Components of Company's Vehicles (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure Components Of Companys Vehicles [Abstract]
Rental vehicles	$ 13,461	$ 12,548
Less: Accumulated depreciation	(1,621)	(1,670)
Rental Vehicles Net, Total	11,840	10,878
Vehicles held for sale	337	596
Vehicles, net	$ 12,177	$ 11,474