Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenues	$ 233,391	$ 195,127	$ 449,126	$ 368,543
Cost of Revenues	197,507	172,426	382,121	324,339
Gross Profit	35,884	22,701	67,005	44,204
Selling, General and Administrative Expenses	14,433	14,802	29,736	31,421
Amortization Expense	327	331	659	658
Operating Income	21,124	7,568	36,610	12,125
Interest and Other Expense	3,428	6,740	5,388	11,304
Income Before Provision for Income Taxes	17,696	828	31,222	821
Provision for Income Taxes	4,501	697	8,174	61
Net Income	$ 13,195	$ 131	$ 23,048	$ 760
Earnings per Common Share:
Basic (in dollars per share)	$ 0.44	$ 0.00	$ 0.76	$ 0.03
Diluted (in dollars per share)	$ 0.43	$ 0.00	$ 0.75	$ 0.03
Weighted Average Shares Outstanding:
Basic (in shares)	30,219	29,874	30,219	29,873
Diluted (in shares)	30,513	30,455	30,543	30,325