Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net revenue	$ 959,787	$ 779,595	$ 2,753,151	$ 2,129,017
Costs and expenses:
Cost of revenue (exclusive of depreciation and amortization shown separately below)	119,772	111,368	357,826	299,860
Sales and marketing	311,222	265,454	921,474	756,361
Product development	246,423	202,682	719,975	558,395
General and administrative	121,391	118,871	382,981	358,573
Depreciation and amortization	137,934	117,901	419,620	290,877
Total costs and expenses	936,742	816,276	2,801,876	2,264,066
Income (loss) from operations	23,045	(36,681)	(48,725)	(135,049)
Other expense, net:
Interest income	6,422	2,798	17,369	6,800
Interest expense	(13,110)	(12,773)	(38,867)	(38,064)
Other, net	(3,550)	(10,684)	(13,341)	(16,442)
Other expense, net	(10,238)	(20,659)	(34,839)	(47,706)
Income (loss) before income taxes	12,807	(57,340)	(83,564)	(182,755)
Provision (benefit) for income taxes	3,694	(10,429)	71,379	(25,905)
Net income (loss)	9,113	(46,911)	(154,943)	(156,850)
Accretion of redeemable noncontrolling interest	(554)	(512)	(1,590)	(869)
Net income (loss) attributable to common stockholders	$ 8,559	$ (47,423)	$ (156,533)	$ (157,719)
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ 0.06	$ (0.36)	$ (1.18)	$ (1.23)
Diluted (in dollars per share)	$ 0.06	$ (0.36)	$ (1.18)	$ (1.23)
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders:
Basic (in shares)	135,141	130,716	133,213	128,162
Diluted (in shares)	138,200	130,716	133,213	128,162