CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Unaudited)) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenue	$ 16,731,951	$ 22,280,964	$ 36,764,652	$ 34,950,997
Cost of sales	13,048,203	17,246,963	28,543,390	41,556,100
Gross profit (loss)	3,683,748	5,034,001	8,221,262	(6,605,103)
Selling, general and administrative expenses	2,002,198	1,868,787	4,166,076	4,589,170
Income (loss) from operations	1,681,550	3,165,214	4,055,186	(11,194,273)
Interest expense	465,903	323,634	856,238	599,367
Income (loss) before provision for (benefit from) income taxes	1,215,647	2,841,580	3,198,948	(11,793,640)
Provision for (benefit from) income taxes	450,000	1,051,000	1,184,000	(4,364,000)
Net income (loss)	765,647	1,790,580	2,014,948	(7,429,640)
Other comprehensive income (loss) net of tax - Change in unrealized gain (loss) interest rate swap	(1,000)	(73,936)	4,200	(70,483)
Comprehensive income (loss)	$ 764,647	$ 1,716,644	$ 2,019,148	$ (7,500,123)
Income (loss) per common share - basic (in dollars per share)	$ 0.09	$ 0.21	$ 0.23	$ (0.86)
Income (loss) per common share - diluted (in dollars per share)	$ 0.09	$ 0.21	$ 0.23	$ (0.86)
Shares used in computing income (loss) per common share:
Basic (shares)	8,832,478	8,610,453	8,806,942	8,603,495
Diluted (shares)	8,865,055	8,637,393	8,840,309	8,603,495