Finance Receivables and Allowance for Credit Losses Allowance for credit losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 763	$ 1,061	$ 763	$ 1,061	$ 845	$ 925	$ 1,223	$ 1,305
Finance receivables, net	92,219		92,219			92,350
Financing Receivable, Allowance for Credit Loss, Writeoff	(62)	(58)	(124)	(155)
Financing Receivable, Allowance for Credit Loss, Recovery	45	57	89	113
Financing Receivable, Credit Loss, Expense (Reversal)	(56)	(166)	(120)	(206)
Financing Receivable, Allowance for Credit Losses, Other	(9)	5	(7)	4
Financing Receivable, before Allowance for Credit Loss	92,982		92,982			93,275
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	$ 82		$ 162
Financing Receivable, Threshold Period Past Due, Writeoff	120 days		120 days
Commercial Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 9	39	$ 9	39	19	22	53	60
Financing Receivable, Allowance for Credit Loss, Writeoff	(1)	(3)	(1)	(3)
Financing Receivable, Allowance for Credit Loss, Recovery	1	2	2	5
Financing Receivable, Credit Loss, Expense (Reversal)	(8)	(12)	(13)	(22)
Financing Receivable, Allowance for Credit Losses, Other	(2)	(1)	(1)	(1)
Financing Receivable, before Allowance for Credit Loss	23,651		23,651			19,730
Consumer Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	754	1,022	754	1,022	$ 826	903	$ 1,170	$ 1,245
Financing Receivable, Allowance for Credit Loss, Writeoff	(61)	(55)	(123)	(152)
Financing Receivable, Allowance for Credit Loss, Recovery	44	55	87	108
Financing Receivable, Credit Loss, Expense (Reversal)	(48)	(154)	(107)	(184)
Financing Receivable, Allowance for Credit Losses, Other	(7)	$ 6	(6)	$ 5
Financing Receivable, before Allowance for Credit Loss	69,331		69,331			73,545
Retail Installment loans, dealer financing, and other financing [Member]
Allowance for Credit Losses [Line Items]
Finance receivables, net	$ 85,873		$ 85,873			$ 85,347