Current	8,459	8,641
Financing Receivables	8,556	8,742
Consumer Portfolio Segment [Member] | North America Segment [Member]
Finance Receivables Aging Analysis [Abstract]
31-60 Days past due	447	783
61-90 Days past due	50	97
91-120 Days past due	16	21
Greater than 120 days past due	44	52
Total past due	557	953
Current	37,640	37,287
Financing Receivables	38,197	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		5
Finance Receivables Aging Analysis [Abstract]
Total past due	48	40
Current	30,198	28,426
Financing Receivables	30,246	28,466
Commercial Portfolio Segment [Member] | International Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	11	11
Current	8,429	7,889
Financing Receivables	8,440	7,900
Commercial Portfolio Segment [Member] | North America Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	37	29
Current	21,769	20,537
Financing Receivables	$ 21,806	$ 20,566