Note 3 - Investments - Securities Measured and Carried at Fair Value on Recurring Basis With Significant Unobservable Inputs (Details) $ in Thousands	Sep. 30, 2022 USD ($)		Jun. 30, 2022 USD ($)
Investments in equity securities	$ 14,206		$ 14,300
Investments in debt securities	$ 9,866	[1]	$ 10,625
Measurement Input, Price Volatility [Member]
Investments in equity securities, unobservable inputs	0.921
Investments in debt securities, unobservable input	0.942
Measurement Input, Discount Rate [Member]
Investments in debt securities, unobservable input	0.055
Valuation Technique, Option Pricing Model [Member]
Investments in equity securities	$ 535
Valuation Technique, Binomial Lattice Model [Member]
Investments in debt securities	$ 9,866

[1] Principal payments of $750,000 are due quarterly with a final maturity date in January 2026.