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Note 2 - Basis of Presentation and Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended		18 Months Ended	50 Months Ended
	Jun. 30, 2025 USD ($) shares	Mar. 31, 2025 USD ($)	Jun. 30, 2024 USD ($) shares	Mar. 31, 2024 USD ($)	Jun. 30, 2025 USD ($) shares	Jun. 30, 2024 USD ($) shares	Jun. 30, 2025 USD ($)	Jun. 30, 2025 USD ($) $ / shares shares	Dec. 31, 2024 USD ($)	Apr. 26, 2024 USD ($)	Sep. 22, 2023 USD ($)
Investments, Nonaccrual, Interest Income	$ 200		$ 0		$ 200	$ 0
Number of Investments with Payment in Kind Provisions	3				3		3	3	5
Investment, Payment in Kind Interest Income, Amount	$ 200		$ 400		$ 500	$ 1,700
Investment, Income Attributable to Non-cash Paid-in-Kind Interest, Percent	1.00%		1.10%		1.40%	3.30%
Interest Income, Operating, Paid in Kind					$ 528	$ 1,737
Investment, Nonaccrual, Income Not Received in Cash, Percent	2.80%		6.60%		3.70%		6.70%
Debt Issuance Costs, Net	$ 8,900				$ 8,900		$ 8,900	$ 8,900	$ 8,900
Accumulated Amortization, Debt Issuance Costs	8,600				8,600		$ 8,600	$ 8,600	7,200
Amortization of Debt Issuance Costs	$ 700		$ 400		$ 1,331	814
Federal Excise Tax, Percent	4.00%				4.00%		4.00%	4.00%
Excise and Sales Taxes	$ 400				$ 800	700
Unrecognized Tax Benefits	$ 0				$ 0		$ 0	$ 0	0
Open Tax Year					2025 2024 2023 2022
Proceeds from Issuance of Common Stock					$ 3,560	$ 29,110
Share Repurchase Program, Remaining Authorized, Amount										$ 5,000
Stock Repurchased During Period, Shares (in shares) | shares	0		0		0	0		167,465
Stock Repurchased During Period, Per Share (in dollars per share) | $ / shares								$ 11.22
Stock Repurchased During Period, Value								$ 1,900
The 2023 Equity Distribution Agreement [Member]
Equity Sales Agreement, Maximum Value											$ 150,000
Stock Issued During Period, Shares, New Issues (in shares) | shares	0		1,516,249		404,305	2,570,045
Proceeds from Issuance of Common Stock			$ 17,100		$ 3,600	$ 29,100
Payments of Stock Issuance Costs			$ 400		200	$ 600
Equity Sales Agreement, Remaining Amount Available for Issuance		$ 75,200
Six Investments [Member]
Investments, Cost, Nonaccrual Status	$ 74,800				74,800		74,800	74,800
Investments, Fair Value, Nonaccrual Status	$ 26,900				$ 26,900		$ 26,900	$ 26,900
Four Investments [Member]
Investments, Cost, Nonaccrual Status									44,800
Investments, Fair Value, Nonaccrual Status									$ 10,500
One Investment [Member]
Interest Income, Operating, Paid in Kind		$ 200		$ 1,000

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