Business Segment Information - Schedule of Total Assets by Consolidated Hotels, Reconciled to Total Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Segment Reporting Asset Reconciling Item [Line Items]
Total assets	$ 9,794	$ 10,587
Consolidated Hotels [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Total assets	9,775	10,568
All Other [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Total assets	$ 19	$ 19