Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Contract revenues	$ 143,105	$ 136,843
Costs of contract revenues	132,886	121,021
Gross profit	10,219	15,822
Selling, general and administrative expenses	16,770	15,014
Gain on sale of assets, net	(374)	(813)
Other gain from continuing operations	0	5,448
Operating (loss) income from operations	(6,177)	7,069
Other (expense) income:
Other income (expense)	23	(2)
Interest income	148	0
Interest expense	(1,325)	(1,477)
Other expense, net	(1,154)	(1,479)
(Loss) income before income taxes	(7,331)	5,590
Income tax expense	593	1,489
Net (loss) income	$ (7,924)	$ 4,101
Basic (loss) income per share (in dollars per share)	$ (0.27)	$ 0.15
Diluted (loss) income per share (in dollars per share)	$ (0.27)	$ 0.14
Shares used to compute (loss) income per share:
Basic (in shares)	28,927,406	28,143,791
Diluted (in shares)	28,927,406	28,369,762