Quarterly Financial Data (Unaudited) - Schedule of Unaudited Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Service revenue, net	$ 95,376	$ 94,812	$ 92,633	$ 87,800	$ 85,681	$ 81,638	$ 76,752	$ 76,030	$ 219,791	$ 370,621	$ 320,101
Direct costs, excluding depreciation and amortization	51,074	51,221	49,234	46,981	44,219	41,763	38,600	39,125	117,550	198,510	163,707
Income (loss) from operations	12,890	12,617	14,114	12,869	(889)	7,195	7,867	6,389	2,447	52,490	20,562
Net income (loss)	$ (21)	$ 5,036	$ 4,962	$ 3,448	$ (8,576)	$ (133)	$ 95	$ (59)	$ (14,336)	$ 13,425	$ (8,673)
Net income (loss) per common share—Basic	$ 0.00	$ 0.14	$ 0.15	$ 0.11	$ (0.27)	$ 0.00	$ 0.00	$ 0.00	$ (0.46)	$ 0.38	$ (0.28)
Net income (loss) per common share—Diluted	$ 0.00	$ 0.13	$ 0.15	$ 0.11	$ (0.27)	$ 0.00	$ 0.00	$ 0.00	$ (0.46)	$ 0.37	$ (0.28)