CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue:
Service revenue, net (includes $2.0 million and $6.9 million with related parties for the three months ended September 30, 2017 and 2016, respectively, and $8.9 million and $19.3 million with related parties for the nine months ended September 30, 2017 and 2016, respectively)	$ 98,681	$ 94,812	$ 287,014	$ 275,245
Reimbursed out-of-pocket revenue (includes $0.2 million and $1.4 million with related parties for the three months ended September 30, 2017 and 2016, respectively, and $1.3 million and $4.3 million with related parties for the nine months ended September 30, 2017 and 2016, respectively)	11,962	12,987	36,456	38,094
Total revenue	110,643	107,799	323,470	313,339
Operating expenses:
Direct costs, excluding depreciation and amortization	53,144	51,221	156,204	147,436
Reimbursed out-of-pocket expenses (includes $0.2 million and $1.4 million with related parties for the three months ended September 30, 2017 and 2016, respectively, and $1.3 million and $4.3 million with related parties for the nine months ended September 30, 2017 and 2016, respectively)	11,962	12,987	36,456	38,094
Selling, general and administrative	16,606	16,391	46,515	44,724
Depreciation	2,237	1,915	6,468	5,481
Amortization	9,496	12,668	28,406	38,004
Total operating expenses	93,445	95,182	274,049	273,739
Income from operations	17,198	12,617	49,421	39,600
Other expense, net:
Miscellaneous expense, net	(145)	(378)	(642)	(1,319)
Interest expense, net	(1,906)	(4,656)	(5,508)	(16,550)
Total other expense, net	(2,051)	(5,034)	(6,150)	(17,869)
Income before income taxes	15,147	7,583	43,271	21,731
Income tax provision	5,316	2,547	15,440	8,285
Net income	$ 9,831	$ 5,036	$ 27,831	$ 13,446
Net income per share attributable to common shareholders:
Basic	$ 0.25	$ 0.14	$ 0.70	$ 0.39
Diluted	$ 0.25	$ 0.13	$ 0.69	$ 0.39
Weighted average common shares outstanding:
Basic	38,579	37,118	39,803	34,138
Diluted	39,329	37,623	40,537	34,365