Segment Reporting - Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Total revenue	$ 3,156	$ 3,407
Operating expenses	372	411
Leased vehicle expenses	855	1,244
Provision for loan losses	122	(26)
Interest expense	577	650
Equity income	54	54
Income before income taxes	1,284	1,182
North America Segment
Segment Reporting Information [Line Items]
Total revenue	2,930	3,171
Operating expenses	303	339
Leased vehicle expenses	842	1,231
Provision for loan losses	98	(44)
Interest expense	507	592
Equity income	0	0
Income before income taxes	1,179	1,053
International Segment
Segment Reporting Information [Line Items]
Total revenue	226	236
Operating expenses	69	72
Leased vehicle expenses	13	13
Provision for loan losses	24	18
Interest expense	70	58
Equity income	54	54
Income before income taxes	$ 105	$ 129