Segment Information (Summary of Net Revenues and Adjusted EBITDA by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Net Revenues	$ 396	$ 402	$ 1,067	$ 1,076
Adjusted EBITDA	208	200	527	505
Reportable Segments | Hotel Franchising
Segment Reporting Information [Line Items]
Net Revenues	396	402	1,067	1,076
Adjusted EBITDA	224	215	578	554
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Net Revenues	0	0	0	0
Adjusted EBITDA	$ (16)	$ (15)	$ (51)	$ (49)