Commitments and Contingencies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) classAction	Mar. 31, 2023	Sep. 30, 2022 USD ($)
Schedule Of Commitments And Contingencies [Line Items]
Number of class actions | classAction	2
Number of class actions seeking damages | classAction	1
Range of possible loss (up to)	$ 35
Purchase obligation over the next twelve months	$ 6,300
Long-term purchase commitment, term	12 months
Purchase commitment period decrease	$ (400)
Other receivables	252		$ 225
Realogy
Schedule Of Commitments And Contingencies [Line Items]
Other receivables	37
Wyndham
Schedule Of Commitments And Contingencies [Line Items]
Other receivables	$ 22
Tax Liability | Real Estate Inc
Schedule Of Commitments And Contingencies [Line Items]
Liability assumed, percent		62.50%
Tax Liability | Wyndham Hotels And Resorts Inc And Travel + Leisure Co.
Schedule Of Commitments And Contingencies [Line Items]
Liability assumed, percent		37.50%