Consolidated Statements of Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenues (includes related party revenue of $3,164 and $8,184 for the three and nine months ended September 30, 2020, respectively, and related party contra revenue of $331 and $840 for the three and nine months ended September 30 and 2019, respectively)	$ 77,247	$ 85,785	$ 214,718	$ 250,162
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization presented separately below; includes related party cost of revenue of $267 and $302 for the three months ended September 30, 2020 and 2019, respectively, and $691 and $725 for the nine months ended September 30, 2020 and 2019, respectively)	4,664	6,982	16,403	21,558
Sales and marketing (includes related party expenses of $0 and $6,279 for the three months ended September 30, 2020 and 2019, respectively, and $1,959 and $17,501 for the nine months ended September 30, 2020 and 2019, respectively)	36,254	57,430	115,366	171,122
Technology and development	10,162	12,782	34,861	43,899
General and administrative	11,315	12,842	36,252	48,938
Depreciation and amortization	5,117	4,951	15,321	15,623
Goodwill impairment	0	0	8,264	0
Total costs and operating expenses	67,512	94,987	226,467	301,140
Income (loss) from operations	9,735	(9,202)	(11,749)	(50,978)
Interest income	13	594	452	2,003
Other Income	450	0	450	0
Loss from equity method investment	(571)	(464)	(1,460)	(737)
Income (loss) from continuing operations before income taxes	9,627	(9,072)	(12,307)	(49,712)
Provision for (benefit from) income taxes	38	(263)	(132)	(1,080)
Income (loss) from continuing operations	9,589	(8,809)	(12,175)	(48,632)
Income from discontinued operations, net of taxes	2,000	1,157	1,853	2,555
Net loss	$ 11,589	$ (7,652)	$ (10,322)	$ (46,077)
Net loss per share attributable to common stockholders:
Continuing operations, basic (in dollars per share)	$ 0.09	$ (0.08)	$ (0.11)	$ (0.46)
Discontinued operations, basic (in dollars per share)	0.02	0.01	0.02	0.02
Continuing operations, diluted (in dollars per share)	0.09	(0.08)	(0.11)	(0.46)
Discontinued operations, diluted (in dollars per share)	$ 0.02	$ 0.01	$ 0.02	$ 0.02
Weighted average common shares outstanding, basic	107,693	106,239	107,418	105,510
Weighted average common shares outstanding, diluted	110,011	106,239	107,418	105,510