Note 2 - Investments - Securities Measured and Carried at Fair Value on Recurring Basis With Significant Unobservable Inputs (Details) $ in Thousands		Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)
Investments in debt securities	[1]	$ 3,742
Convertible Debt Securities [Member]
Investments in debt securities		$ 3,742	$ 4,414
Valuation Technique, Binomial Lattice Model [Member] | Measurement Input, Price Volatility [Member]
Investments in debt securities, unobservable input		0.90
Investments in equity securities, unobservable inputs			0.95
Valuation Technique, Binomial Lattice Model [Member] | Measurement Input, Risk Free Interest Rate [Member]
Investments in debt securities, unobservable input		0.0315
Valuation Technique, Binomial Lattice Model [Member] | Measurement Input, Credit Spread [Member]
Investments in debt securities, unobservable input		0.079
Investments in equity securities, unobservable inputs			0.041
Valuation Technique, Binomial Lattice Model [Member] | Unsecured Convertible Debentures [Member]
Investments in debt securities			$ 4,414
Valuation Technique, Binomial Lattice Model [Member] | Convertible Debt Securities [Member]
Investments in debt securities		$ 3,742
Valuation Technique, Option Pricing Model [Member] | Measurement Input, Risk Free Interest Rate [Member]
Investments in equity securities, unobservable inputs			0.082

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