Financial Instruments (Schedule of Carrying Amounts and Estimated Fair Values) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 6,020	$ 5,373
Carrying Amount | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt and current portion of long-term debt	38	20
Long-term debt	6,020	5,373
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	0	12
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	4,368	3,441
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	14,894	14,083
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	38	20
Long-term debt	6,181	5,452
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	0	12
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	4,397	3,469
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	$ 15,134	$ 14,154