Transfers of Receivables - Assets and Liabilities of Securitizations (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Securitization Transactions [Line Items]
Cash and cash equivalents	$ 7,294,000,000	$ 6,179,000,000	$ 8,441,000,000	$ 9,424,000,000
Financing and Loans and Leases Receivable Allowance	355,000,000	359,000,000	358,000,000	380,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	108,482,000,000		102,878,000,000
Related Debt	109,076,000,000	105,037,000,000
Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,332,000,000	2,094,000,000
Related Debt	39,409,000,000	37,156,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,600,000,000	2,400,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	57,300,000,000	55,800,000,000
Financing and Loans and Leases Receivable Allowance	100,000,000	100,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	57,200,000,000	55,700,000,000
Related Debt	45,100,000,000	43,300,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,000,000,000	2,000,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	47,200,000,000	46,200,000,000
Financing and Loans and Leases Receivable Allowance	100,000,000	100,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	47,100,000,000	46,100,000,000
Related Debt	38,300,000,000	36,700,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	1,800,000,000	1,700,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	25,900,000,000	24,400,000,000
Financing and Loans and Leases Receivable Allowance	100,000,000	100,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	25,800,000,000	24,300,000,000
Related Debt	24,000,000,000	22,500,000,000
Securitization Transactions [Member] | Consolidated Entity Including Variable Interest Entities (VIE) [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	200,000,000	300,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	21,300,000,000	21,800,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	21,300,000,000	21,800,000,000
Related Debt	14,300,000,000	14,200,000,000
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	600,000,000	400,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	10,100,000,000	9,600,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	10,100,000,000	9,600,000,000
Related Debt	6,800,000,000	6,600,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,300,000,000	2,100,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	51,200,000,000	49,200,000,000
Financing and Loans and Leases Receivable Allowance	100,000,000	100,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	51,100,000,000	49,100,000,000
Related Debt	39,400,000,000	37,200,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	1,700,000,000	1,700,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	41,100,000,000	39,600,000,000
Financing and Loans and Leases Receivable Allowance	100,000,000	100,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	41,000,000,000	39,500,000,000
Related Debt	32,600,000,000	30,600,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	1,500,000,000	1,400,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	20,700,000,000	18,800,000,000
Financing and Loans and Leases Receivable Allowance	100,000,000	100,000,000
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	20,600,000,000	18,700,000,000
Related Debt	19,200,000,000	17,300,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	200,000,000	300,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	20,400,000,000	20,800,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	20,400,000,000	20,800,000,000
Related Debt	13,400,000,000	13,300,000,000
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	600,000,000	400,000,000
Finance Receivables & Net Investment in Operating Leases, Before Allowance for Credit Losses	10,100,000,000	9,600,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	10,100,000,000	9,600,000,000
Related Debt	6,800,000,000	6,600,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [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	6,100,000,000	6,600,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	6,100,000,000	6,600,000,000
Related Debt	5,700,000,000	6,100,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Financing Receivable [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	6,100,000,000	6,600,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	6,100,000,000	6,600,000,000
Related Debt	5,700,000,000	6,100,000,000
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Retail [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	5,200,000,000	5,600,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	5,200,000,000	5,600,000,000
Related Debt	4,800,000,000	5,200,000,000
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	900,000,000	1,000,000,000
Financing and Loans and Leases Receivable Allowance	0	0
Finance Receivables & Net Investment In Operating Leases, After Allowance for Credit Losses	900,000,000	1,000,000,000
Related Debt	900,000,000	900,000,000
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