Summary of Results of Operations for One Hotel Sold in Twenty Fifteen and Five Hotels Sold in Twenty Fourteen which are Included in Continuing Operations (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Disposal Group Not Discontinued Operation Disposal Disclosures [Abstract]
Revenues	$ 16	$ 45	$ 32	$ 89
Income before taxes	2	$ 7		10
Gain on disposals	$ 53		$ 56	$ 111