Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenue		$ 1,480	$ 1,492	$ 1,246
Costs and expenses:
Cost of revenue	[1]	71	58	40
Selling and marketing	[2]	756	692	502
Technology and content	[2]	243	207	171
General and administrative (Note 17)	[2]	143	210	128
Depreciation		69	57	47
Amortization of intangible assets		32	36	18
Total costs and expenses		1,314	1,260	906
Operating income		166	232	340
Other income (expense):
Interest expense		(12)	(10)	(9)
Interest income and other, net (Note 18)		(3)	17	(9)
Total other income (expense), net		(15)	7	(18)
Income before income taxes		151	239	322
Provision for income taxes		(31)	(41)	(96)
Net income		$ 120	$ 198	$ 226
Earnings per share attributable to common stockholders (Note 5):
Basic		$ 0.83	$ 1.38	$ 1.58
Diluted		$ 0.82	$ 1.36	$ 1.55
Weighted average common shares outstanding (Note 5):
Basic		145,443	143,836	142,721
Diluted		146,893	145,967	145,800

[1] Excludes amortization expense as follows:

[2] Includes stock-based compensation expense as follows: