Transfers of Receivables - Assets and Liabilities of Securitizations (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Securitization Transactions [Line Items]
Cash and cash equivalents	$ 9,628	$ 9,067
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	137,776		$ 146,856
Related Debt	136,836	140,029
Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,549	3,202
Related Debt	48,379	50,865
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,500	3,200
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	68,800	73,600
Allowance for Credit Losses	400	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	68,400	73,400
Related Debt	48,400	50,900
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	1,900	2,700
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	54,400	58,700
Allowance for Credit Losses	400	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	54,000	58,500
Related Debt	39,400	41,400
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	1,600	1,800
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	29,400	32,600
Allowance for Credit Losses	400	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	29,000	32,400
Related Debt	25,700	28,000
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	900
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	25,000	26,100
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	25,000	26,100
Related Debt	13,700	13,400
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	14,400	14,900
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	14,400	14,900
Related Debt	9,000	9,500
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	400	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	8,300	6,400
Allowance for Credit Losses	100	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	8,200	6,400
Related Debt	7,300	5,700
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	400	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	8,300	6,400
Allowance for Credit Losses	100	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	8,200	6,400
Related Debt	7,300	5,700
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	400	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	7,600	5,700
Allowance for Credit Losses	100	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	7,500	5,700
Related Debt	6,800	5,100
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	700	700
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	700	700
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
Consolidated Entities [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,900	3,500
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	77,100	80,000
Allowance for Credit Losses	500	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	76,600	79,800
Related Debt	55,700	56,600
Consolidated Entities [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,300	3,000
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	62,700	65,100
Allowance for Credit Losses	500	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	62,200	64,900
Related Debt	46,700	47,100
Consolidated Entities [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,000	2,100
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	37,000	38,300
Allowance for Credit Losses	500	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	36,500	38,100
Related Debt	32,500	33,100
Consolidated Entities [Member] | Securitization Transactions [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	900
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	25,700	26,800
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	25,700	26,800
Related Debt	14,200	14,000
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	14,400	14,900
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	14,400	14,900
Related Debt	$ 9,000	$ 9,500