Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenues	$ 225,010	$ 198,349	$ 674,135	$ 566,893
Cost of Revenues	192,535	173,199	574,655	497,539
Gross Profit	32,475	25,150	99,480	69,354
Selling, General and Administrative Expenses	15,694	14,136	45,429	45,557
Amortization Expense	321	332	980	990
Operating Income	16,460	10,682	53,071	22,807
Interest and Other Expense	3,659	3,482	9,047	14,786
Income Before Provision for Income Taxes	12,801	7,200	44,024	8,021
Provision for Income Taxes	218	2,437	8,393	2,498
Net Income	$ 12,583	$ 4,763	$ 35,631	$ 5,523
Earnings per Common Share:
Basic (in dollars per share)	$ 0.42	$ 0.16	$ 1.18	$ 0.18
Diluted (in dollars per share)	$ 0.41	$ 0.16	$ 1.17	$ 0.18
Weighted Average Shares Outstanding:
Basic (in shares)	30,219	29,875	30,219	29,874
Diluted (in shares)	30,638	30,487	30,575	30,379