Leased Vehicles - Leased Vehicles Summary (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Leased Vehicles Accounted For Operating Leases, Net [Roll Forward]
Balance at beginning of period	$ 23,005	$ 8,268	$ 4,025
Leased vehicles purchased	25,377	20,199	6,169
Terminated leases	(4,095)	(1,785)	(878)
Leased vehicles returned - default	(358)	(120)	(58)
Manufacturer subvention	(3,111)	(3,169)	(844)
Foreign currency translation	57	(388)	(146)
Balance at end of period	$ 40,875	$ 23,005	$ 8,268