Commitments and Contingencies - Commitments (Detail) In Millions, unless otherwise specified				3 Months Ended									3 Months Ended
	Mar. 31, 2015 Real Estate Investment Upper Limit USD ($)	Mar. 31, 2015 Development of Dual Branded Property USD ($)	Mar. 31, 2015 Development of Dual Branded Property BRL	Mar. 31, 2015 Investment in Other Joint Venture Commitment USD ($) Entity	Mar. 31, 2015 Investment in Other Joint Venture Commitment EUR (€)	Mar. 31, 2015 Information Technology Hardware, Software, Accounting, Finance, and Maintenance Services USD ($)	Mar. 31, 2015 Commitments USD ($)	Mar. 31, 2015 Lodging Property USD ($)	Mar. 31, 2015 Full Service and Limited Service Equity Investment for Non Controlling Interest in Partnership Commitment USD ($)	Mar. 31, 2015 Full Service and Limited Service Equity Investment for Non Controlling Interest in Partnership Commitment Upper Limit USD ($)	Mar. 31, 2015 Limited Service Equity Investment for Non Controlling Interest in Partnership Commitment USD ($)	Mar. 31, 2015 Limited Service Equity Investment for Non Controlling Interest in Partnership Commitment Upper Limit USD ($)	Mar. 31, 2015 Debt Securities Mandatorily Redeemable Preferred Equity Ownership Interest USD ($) hotel
Commitments and Contingencies Disclosure [Line Items]
Investment commitments		$ 16	52							$ 8		$ 22	$ 10
Investment commitments expected to be funded in 2015	11								2		3
Investment commitments not expected to be funded							29		6		13
Investment commitments expected to be funded in 2016											6
Acquisition interests in joint ventures				2	2
Contingent acquisition period				6 years	6 years
Deposits in conjunction with contingent obligation to acquire the interest in joint ventures				20	15
Deposits in conjunction with contingent obligation to acquire the interest in joint ventures, remaining amount				12	11
Purchase commitments						197
Purchase commitments expected to be funded in 2015						67
Purchase commitments expected to be funded in 2016						45
Purchase commitments expected to be funded in 2017						44
Purchase commitments expected to be funded thereafter						41
Number of hotels included in investment commitments													3
Loan commitment, amount								$ 2