Financial Instruments - Schedule of Carrying Amounts and Estimated Fair Values (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 6,021	$ 6,049
Carrying Amount | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt and current portion of long-term debt	23	24
Long-term debt	6,021	6,049
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	15	1
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	4,773	4,791
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	13,603	14,396
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	23	24
Long-term debt	6,011	6,214
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	15	1
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	4,808	4,822
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	$ 13,739	$ 14,634