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Note 6 - Fair Value - Significant Level 3 Fair Value Measurement Inputs (Details) - Fair Value, Inputs, Level 3 [Member] $ in Thousands		Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Investments, fair value		$ 620,990	$ 695,465
Investments, measurement input		3.99
Debt [Member] | Valuation Technique, Discounted Cash Flow [Member]
Investments, fair value		$ 540,426	$ 628,325
Debt [Member] | Valuation Technique, Discounted Cash Flow [Member] | Minimum [Member] | Hypothetical Market Yield [Member]
Investments, measurement input		0.10	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]	0.13	0.14
Debt [Member] | Multiple Probability Weighted Cash Flow Model [Member]
Investments, fair value		$ 38,745	$ 10,454
Debt [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Minimum [Member] | Probability Weighting [Member]
Investments, measurement input		0	0.10
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]	0.47	0.57
Warrant [Member] | Black-scholes Valuation Model [Member]
Investments, fair value		$ 15,193	$ 16,438
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]	16.26	16.8
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	0.15
Warrant [Member] | Black-scholes Valuation Model [Member] | Weighted Average [Member] | Estimated Time to Exit [Member]
Investments, measurement input	[1]	3	3
Warrant [Member] | Expected Proceeds [Member]
Investments, fair value		$ 2,712
Warrant [Member] | Expected Proceeds [Member] | Measurement Input, Share Price [Member]
Investments, measurement input		32.69
Warrant [Member] | Expected Proceeds [Member] | Weighted Average [Member] | Measurement Input, Share Price [Member]
Investments, measurement input	[1]	32.69
Other Investments [Member] | Minimum [Member]
Investments, measurement input			0.15
Other Investments [Member] | Maximum [Member]
Investments, measurement input			0.25
Other Investments [Member] | Multiple Probability Weighted Cash Flow Model [Member]
Investments, fair value		$ 8,451	$ 14,637
Other Investments [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Minimum [Member] | Probability Weighting [Member]
Investments, measurement input		0	0.30
Other Investments [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Minimum [Member] | Measurement Input, Discount Rate [Member]
Investments, measurement input		0.25
Other Investments [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Maximum [Member] | Probability Weighting [Member]
Investments, measurement input		1	1
Other Investments [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Maximum [Member] | Measurement Input, Discount Rate [Member]
Investments, measurement input		0.30
Other Investments [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Weighted Average [Member] | Probability Weighting [Member]
Investments, measurement input		0.97	0.90	[1]
Other Investments [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Weighted Average [Member] | Measurement Input, Discount Rate [Member]
Investments, measurement input	[1]	0.26	0.18
Equity Securities [Member] | Multiple Probability Weighted Cash Flow Model [Member] | Weighted Average [Member] | Probability Weighting [Member]
Investments, measurement input	[1]	3.99
Equity Securities [Member] | Multiple Probability Weighted Scenario Model [Member]
Investments, fair value		$ 2,551
Equity Securities [Member] | Multiple Probability Weighted Scenario Model [Member] | Probability Weighting [Member]
Investments, fair value		$ 1,281	$ 3,963
Equity Securities [Member] | Multiple Probability Weighted Scenario Model [Member] | Minimum [Member] | Probability Weighting [Member]
Investments, measurement input		0.20	0.10
Equity Securities [Member] | Multiple Probability Weighted Scenario Model [Member] | Maximum [Member] | Probability Weighting [Member]
Investments, measurement input		1	1
Equity Securities [Member] | Multiple Probability Weighted Scenario Model [Member] | Weighted Average [Member] | Probability Weighting [Member]
Investments, measurement input		0.33	0.33	[1]
Equity Securities [Member] | Last Equity Financing [Member]
Investments, fair value		$ 11,631	$ 21,648
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] | Maximum [Member] | Measurement Input, Share Price [Member]
Investments, measurement input		215.03	215.03
Equity Securities [Member] | Last Equity Financing [Member] | Weighted Average [Member] | Measurement Input, Share Price [Member]
Investments, measurement input	[1]	54.69	30.47
[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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+ References

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

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