15. QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) (Detail) - Unaudited Quarterly Results (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net sales	$ 58,043,987	$ 72,539,400	$ 44,408,358	$ 53,325,918	$ 63,989,643	$ 71,020,546	$ 52,282,632	$ 52,306,275	$ 228,317,663	$ 239,599,096	$ 252,792,263
Gross margin	20,730,302	26,182,580	15,351,627	18,022,081	22,457,325	25,590,157	20,617,328	19,265,945	80,286,590	87,930,755	89,372,714
Net income	$ 2,548,077	$ 5,367,437	$ 218,564	$ 720,687	$ 273,312	$ 5,212,267	$ 2,279,700	$ 541,616	$ 8,854,765	$ 8,306,895	$ 7,683,732
Net income per common share:
Basic (in Dollars per share)	$ 0.34	$ 0.72	$ 0.03	$ 0.10	$ 0.04	$ 0.70	$ 0.30	$ 0.07	$ 1.18	$ 1.11	$ 1.14
Diluted (in Dollars per share)	$ 0.34	$ 0.72	$ 0.03	$ 0.10	$ 0.04	$ 0.70	$ 0.30	$ 0.07	$ 1.18	$ 1.11	$ 1.14