Finance Receivables and Allowance for Credit Losses Allowance for credit losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 1,314	$ 513	$ 1,314	$ 513	$ 1,285		$ 513	$ 513	$ 589
Finance receivables, net	104,864		104,864				114,317
Financing Receivable, Allowance for Credit Loss, Writeoff	(109)	(130)	(335)	(401)
Financing Receivable, Allowance for Credit Loss, Recovery	43	41	122	137
Provision for Loan, Lease, and Other Losses	86	93	765	189
Financing Receivable, Allowance for Credit Losses, Other	9	(4)	(3)	(1)
Financing Receivable, before Allowance for Credit Loss	106,178		106,178				114,830
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	29		801
Translation [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	20		20
Commercial Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	63	15	63	15	74		17	17	23
Financing Receivable, Allowance for Credit Loss, Writeoff	(5)	(1)	(6)	(18)
Financing Receivable, Allowance for Credit Loss, Recovery	2	0	5	8
Provision for Loan, Lease, and Other Losses	(9)	0	42	2
Financing Receivable, Allowance for Credit Losses, Other	1	(1)	0	0
Financing Receivable, before Allowance for Credit Loss	28,689		28,689				40,855
Consumer Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	1,251	498	1,251	498	$ 1,211		496	$ 496	$ 566
Financing Receivable, Allowance for Credit Loss, Writeoff	(104)	(129)	(329)	(383)
Financing Receivable, Allowance for Credit Loss, Recovery	41	41	117	129
Provision for Loan, Lease, and Other Losses	95	93	723	187
Financing Receivable, Allowance for Credit Losses, Other	8	$ (3)	(3)	$ (1)
Financing Receivable, before Allowance for Credit Loss	77,489		77,489
Accounting Standards Update 2016-13 [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss						$ 252
Finance receivables, net	252		252
Accounting Standards Update 2016-13 [Member] | Commercial Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Finance receivables, net	5		5
Accounting Standards Update 2016-13 [Member] | Consumer Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Finance receivables, net	247		247
Retail Installment loans, dealer financing, and other financing [Member]
Allowance for Credit Losses [Line Items]
Finance receivables, net	$ 97,021		$ 97,021			105,901	$ 106,131
Retail Installment loans, dealer financing, and other financing [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for Credit Losses [Line Items]
Finance receivables, net						$ (230)