Finance Receivables and Allowance for Credit Losses Allowance for credit losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 845	$ 1,223	$ 925	$ 1,305
Finance receivables, net	93,031		92,350
Financing Receivable, Allowance for Credit Loss, Writeoff	(62)	(97)
Financing Receivable, Allowance for Credit Loss, Recovery	44	56
Financing Receivable, Credit Loss, Expense (Reversal)	(64)	(40)
Financing Receivable, Allowance for Credit Losses, Other	2	(1)
Financing Receivable, before Allowance for Credit Loss	93,876		93,275
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	$ 80
Financing Receivable, Threshold Period Past Due, Writeoff	120 days
Commercial Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 19	53	22	60
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0
Financing Receivable, Allowance for Credit Loss, Recovery	1	3
Financing Receivable, Credit Loss, Expense (Reversal)	(5)	(10)
Financing Receivable, Allowance for Credit Losses, Other	1	0
Financing Receivable, before Allowance for Credit Loss	21,797		19,730
Consumer Portfolio Segment [Member]
Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Loss	826	1,170	903	$ 1,245
Financing Receivable, Allowance for Credit Loss, Writeoff	(62)	(97)
Financing Receivable, Allowance for Credit Loss, Recovery	43	53
Financing Receivable, Credit Loss, Expense (Reversal)	(59)	(30)
Financing Receivable, Allowance for Credit Losses, Other	1	$ (1)
Financing Receivable, before Allowance for Credit Loss	72,079		73,545
Retail Installment loans, dealer financing, and other financing [Member]
Allowance for Credit Losses [Line Items]
Finance receivables, net	$ 86,261		$ 85,347