Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Selected Quarterly Financial Data (unaudited) [Abstract]

Selected quarterly financial data

	Quarter Ended
	March 31,		June 30,			September 30,		December 31,
	2012		2012			2012		2012
Net sales	$	25,641,392	$	28,222,443		$	28,772,956	$	32,115,957
Gross margin		15,241,259		16,502,373			16,803,011		19,167,932
Net income		3,803,818		3,442,247			3,676,871		3,814,806
Basic net income per share	$	0.07	$	0.06		$	0.07	$	0.07
Diluted net income per share		0.07		0.06			0.07	$	0.07
	Quarter Ended
	March 31,		June 30,			September 30,		December 31,
	2011		2011			2011		2011
Net sales	$	23,116,949	$	21,198,055		$	24,383,110	$	21,329,792
Gross margin		12,208,863		12,240,492			13,103,609		6,976,273
Net income (loss)		19,732		(2,294,832	)		1,136,285		(5,901,051	)
Basic net income (loss) per share	$	0.00	$	(0.04	)	$	0.02	$	(0.11	)
Diluted net income (loss) per share		0.00		(0.04	)		0.02		(0.11	)