Note 4 - Investments - Securities Measured and Carried at Fair Value on Recurring Basis With Significant Unobservable Inputs (Details) $ in Thousands		Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)
Investments in debt securities	[1]	$ 4,414
Convertible Debt Securities [Member]
Investments in debt securities		$ 4,414	$ 7,008
Valuation Technique, Option Pricing Model [Member] | Measurement Input, Price Volatility [Member]
Investments in equity securities, unobservable inputs			1
Valuation Technique, Option Pricing Model [Member] | Measurement Input, Risk Free Interest Rate [Member]
Investments in equity securities, unobservable inputs			0.05
Valuation Technique, Option Pricing Model [Member] | Common Shares Purchase Warrants [Member]
Investments in debt securities			$ 290
Valuation Technique, Binomial Lattice Model [Member] | Measurement Input, Price Volatility [Member]
Investments in debt securities, unobservable input		0.95
Investments in equity securities, unobservable inputs			1
Valuation Technique, Binomial Lattice Model [Member] | Measurement Input, Risk Free Interest Rate [Member]
Investments in debt securities, unobservable input		0.041
Investments in equity securities, unobservable inputs			0.042
Valuation Technique, Binomial Lattice Model [Member] | Measurement Input, Credit Spread [Member]
Investments in debt securities, unobservable input		0.082
Investments in equity securities, unobservable inputs			0.115
Valuation Technique, Binomial Lattice Model [Member] | Convertible Debt Securities [Member]
Investments in debt securities		$ 4,414
Valuation Technique, Binomial Lattice Model [Member] | Unsecured Convertible Debentures [Member]
Investments in debt securities			$ 7,008

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