Segment Reporting - Reconciliation of net loss to Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Reconciliation of net loss to Adjusted EBITDA
Net loss	$ (14,310)	$ (14,437)	$ (6,529)	$ (10,979)	$ (28,747)	$ (17,508)
Interest expense, net	4,668		4,308		9,278	7,001
Income tax benefit	(508)		(2,539)		(3,875)	(6,580)
Depreciation and amortization	10,211		9,078		20,124	15,377
Change in fair value of acquisition-related contingent consideration (income) expense	(100)		1,830		600	3,006
Acquisition-related expense			598		251	4,289
Stock-based compensation expense	7,173		6,906		14,310	13,758
Adjusted EBITDA	$ 7,134		$ 13,652		$ 11,941	$ 19,343