Note 7 - Other Assets - Investments (Details) - USD ($)	Mar. 31, 2023	Jun. 30, 2022
Investments, cost	$ 8,769,566	$ 5,039,309
Investments, gross unrealized gains	66,119	32,697
Investments, gross unrealized losses	(132,195)	(6,075)
Investments	8,703,490	5,065,931
Short-term treasury bills	8,703,490	5,065,931
Money Market Funds [Member]
Investments, cost	3,036,823	1,051,017
Investments, gross unrealized gains	0	0
Investments, gross unrealized losses	0	0
Investments	3,036,823	1,051,017
Short-term treasury bills	3,036,823	1,051,017
Other Short Term Investments [Member]
Investments, cost	277,271	271,346
Investments, gross unrealized gains	0	0
Investments, gross unrealized losses	(661)	(1,919)
Investments	276,610	269,427
Short-term treasury bills	276,610	269,427
US Treasury and Government Short-Term Debt Securities [Member]
Investments, cost	1,958,546	2,470,020
Investments, gross unrealized gains	13,374	0
Investments, gross unrealized losses	0	(4,156)
Investments	1,971,920	2,465,864
Short-term treasury bills	1,971,920	2,465,864
Other Equities [Member]
Investments, cost	3,496,926	1,246,926
Investments, gross unrealized gains	52,745	32,697
Investments, gross unrealized losses	(131,534)	0
Investments	3,418,137	1,279,623
Short-term treasury bills	$ 3,418,137	$ 1,279,623