Basis of Presentation (Disaggregated Revenue in Basis of Presentation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 3,048	$ 3,123	$ 5,599	$ 5,680
Avis
Disaggregation of Revenue [Line Items]
Revenues	1,747	1,748	3,207	3,163
Budget
Disaggregation of Revenue [Line Items]
Revenues	1,117	1,180	2,038	2,157
Other
Disaggregation of Revenue [Line Items]
Revenues	184	195	354	360
Americas
Disaggregation of Revenue [Line Items]
Revenues	2,361	2,428	4,354	4,444
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	544	543	926	910
Asia and Australasia
Disaggregation of Revenue [Line Items]
Revenues	$ 143	$ 152	$ 319	$ 326