Marketable Securities: Estimated fair value of marketable securities aggregated by fair value hierarchy inputs used in estimating their fair values (Details) - USD ($)	Jun. 30, 2023	Mar. 31, 2023
Marketable Securities	$ 53,187,406	$ 52,544,283
Money Market Funds
Marketable Securities	1,294,300	906,141
Corporate Bond Securities
Marketable Securities	51,893,106	51,638,142
Fair Value, Inputs, Level 1
Marketable Securities	1,294,300	906,141
Fair Value, Inputs, Level 1 | Money Market Funds
Marketable Securities	1,294,300	906,141
Fair Value, Inputs, Level 1 | Corporate Bond Securities
Marketable Securities	0	0
Fair Value, Inputs, Level 2
Marketable Securities	51,893,106	51,638,142
Fair Value, Inputs, Level 2 | Money Market Funds
Marketable Securities	0	0
Fair Value, Inputs, Level 2 | Corporate Bond Securities
Marketable Securities	$ 51,893,106	$ 51,638,142