Vehicle Rental Activities (Components of the Company's Vehicles) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Rental vehicles	$ 24,110	$ 23,114
Less: Accumulated depreciation	(2,647)	(2,639)
Rental Vehicles Net, Total	21,463	20,475
Vehicles held for sale	521	734
Vehicle, net investment in lease	36	31
Vehicles, net	22,020	$ 21,240
Liabilities under vehicle programs	483		$ 314
Other receivables	$ 239		$ 137