Note 4 - Investments - Securities Measured and Carried at Fair Value on Recurring Basis With Significant Unobservable Inputs (Details) $ in Thousands		Jun. 30, 2022 USD ($)		Jun. 30, 2021 USD ($)
Investments in equity securities		$ 14,300		$ 18,258
Investments in debt securities	[1]	$ 10,625	[2]	$ 17,049
Measurement Input, Price Volatility [Member]
Investments in equity securities, unobservable inputs		1.034
Investments in debt securities, unobservable input		0.959
Measurement Input, Discount Rate [Member]
Investments in debt securities, unobservable input		0.047
Valuation Technique, Option Pricing Model [Member]
Investments in equity securities		$ 515
Valuation Technique, Binomial Lattice Model [Member]
Investments in debt securities		$ 10,625

[1] Changes in unrealized gains and losses are included in the statement of comprehensive income (loss), except for embedded derivatives. Changes in unrealized and realized gains and losses for embedded derivatives are included in earnings in the statement of operations.

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