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Note 6 - Fair Value - Significant Level 3 Fair Value Measurement Inputs (Details) - Fair Value, Inputs, Level 3 [Member] | Jun. 30, 2026 USD ($) | Dec. 31, 2025 USD ($)
--- | --- | ---
Investments, fair value |  | $ 672,031,000 | $ 641,340,000
Debt [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |
Investments, fair value |  | $ 581,983,000 | $ 558,294,000
Debt [Member] | Valuation Technique, Discounted Cash Flow [Member] | Minimum [Member] | Hypothetical Market Yield [Member] |  |  |
Investments, measurement input |  | 0.09 | 0.11
Debt [Member] | Valuation Technique, Discounted Cash Flow [Member] | Maximum [Member] | Hypothetical Market Yield [Member] |  |  |
Investments, measurement input |  | 0.20 | 0.20
Debt [Member] | Valuation Technique, Discounted Cash Flow [Member] | Weighted Average [Member] | Hypothetical Market Yield [Member] |  |  |
Investments, measurement input | [1] | 0.12 | 0.13
Debt [Member] | Multiple Probability Weighted Cash Flow Model [Member] |  |  |
Investments, fair value |  | $ 66,016,000 | $ 37,731,000
Debt [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Minimum [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input |  | 0.05 | 0.30
Debt [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Maximum [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input |  | 1 | 1
Debt [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Weighted Average [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input | [1] | 0.50 | 0.56
Warrant [Member] | Black-scholes Valuation Model [Member] |  |  |
Investments, fair value |  | $ 14,113,000 | $ 14,732,000
Warrant [Member] | Black-scholes Valuation Model [Member] | Measurement Input, Price Volatility [Member] |  |  |
Investments, measurement input |  | 0.24 | 0.24
Warrant [Member] | Black-scholes Valuation Model [Member] | Minimum [Member] | Measurement Input, Share Price [Member] |  |  |
Investments, measurement input |  | 0 | 0
Warrant [Member] | Black-scholes Valuation Model [Member] | Minimum [Member] | Measurement Input, Discount for Lack of Marketability [Member] |  |  |
Investments, measurement input |  | 0 | 0
Warrant [Member] | Black-scholes Valuation Model [Member] | Minimum [Member] | Estimated Time to Exit [Member] |  |  |
Investments, measurement input |  | 1 | 1
Warrant [Member] | Black-scholes Valuation Model [Member] | Maximum [Member] | Measurement Input, Share Price [Member] |  |  |
Investments, measurement input |  | 807.91 | 807.91
Warrant [Member] | Black-scholes Valuation Model [Member] | Maximum [Member] | Measurement Input, Discount for Lack of Marketability [Member] |  |  |
Investments, measurement input |  | 0.20 | 0.20
Warrant [Member] | Black-scholes Valuation Model [Member] | Maximum [Member] | Estimated Time to Exit [Member] |  |  |
Investments, measurement input |  | 5 | 5
Warrant [Member] | Black-scholes Valuation Model [Member] | Weighted Average [Member] | Measurement Input, Share Price [Member] |  |  |
Investments, measurement input | [1] | 11.94 | 13.72
Warrant [Member] | Black-scholes Valuation Model [Member] | Weighted Average [Member] | Measurement Input, Price Volatility [Member] |  |  |
Investments, measurement input | [1] | 0.24 | 0.24
Warrant [Member] | Black-scholes Valuation Model [Member] | Weighted Average [Member] | Measurement Input, Discount for Lack of Marketability [Member] |  |  |
Investments, measurement input | [1] | 0.20 | 0.20
Warrant [Member] | Black-scholes Valuation Model [Member] | Weighted Average [Member] | Estimated Time to Exit [Member] |  |  |
Investments, measurement input | [1] | 3 | 3
Other Investment [Member] | Minimum [Member] |  |  |
Investments, measurement input |  |  | 0.20
Other Investment [Member] | Maximum [Member] |  |  |
Investments, measurement input |  |  | 1
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] |  |  |
Investments, fair value |  | $ 4,037,000 | $ 3,444,000
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input |  | 1 |
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Minimum [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input |  |  | 0
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Minimum [Member] | Measurement Input, Discount Rate [Member] |  |  |
Investments, measurement input |  | 0.10 |
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Maximum [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input |  |  | 1
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Maximum [Member] | Measurement Input, Discount Rate [Member] |  |  |
Investments, measurement input |  | 1 |
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Weighted Average [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input | [1] | 1 | 1
Other Investment [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Weighted Average [Member] | Measurement Input, Discount Rate [Member] |  |  |
Investments, measurement input | [1] | 0.40 | 0.44
Equity Securities [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Probability Weighting [Member] |  |  |
Investments, fair value |  | $ 0 |
Investments, measurement input |  | 100 |
Equity Securities [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Weighted Average [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input |  | 100 |
Equity Securities [Member] | Last Equity Financing [Member] |  |  |
Investments, fair value |  | $ 5,882,000 | $ 27,139,000
Equity Securities [Member] | Last Equity Financing [Member] | Minimum [Member] | Measurement Input, Share Price [Member] |  |  |
Investments, measurement input |  | 0.06 | 0.06
Equity Securities [Member] | Last Equity Financing [Member] | Minimum [Member] | Measurement Input, Discount Rate [Member] |  |  |
Investments, measurement input |  | 0 |
Equity Securities [Member] | Last Equity Financing [Member] | Maximum [Member] | Measurement Input, Share Price [Member] |  |  |
Investments, measurement input |  | 1,000 | 1,000
Equity Securities [Member] | Last Equity Financing [Member] | Maximum [Member] | Measurement Input, Discount Rate [Member] |  |  |
Investments, measurement input |  | 20 |
Equity Securities [Member] | Last Equity Financing [Member] | Weighted Average [Member] | Measurement Input, Share Price [Member] |  |  |
Investments, measurement input | [1] | 663.72 | 186.54
Equity Securities [Member] | Last Equity Financing [Member] | Weighted Average [Member] | Measurement Input, Discount Rate [Member] |  |  |
Investments, measurement input | [1] | 13 |
Equity Securities [Member] | Multiple Probability Weighted Scenario Model [Member] | Probability Weighting [Member] |  |  |
Investments, fair value |  |  | $ 0
Equity Securities [Member] | Multiple Probability Weighted Scenario Model [Member] | Weighted Average [Member] | Probability Weighting [Member] |  |  |
Investments, measurement input | [1] |  | 1
[1] | Weighted average is calculated by multiplying (a) the unobservable input for each investment in the investment type by (b) (1) the fair value of the related investment in the investment type divided by (2) the total fair value of the investment type.

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