Financial Instruments (Schedule Of Carrying Amounts And Estimated Fair Values) (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt and current portion of long-term debt	$ 18	$ 19
Long-term debt	4,009	4,191
Carrying Amount \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt and current portion of long-term debt	18	19
Long-term debt	4,009	4,191
Carrying Amount \| Interest rate caps \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps and interest rate caps	3	2
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	2,629	1,775
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	8,117	5,080
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	18	18
Long-term debt	4,170	4,337
Estimated Fair Value \| Interest rate caps \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps and interest rate caps	3	2
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	2,650	1,796
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	$ 8,350	$ 5,317

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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