Statements of Income (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue	$ 6,823,462	$ 4,380,785	$ 13,976,625	$ 8,970,047
Cost of sales	1,544,134	941,287	3,313,715	1,777,709
Gross profit	5,279,328	3,439,498	10,662,910	7,192,338
Expenses
Research and development	707,997	815,965	1,516,139	1,696,948
Selling, general, and administrative	483,116	358,182	949,734	713,193
Total expenses	1,191,113	1,174,147	2,465,873	2,410,141
Income from operations	4,088,215	2,265,351	8,197,037	4,782,197
Interest income	294,858	401,392	584,578	800,604
Income before taxes	4,383,073	2,666,743	8,781,615	5,582,801
Provision for income taxes	736,566	444,403	1,555,542	948,596
Net income	$ 3,646,507	$ 2,222,340	$ 7,226,073	$ 4,634,205
Net income per share – basic (in dollars per share)	$ 0.75	$ 0.46	$ 1.50	$ 0.96
Net income per share – diluted (in dollars per share)	0.75	0.46	1.49	0.96
Cash dividends declared per common share (in dollars per share)	$ 1.00	$ 1.00	$ 2.00	$ 2.00
Weighted average shares outstanding
Weighted average common shares outstanding – basic (in shares)	4,833,232	4,834,709	4,833,232	4,834,872
Diluted (in shares)	4,836,603	4,834,809	4,836,621	4,834,986
Revenue	$ 6,823,462	$ 4,380,785	$ 13,976,625	$ 8,970,047
Cost of sales	1,544,134	941,287	3,313,715	1,777,709
Gross profit	5,279,328	3,439,498	10,662,910	7,192,338
Product [Member]
Revenue	6,630,012	4,159,173	13,583,778	8,517,808
Weighted average shares outstanding
Revenue	6,630,012	4,159,173	13,583,778	8,517,808
Contract Research and Development [Member]
Revenue	193,450	221,612	392,847	452,239
Weighted average shares outstanding
Revenue	$ 193,450	$ 221,612	$ 392,847	$ 452,239