Leased Vehicles - Leased Vehicles (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property Subject to or Available for Operating Lease, Net [Abstract]
Leased vehicles	$ 62,203	$ 48,340
Manufacturer subvention	(9,468)	(7,686)
Leased Vehicles Accounted For Operating Leases Net Of Manufacturing Incentives	52,735	40,654	$ 22,913	$ 8,238
Less: accumulated depreciation	(9,853)	(6,312)
Leased vehicles, net	$ 42,882	$ 34,342	$ 20,100