Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenue	$ 490,559	$ 490,280	$ 501,867
Cost of revenue	410,402	408,288	412,292
Gross profit	80,157	81,992	89,575
Selling, general and administrative expenses	48,597	47,748	47,108
Restructuring charges	0	1,551	0
Gain (loss) on change in fair value of contingent consideration, net	(136)	(371)	1,392
Operating income	31,424	32,322	43,859
Interest expense	1,568	1,381	833
Other income (expense) (including interest income of $94 in 2016, $149 in 2015 and $112 in 2014)	178	(1,318)	(203)
Income before income taxes	30,034	29,623	42,823
Income tax expense	9,787	10,834	15,725
Net income	$ 20,247	$ 18,789	$ 27,098
Basic weighted average shares outstanding (in shares)	16,696	17,110	18,641
Diluted weighted average shares outstanding (in shares)	16,791	17,264	18,887
Per common share data:
Basic earnings per share (in dollars per share)	$ 1.21	$ 1.10	$ 1.45
Diluted earnings per share (in dollars per share)	$ 1.21	$ 1.09	$ 1.43