Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement
Contract revenues	$ 189,433	$ 199,507	$ 539,766	$ 508,597
Costs of contract revenues	166,932	178,614	476,763	463,645
Gross profit	22,501	20,893	63,003	44,952
Selling, general and administrative expenses	15,270	14,590	47,651	44,677
Amortization of intangible assets	519	662	1,552	1,980
Gain on disposal of assets, net	(6,373)	(451)	(7,734)	(1,197)
Operating income (loss)	13,085	6,092	21,534	(508)
Other (expense) income:
Other income	115	17	251	574
Interest income	57	75	151	317
Interest expense	(1,151)	(1,678)	(3,722)	(4,981)
Other expense, net	(979)	(1,586)	(3,320)	(4,090)
Income (loss) before income taxes	12,106	4,506	18,214	(4,598)
Income tax expense	303	467	1,660	920
Net income (loss)	$ 11,803	$ 4,039	$ 16,554	$ (5,518)
Basic earnings (loss) per share (in dollars per share)	$ 0.39	$ 0.14	$ 0.55	$ (0.19)
Diluted earnings (loss) per share (in dollars per share)	$ 0.39	$ 0.14	$ 0.55	$ (0.19)
Shares used to compute income (loss) per share:
Basic (in shares)	30,372,310	29,544,288	30,020,258	29,240,979
Diluted (in shares)	30,372,310	29,547,185	30,020,258	29,240,979