Combined Summarized Balance Sheet Information (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Investments In And Advances To Affiliates Schedule Of Investments [Abstract]
Property and equipment, net	$ 1,945	$ 1,634
Timeshare inventory	117	137
Other assets	566	514
Total assets	2,628	2,285
Debt	1,496	1,215
Other liabilities	330	319
Equity	802	751
Total liabilities and equity	$ 2,628	$ 2,285