Transfers of Receivables - Assets and Liabilities of Securitizations (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Securitization Transactions [Line Items]
Cash and cash equivalents	$ 7,613,000,000	$ 9,189,000,000	$ 7,747,000,000	$ 8,713,000,000
Financing and Loans and Leases Receivable Allowance	389,000,000	408,000,000	479,000,000	534,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	92,530,000,000		84,528,000,000
Related Debt	90,118,000,000	89,258,000,000
Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,977,000,000	2,877,000,000
Related Debt	40,527,000,000	40,245,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	3,100,000,000	3,000,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	57,200,000,000	57,200,000,000
Financing and Loans and Leases Receivable Allowance	200,000,000	200,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	57,000,000,000	57,000,000,000
Related Debt	43,200,000,000	43,400,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,700,000,000	2,600,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	50,600,000,000	50,900,000,000
Financing and Loans and Leases Receivable Allowance	200,000,000	200,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	50,400,000,000	50,700,000,000
Related Debt	38,500,000,000	39,200,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,400,000,000	2,300,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	28,300,000,000	29,300,000,000
Financing and Loans and Leases Receivable Allowance	200,000,000	200,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	28,100,000,000	29,100,000,000
Related Debt	24,700,000,000	25,400,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300,000,000	300,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	22,300,000,000	21,600,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	22,300,000,000	21,600,000,000
Related Debt	13,800,000,000	13,800,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	400,000,000	400,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	6,600,000,000	6,300,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	6,600,000,000	6,300,000,000
Related Debt	4,700,000,000	4,200,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	3,000,000,000	2,900,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	54,200,000,000	53,700,000,000
Financing and Loans and Leases Receivable Allowance	200,000,000	200,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	54,000,000,000	53,500,000,000
Related Debt	40,500,000,000	40,200,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,600,000,000	2,500,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	47,600,000,000	47,400,000,000
Financing and Loans and Leases Receivable Allowance	200,000,000	200,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	47,400,000,000	47,200,000,000
Related Debt	35,800,000,000	36,000,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,300,000,000	2,200,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	26,500,000,000	26,900,000,000
Financing and Loans and Leases Receivable Allowance	200,000,000	200,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	26,300,000,000	26,700,000,000
Related Debt	23,000,000,000	23,200,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300,000,000	300,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	21,100,000,000	20,500,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	21,100,000,000	20,500,000,000
Related Debt	12,800,000,000	12,800,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	400,000,000	400,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	6,600,000,000	6,300,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	6,600,000,000	6,300,000,000
Related Debt	4,700,000,000	4,200,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	100,000,000	100,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	3,000,000,000	3,500,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	3,000,000,000	3,500,000,000
Related Debt	2,700,000,000	3,200,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	100,000,000	100,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	3,000,000,000	3,500,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	3,000,000,000	3,500,000,000
Related Debt	2,700,000,000	3,200,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	100,000,000	100,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	1,800,000,000	2,400,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	1,800,000,000	2,400,000,000
Related Debt	1,700,000,000	2,200,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	0	0
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	1,200,000,000	1,100,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	1,200,000,000	1,100,000,000
Related Debt	1,000,000,000	1,000,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	0	0
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	0	0
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	0	0
Related Debt	$ 0	$ 0