Leased Vehicles - Leased Vehicles (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Leased Assets [Line Items]
Leased vehicles		$ 64,928
Manufacturer subvention		(9,934)
Net capitalized cost		54,994
Less: accumulated depreciation	$ (287)	(221)
Less: accumulated depreciation		(11,435)
Leased vehicles, net	42,100	43,559	$ 42,900
Leased vehicles, net	226	$ 251
Assets Leased to Others [Member]
Operating Leased Assets [Line Items]
Leased vehicles	62,767
Manufacturer subvention	(9,731)
Net capitalized cost	53,036
Less: accumulated depreciation	(10,981)
Leased vehicles, net	$ 42,055