Segment Reporting - Assets (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Finance receivables, net of fees	$ 81,650	$ 74,514
Leased vehicles, net (Note 4; Note 7)	31,061	32,701
Total assets	129,986	122,545
North America Segment
Segment Reporting Information [Line Items]
Finance receivables, net of fees	75,744	69,705
Leased vehicles, net (Note 4; Note 7)	30,735	32,454
Total assets	120,837	114,612
International Segment
Segment Reporting Information [Line Items]
Finance receivables, net of fees	5,906	4,809
Leased vehicles, net (Note 4; Note 7)	326	247
Total assets	$ 9,150	$ 7,934