Leases (Lessor) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Lessor, Lease, Description [Line Items]
Total lease revenues	$ 3,496	$ 2,967	$ 9,096	$ 6,651
Avis
Lessor, Lease, Description [Line Items]
Total lease revenues	1,926	1,573	4,915	3,464
Budget
Lessor, Lease, Description [Line Items]
Total lease revenues	1,356	1,185	3,598	2,676
Other
Lessor, Lease, Description [Line Items]
Total lease revenues	214	209	583	511
Americas
Lessor, Lease, Description [Line Items]
Total lease revenues	2,682	2,391	7,216	5,417
Europe, Middle East and Africa
Lessor, Lease, Description [Line Items]
Total lease revenues	654	508	1,468	968
Asia and Australasia
Lessor, Lease, Description [Line Items]
Total lease revenues	$ 160	$ 68	$ 412	$ 266