Consolidated Statements of Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenues (includes related party revenue of $1,247 and $163 for the three months ended March 31, 2020 and 2019, respectively)	$ 83,526	$ 85,582
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization presented separately below; includes related party cost of revenue of $285 and $134 for the three months ended March 31, 2020 and 2019, respectively)	7,221	8,936
Sales and marketing (includes related party expenses of $1,959 and $5,473 for the three months ended March 31, 2020 and 2019, respectively)	46,575	54,738
Technology and development	12,216	15,654
General and administrative	12,312	15,104
Depreciation and amortization	6,271	6,415
Goodwill impairment	10,187	0
Total costs and operating expenses	94,782	100,847
Loss from operations	(11,256)	(15,265)
Interest income	533	1,001
Loss from equity method investment	(382)	0
Loss before income taxes	(11,105)	(14,264)
(Benefit from) provision for income taxes	(436)	101
Net loss	$ (10,669)	$ (14,365)
Net loss per share attributable to common stockholders:
Net loss per share, basic and diluted (in dollars per share)	$ (0.10)	$ (0.14)
Weighted average common shares outstanding, basic and diluted (in shares)	107,024	104,788
Other comprehensive loss:
Comprehensive loss	$ (10,669)	$ (14,365)