CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Contract revenues	$ 1,061,681	$ 943,967	$ 902,729
Contract costs	939,340	811,553	777,852
Gross profit	122,341	132,414	124,877
Selling, general and administrative expenses	79,186	73,818	69,818
Amortization of intangible assets	571	334	335
Gain on sale of property and equipment	(2,257)	(142)	(893)
Income from operations	44,841	58,404	55,617
Other income (expense):
Interest income	25	106	9
Interest expense	(741)	(722)	(727)
Other, net	174	162	(27)
Income before provision for income taxes	44,299	57,950	54,872
Income tax expense	16,997	21,406	20,113
Net income	$ 27,302	$ 36,544	$ 34,759
Income per common share:
- Basic (in dollars per share)	$ 1.33	$ 1.73	$ 1.65
- Diluted (in dollars per share)	$ 1.30	$ 1.69	$ 1.61
Weighted average number of common shares and potential common shares outstanding:
- Basic (in shares)	20,577	20,922	20,821
- Diluted (in shares)	21,038	21,466	21,431
Net income	$ 27,302	$ 36,544	$ 34,759
Other comprehensive income:
Foreign currency translation adjustment	103	13	0
Other comprehensive income	103	13	0
Total comprehensive income	$ 27,405	$ 36,557	$ 34,759