Statements of Income - USD ($)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue
Revenue	$ 26,472,337	$ 29,863,881
Cost of sales	5,216,112	6,274,744
Gross profit	21,256,225	23,589,137
Expenses
Research and development	4,107,692	3,702,918
Selling, general, and administrative	1,223,971	1,435,592
Total expenses	5,331,663	5,138,510
Income from operations	15,924,562	18,450,627
Interest income	1,785,277	1,558,197
Income before taxes	17,709,839	20,008,824
Provision for income taxes	3,201,903	6,096,152
Net income	$ 14,507,936	$ 13,912,672
Net income per share – basic (in dollars per share)	$ 3	$ 2.87
Net income per share – diluted (in dollars per share)	2.99	2.87
Cash dividends declared per common share (in dollars per share)	$ 4	$ 4
Weighted average shares outstanding
Basic (in shares)	4,844,010	4,841,347
Diluted (in shares)	4,850,567	4,846,212
Product [Member]
Revenue
Revenue	$ 25,291,306	$ 27,321,810
Contract Research and Development [Member]
Revenue
Revenue	$ 1,181,031	$ 2,542,071