Geographic and Business Segment Information - Reconciliation of Revenues from Consolidated Hotels to Condensed Consolidated Amounts and Hotel Adjusted EBITDA to Net Income (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting [Abstract]
Gain on sale of assets, net	$ 1	$ 1	$ 143