Transfers of Receivables - Assets and Liabilities of Securitizations (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Securitization Transactions [Line Items]
Cash and cash equivalents	$ 11,579	$ 9,607
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	140,301		$ 143,614
Related Debt	139,274	140,146
Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,660	2,728
Related Debt	50,981	53,269
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,700	2,700
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	69,400	75,200
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	69,200	75,000
Related Debt	51,000	53,300
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,100	2,200
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	56,700	58,900
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	56,500	58,700
Related Debt	43,000	43,100
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	1,800	1,900
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	33,300	34,000
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	33,100	33,800
Related Debt	28,800	29,200
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	23,400	24,900
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	23,400	24,900
Related Debt	14,200	13,900
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	600	500
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	12,700	16,300
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	12,700	16,300
Related Debt	8,000	10,200
Consolidated Entities [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,900	3,000
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	74,500	82,700
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	74,300	82,500
Related Debt	55,500	59,800
Consolidated Entities [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,300	2,500
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	61,800	66,400
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	61,600	66,200
Related Debt	47,500	49,600
Consolidated Entities [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,000	2,200
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	37,800	40,700
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	37,600	40,500
Related Debt	32,800	35,100
Consolidated Entities [Member] | Securitization Transactions [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	24,000	25,700
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	24,000	25,700
Related Debt	14,700	14,500
Consolidated Entities [Member] | Securitization Transactions [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	600	500
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	12,700	16,300
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	12,700	16,300
Related Debt	8,000	10,200
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	200	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	5,100	7,500
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	5,100	7,500
Related Debt	4,500	6,500
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	200	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	5,100	7,500
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	5,100	7,500
Related Debt	4,500	6,500
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	200	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	4,500	6,700
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	4,500	6,700
Related Debt	4,000	5,900
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	0	0
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	600	800
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	600	800
Related Debt	500	600
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	0	0
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	0	0
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	0	0
Related Debt	$ 0	$ 0