Commitments And Contingencies (Narrative) (Detail) $ in Millions	1 Months Ended		3 Months Ended
	Nov. 30, 2017 lawsuit	Nov. 30, 2011 class	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)
Schedule Of Commitments And Contingencies [Line Items]
Range of possible loss (up to)			$ 35
Purchase obligation over the next twelve months			9,300
Purchase commitment period increase			2,600
Other receivables			$ 137	$ 64
Long-term purchase commitment, term			12 months
Electronic Toll Service Dispute | Jose Mendez v Avis Budget Group Inc
Schedule Of Commitments And Contingencies [Line Items]
Number of cases brought by plaintiffs | class		2
Breach of Contract | Jose Mendez v Avis Budget Group Inc
Schedule Of Commitments And Contingencies [Line Items]
Number of claims filed | lawsuit	2
Fines And Fees Charged To Renters | Jose Mendez v Avis Budget Group Inc
Schedule Of Commitments And Contingencies [Line Items]
Number of claims filed | lawsuit	1
Realogy
Schedule Of Commitments And Contingencies [Line Items]
Other receivables			$ 36
Wyndham
Schedule Of Commitments And Contingencies [Line Items]
Other receivables			$ 21
Real Estate Inc | Tax Liability
Schedule Of Commitments And Contingencies [Line Items]
Liability assumed, percent			62.50%
Wyndham Hotels And Resorts Inc And Travel + Leisure Co. | Tax Liability
Schedule Of Commitments And Contingencies [Line Items]
Liability assumed, percent			37.50%