Basis of Presentation (Disaggregated Revenue in Basis of Presentation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 2,551	$ 2,557
Avis
Disaggregation of Revenue [Line Items]
Revenues	1,460	1,415
Budget
Disaggregation of Revenue [Line Items]
Revenues	921	977
Other
Disaggregation of Revenue [Line Items]
Revenues	170	165
Americas
Disaggregation of Revenue [Line Items]
Revenues	1,993	2,016
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	382	367
Asia and Australasia
Disaggregation of Revenue [Line Items]
Revenues	$ 176	$ 174