Vehicle Rental Activities (Components Of The Company's Vehicles) (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Vehicle Rental Activities [Abstract]
Rental vehicles	$ 13,616	$ 11,652
Less: Accumulated depreciation	(1,608)	(1,652)
Rental Vehicles Net, Total	12,008	10,000
Vehicles held for sale	346	626
Vehicles, net	12,354	$ 10,626
Accounts Payable, Other, Current	641		$ 546
Other Receivables	$ 329		$ 277