CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Service revenue, net (includes $11.1 million, $24.1 million and $24.0 million with related parties for the years ended December 31, 2017, 2016 and 2015, respectively)	$ 386,462	$ 370,621	$ 320,101
Reimbursed out-of-pocket revenue (includes $1.5 million, $5.4 million and $6.9 million with related parties for years ended December 31, 2017, 2016 and 2015, respectively)	49,690	50,961	38,958
Total revenue	436,152	421,582	359,059
Operating expenses:
Direct costs, excluding depreciation and amortization	211,773	198,510	163,707
Reimbursed out-of-pocket expenses (includes $1.5 million, $5.4 million and $6.9 million with related parties for years ended December 31, 2017, 2016 and 2015, respectively)	49,690	50,961	38,958
Selling, general and administrative	63,357	61,507	56,998
Impairment of goodwill	0	0	9,313
Depreciation	8,574	7,442	6,379
Amortization	37,900	50,672	63,142
Total operating expenses	371,294	369,092	338,497
Income from operations	64,858	52,490	20,562
Other expense, net:
Loss on extinguishment of debt	0	(10,726)	0
Miscellaneous expense, net	(354)	(423)	(1,133)
Interest expense, net	(7,559)	(19,384)	(27,259)
Total other expense, net	(7,913)	(30,533)	(28,392)
Income (loss) before income taxes	56,945	21,957	(7,830)
Income tax provision	17,823	8,532	843
Net income (loss)	$ 39,122	$ 13,425	$ (8,673)
Net income (loss) per share attributable to common shareholders:
Basic	$ 1.00	$ 0.38	$ (0.28)
Diluted	$ 0.98	$ 0.37	$ (0.28)
Weighted average common shares outstanding:
Basic	39,056	35,690	31,346
Diluted	39,839	36,329	31,346