Segment Reporting - Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Finance receivables, net	$ 55,153	$ 53,473
Total assets	109,211	109,217
North America Segment [Member]
Segment Reporting Information [Line Items]
Finance receivables, net	50,623	46,679
Total assets	101,762	99,453
International Segment [Member]
Segment Reporting Information [Line Items]
Finance receivables, net	4,530	6,794
Total assets	7,449	9,764
Assets Leased to Others [Member]
Segment Reporting Information [Line Items]
Leased vehicles, net (Note 4; Note 8 VIEs)	39,358	42,055
Assets Leased to Others [Member] | North America Segment [Member]
Segment Reporting Information [Line Items]
Leased vehicles, net (Note 4; Note 8 VIEs)	39,213	41,881
Assets Leased to Others [Member] | International Segment [Member]
Segment Reporting Information [Line Items]
Leased vehicles, net (Note 4; Note 8 VIEs)	$ 145	$ 174