Leases - Lessor (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total lease revenues	$ 11,543	$ 11,821	$ 11,829
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenues	Revenues	Revenues
Avis
Disaggregation of Revenue [Line Items]
Total lease revenues	$ 6,609	$ 6,660	$ 6,420
Budget
Disaggregation of Revenue [Line Items]
Total lease revenues	4,220	4,425	4,650
Other
Disaggregation of Revenue [Line Items]
Total lease revenues	714	736	759
Americas
Disaggregation of Revenue [Line Items]
Total lease revenues	8,970	9,261	9,401
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total lease revenues	1,958	1,932	1,852
Asia and Australasia
Disaggregation of Revenue [Line Items]
Total lease revenues	$ 615	$ 628	$ 576