Statements Of Income (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Revenue
Product sales	$ 6,448,407	$ 5,762,925	$ 19,654,162	$ 18,025,002
Contract research and development	25,290	762,296	297,648	1,785,920
Total revenue	6,473,697	6,525,221	19,951,810	19,810,922
Cost of sales	1,449,396	1,738,618	4,331,297	5,147,884
Gross profit	5,024,301	4,786,603	15,620,513	14,663,038
Expenses
Selling, general , and administrative	543,698	570,741	1,756,578	1,714,545
Research and development	905,246	501,325	2,744,620	1,801,609
Total expenses	1,448,944	1,072,066	4,501,198	3,516,154
Income from operations	3,575,357	3,714,537	11,119,315	11,146,884
Interest income	530,383	600,395	1,577,524	1,784,963
Income before taxes	4,105,740	4,314,932	12,696,839	12,931,847
Provision for income taxes	1,328,566	1,415,590	4,123,189	4,211,964
Net income	$ 2,777,174	$ 2,899,342	$ 8,573,650	$ 8,719,883
Net income per share - basic	$ 0.57	$ 0.60	$ 1.77	$ 1.80
Net income per share - diluted	$ 0.57	$ 0.60	$ 1.76	$ 1.80
Weighted average shares outstanding
Basic	4,842,565	4,847,619	4,852,356	4,832,630
Diluted	4,859,601	4,872,019	4,868,040	4,856,851