Segment Information - Summary of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Segment Reporting Information [Line Items]
Revenue	$ 415		$ 354		$ 1,183		$ 958
Adjusted EBITDA	130	[1]	119	[2]	379	[1]	370	[2]
Depreciation	(13)		(12)		(42)		(33)
Amortization of intangible assets	(10)		(6)		(26)		(11)
Stock-based compensation	(19)		(17)		(52)		(46)
Other non-recurring expenses					(2)
Operating income	88		84		257		280
Other income (expense), net	10		(9)		8		(13)
Income before income taxes	98		75		265		267
Provision for income taxes	(24)		(21)		(70)		(77)
Net income	74		54		195		190
Operating Segments | Hotel
Segment Reporting Information [Line Items]
Revenue	340		315		1,003		884
Adjusted EBITDA	121	[1]	118	[2]	377	[1]	372	[2]
Operating income	121		118		377		372
Operating Segments | Other Segment
Segment Reporting Information [Line Items]
Revenue	75		39		180		74
Adjusted EBITDA	9	[1]	1	[2]	2	[1]	(2)	[2]
Operating income	9		1		2		(2)
Corporate and Unallocated
Segment Reporting Information [Line Items]
Depreciation	(13)		(12)		(42)		(33)
Amortization of intangible assets	(10)		(6)		(26)		(11)
Stock-based compensation	(19)		(17)		(52)		(46)
Other non-recurring expenses					(2)
Operating income	$ (42)		$ (35)		$ (122)		$ (90)

[1] Includes allocated general and administrative expenses in our Hotel segment of $23 million and $69 million; and in our Other segment of $8 million and $23 million for the three and nine months ended September 30, 2015, respectively.

[2] Includes allocated general and administrative expenses in our Hotel segment of $24 million and $65 million; and in our Other segment of $6 million and $12 million for the three and nine months ended September 30, 2014, respectively.