Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net revenue	$ 2,990,911	$ 2,218,767	$ 1,528,545
Costs and expenses:
Cost of revenue (exclusive of depreciation and amortization shown separately below)	418,858	293,797	202,908
Sales and marketing	1,048,129	774,411	522,100
Product development	775,660	536,184	395,643
General and administrative	478,734	341,294	225,566
Depreciation and amortization	420,472	236,946	134,516
Total costs and expenses	3,141,853	2,182,632	1,480,733
Income (loss) from operations	(150,942)	36,135	47,812
Other income (expense), net:
Interest income	10,571	4,971	2,895
Interest expense	(50,882)	(6,797)	0
Other, net	(23,477)	(3,104)	(1,479)
Total other income (expense), net	(63,788)	(4,930)	1,416
Income (loss) before income taxes	(214,730)	31,205	49,228
Provision (benefit) for income taxes	(49,969)	46,525	22,459
Net income (loss)	(164,761)	(15,320)	26,769
Accretion of redeemable noncontrolling interest	(1,383)	(427)	0
Net income (loss) attributable to common stockholders	$ (166,144)	$ (15,747)	$ 26,769
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ (1.29)	$ (0.13)	$ 0.24
Diluted (in dollars per share)	$ (1.29)	$ (0.13)	$ 0.23
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders:
Basic (in shares)	129,024	122,800	113,643
Diluted (in shares)	129,024	122,800	118,944