Financial Instruments (Schedule of Carrying Amounts and Estimated Fair Values) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt and current portion of long-term debt	$ 30	$ 27
Long-term debt	4,736	4,644
Carrying Amount | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt and current portion of long-term debt	30	27
Long-term debt	4,736	4,644
Carrying Amount | Interest rate swaps and interest rate caps | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps and interest rate caps	131	111
Carrying Amount | Vehicle-backed debt due to Avis Budget Rental Car Funding | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vehicle-backed debt	3,407	2,423
Carrying Amount | Avis Budget Rental Car Funding | Vehicle-backed debt due to Avis Budget Rental Car Funding | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vehicle-backed debt	15,115	11,275
Estimated Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt and current portion of long-term debt	30	26
Long-term debt	4,629	4,411
Estimated Fair Value | Interest rate swaps and interest rate caps | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps and interest rate caps	131	111
Estimated Fair Value | Vehicle-backed debt due to Avis Budget Rental Car Funding | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vehicle-backed debt	3,410	2,422
Estimated Fair Value | Avis Budget Rental Car Funding | Vehicle-backed debt due to Avis Budget Rental Car Funding | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vehicle-backed debt	$ 14,656	$ 10,848