Components of Company's Vehicles (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Disclosure Components Of Companys Vehicles [Abstract]
Rental vehicles	$ 10,937	$ 11,195
Less: Accumulated depreciation	(1,454)	(1,500)
Rental Vehicles Net, Total	9,483	9,695
Vehicles held for sale	981	963
Vehicles, net	$ 10,464	$ 10,658