CONDENSED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (Unaudited) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
CONDENSED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (Unaudited) [Abstract]
Revenue	$ 21,110,452	$ 20,854,627	$ 41,037,885	$ 40,575,722
Cost of sales	16,874,205	15,085,983	32,361,068	29,842,692
Gross profit	4,236,247	5,768,644	8,676,817	10,733,030
Selling, general and administrative expenses	1,496,272	1,570,231	3,374,195	3,675,112
Income from operations	2,739,975	4,198,413	5,302,622	7,057,918
Interest expense	155,699	174,394	297,071	323,580
Income before provision for income taxes	2,584,276	4,024,019	5,005,551	6,734,338
Provision for income taxes	800,000	1,328,000	1,550,000	2,119,000
Net income	1,784,276	2,696,019	3,455,551	4,615,338
Other comprehensive income (loss), net of tax - Change in unrealized gain (loss)-
interest rate swap	13,679	(7,058)	17,390	(32,336)
Comprehensive Income	$ 1,797,955	$ 2,688,961	$ 3,472,941	$ 4,583,002
Income per common share - basic (in dollars per share)	$ 0.21	$ 0.37	$ 0.41	$ 0.65
Income per common share - diluted (in dollars per share)	$ 0.21	$ 0.36	$ 0.41	$ 0.63
Shares used in computing income per common share:
Basic (in shares)	8,391,954	7,222,554	8,384,844	7,087,732
Diluted (in shares)	8,456,156	7,414,273	8,452,064	7,280,294