STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues	$ 25,223,534	$ 24,089,608	$ 20,108,862
Cost of revenues	10,971,886	9,616,985	8,067,229
Gross profit	14,251,648	14,472,623	12,041,633
Operating Expenses:
General & administrative	3,946,844	3,948,706	4,195,998
Marketing & selling	4,543,598	4,116,059	2,949,739
Research & development	825,518	607,408	481,433
Total Operating Expenses	9,315,960	8,672,173	7,627,170
Operating income	4,935,688	5,800,450	4,414,463
Interest income	1,889	5,346	23,091
Net income before provision for income taxes	4,937,577	5,805,796	4,437,554
Provision for income taxes	1,957,948	2,316,513	1,823,834
Net income and comprehensive income	$ 2,979,629	$ 3,489,283	$ 2,613,720
Basic net income per share (in dollars per share)	$ 0.57	$ 0.67	$ 0.50
Diluted net income per share (in dollars per share)	$ 0.57	$ 0.67	$ 0.50
Dividends declared per share (in dollars per share)	$ 0.60	$ 0.48	$ 0.48
Weighted average common shares outstanding, basic (in shares)	5,260,320	5,229,646	5,207,244
Weighted average common shares outstanding, diluted (in shares)	5,272,542	5,235,940	5,226,454