Transfers of Receivables - Assets and Liabilities of Securitizations (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Securitization Transactions [Line Items]
Cash and cash equivalents	$ 9,607	$ 9,558
Allowance for Credit Losses	667	668	$ 548
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	146,263	142,664	$ 130,190
Related Debt	$ 140,146	137,828
Finance Receivables Classification [Abstract]
Threshold of whether it is probable that finance receivables will be held for the foreseeable future	70.00%
Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	$ 2,728	3,479
Related Debt	53,269	46,437
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,700	3,500
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	75,200	68,000
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	75,000	67,800
Related Debt	53,300	46,400
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,200	3,000
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	58,900	56,500
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	58,700	56,300
Related Debt	43,100	39,200
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	1,900	1,800
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	34,000	32,600
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	33,800	32,400
Related Debt	29,200	27,700
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	1,200
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	24,900	23,900
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	24,900	23,900
Related Debt	13,900	11,500
Variable Interest Entity, Primary Beneficiary [Member] | Securitization Transactions [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	500	500
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	16,300	11,500
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	16,300	11,500
Related Debt	10,200	7,200
Consolidated Entities [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	3,000	3,800
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	82,700	74,900
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	82,500	74,700
Related Debt	59,800	52,600
Consolidated Entities [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,500	3,300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	66,400	63,400
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	66,200	63,200
Related Debt	49,600	45,400
Consolidated Entities [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	2,200	2,100
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	40,700	38,900
Allowance for Credit Losses	200	200
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	40,500	38,700
Related Debt	35,100	33,400
Consolidated Entities [Member] | Securitization Transactions [Member] | Wholesale [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	1,200
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	25,700	24,500
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	25,700	24,500
Related Debt	14,500	12,000
Consolidated Entities [Member] | Securitization Transactions [Member] | Net Investment in Operating Leases [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	500	500
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	16,300	11,500
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	16,300	11,500
Related Debt	10,200	7,200
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	7,500	6,900
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	7,500	6,900
Related Debt	6,500	6,200
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Financing Receivable [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	7,500	6,900
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	7,500	6,900
Related Debt	6,500	6,200
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | Securitization Transactions [Member] | Retail [Member]
Securitization Transactions [Line Items]
Cash and cash equivalents	300	300
Finance Receivables and Net Investment in Operating Leases, Before Allowance for Credit Losses	6,700	6,300
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	6,700	6,300
Related Debt	5,900	5,700
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	800	600
Allowance for Credit Losses	0	0
Finance Receivables and Net Investment In Operating Leases, After Allowance for Credit Losses	800	600
Related Debt	600	500
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