Vehicle Rental Activities - Components of Company's Vehicles (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Disclosure Components Of Companys Vehicles [Abstract]
Rental vehicles	$ 14,612	$ 9,210
Less: Accumulated depreciation	(1,911)	(1,337)
Rental Vehicles Net, Total	12,701	7,873
Vehicles held for sale	165	280
Vehicles, net	$ 12,866	$ 8,153