Quarterly Results of Operations (unaudited) - Schedule of Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Results of Operations (unaudited)
Total Revenue	$ 71,003	$ 79,725	$ 56,234	$ 47,608	$ 64,799	$ 52,495	$ 49,554	$ 45,432	$ 254,570	$ 212,280	$ 193,291
Gross profit	49,629	53,056	38,354	31,569	42,246	34,543	35,981	34,697	172,608	147,467	134,514
Operating costs	43,735	35,937	40,565	37,096	38,145	37,657	38,592	33,049	157,333	147,443	128,322
Operating income (loss)	5,894	17,119	(2,211)	(5,527)	4,101	(3,114)	(2,611)	1,648	15,275	24	6,192
Provision (benefit) for income taxes	2,343	3,864	770	(272)	650	(1,702)	(872)	629
Net income (loss)	$ 5,050	$ 11,872	$ (2,461)	$ (5,671)	$ 3,964	$ (908)	$ (1,002)	$ 1,792	$ 8,789	$ 3,846	$ (22,399)
Net income/(loss) per share:
Basic (in dollars per share)	$ 0.13	$ 0.30	$ (0.06)	$ (0.14)	$ 0.10	$ (0.02)	$ (0.03)	$ 0.04	$ 0.22	$ 0.10	$ (0.56)
Diluted (in dollars per share)	$ 0.13	$ 0.30	$ (0.06)	$ (0.14)	$ 0.10	$ (0.02)	$ (0.03)	$ 0.04	$ 0.22	$ 0.10	$ (0.56)