Finance Receivables and Allowance for Credit Losses Allowance for credit losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 873	$ 763	$ 873	$ 763	$ 870	$ 845	$ 845	$ 925
Finance receivables, net	105,434		105,434			100,513
Financing Receivable, Allowance for Credit Loss, Writeoff	(78)	(62)	(174)	(124)
Financing Receivable, Allowance for Credit Loss, Recovery	38	45	77	89
Financing Receivable, Credit Loss, Expense (Reversal)	40	(56)	117	(120)
Financing Receivable, Allowance for Credit Losses, Other	3	(9)	8	(7)
Financing Receivable, before Allowance for Credit Loss	106,307		106,307			101,358
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	$ 3		$ 28
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	$ 7	9	$ 7	9	7	7	19	22
Financing Receivable, Allowance for Credit Loss, Writeoff	0	(1)	0	(1)
Financing Receivable, Allowance for Credit Loss, Recovery	0	1	1	2
Financing Receivable, Credit Loss, Expense (Reversal)	0	(8)	(1)	(13)
Financing Receivable, Allowance for Credit Losses, Other	0	(2)	0	(1)
Financing Receivable, before Allowance for Credit Loss	31,749		31,749			29,855
Consumer Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	866	754	866	754	$ 863	838	$ 826	$ 903
Financing Receivable, Allowance for Credit Loss, Writeoff	(78)	(61)	(174)	(123)
Financing Receivable, Allowance for Credit Loss, Recovery	38	44	76	87
Financing Receivable, Credit Loss, Expense (Reversal)	40	(48)	118	(107)
Financing Receivable, Allowance for Credit Losses, Other	3	$ (7)	8	$ (6)
Financing Receivable, before Allowance for Credit Loss	74,558		74,558			71,503
Retail Installment loans, dealer financing, and other financing [Member]
Allowance for Credit Losses [Line Items]
Finance receivables, net	$ 98,566		$ 98,566			$ 94,090