QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly financial data [Abstract]
Revenue	$ 21,285,992	$ 20,664,645	$ 21,110,452	$ 19,927,433	$ 27,356,029	$ 21,340,831	$ 20,854,627	$ 19,721,095	$ 82,988,522	$ 89,272,582	$ 74,135,669
Gross Profit (loss)	5,280,303	4,476,127	4,236,247	4,440,570	7,695,159	5,804,424	5,768,644	4,964,386	18,433,247	24,232,613	18,809,940
Net Income (loss)	$ 2,370,242	$ 1,911,100	$ 1,784,276	$ 1,671,276	$ 3,600,354	$ 2,795,437	$ 2,696,019	$ 1,919,320	$ 7,736,894	$ 11,011,130	$ 7,416,928
Earning (loss) per share [Abstract]
Basic (in dollars per share)	$ 0.28	$ 0.23	$ 0.21	$ 0.20	$ 0.43	$ 0.33	$ 0.37	$ 0.28	$ 0.92	$ 1.43	$ 1.08
Diluted (in dollars per share)	$ 0.28	$ 0.23	$ 0.21	$ 0.20	$ 0.43	$ 0.33	$ 0.36	$ 0.27	$ 0.91	$ 1.40	$ 1.04