CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Net revenue	$ 249,901	$ 235,942
Costs and expenses:
Cost of revenue (exclusive of depreciation and amortization shown separately below)	16,847	14,265
Sales and marketing	137,297	124,316
Product development	67,113	58,075
General and administrative	43,536	31,292
Depreciation and amortization	12,358	11,876
Total costs and expenses	277,151	239,824
Loss from operations	(27,250)	(3,882)
Other income, net	2,383	4,691
(Loss) income before income taxes	(24,867)	809
Benefit from income taxes	(9,364)	(556)
Net (loss) income attributable to common stockholders	$ (15,503)	$ 1,365
Net (loss) income per share attributable to common stockholders
Basic (in USD per share)	$ (0.22)	$ 0.02
Diluted (in USD per share)	$ (0.22)	$ 0.02
Weighted-average shares used to compute net (loss) income per share attributable to common stockholders
Basic (in shares)	71,548	81,772
Diluted (in shares)	71,548	85,087