Investments - Composition of the Company's Investment Portfolio by Geographic Region, at Amortized Cost and Fair Value (with Corresponding Percentage of Total Portfolio Investments) (Details) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2024		Dec. 31, 2023
Investments
Investment owned, cost	$ 505,008,000	[1]	$ 510,876,000	[2]
Fair Value	$ 474,259,000	[1],[3]	$ 488,386,000	[2],[4]
Investment Owned, At Cost | Geographic Concentration Risk
Investments
Concentration risk, percentage	100.00%		100.00%
Investment Owned, At Fair Value | Geographic Concentration Risk
Investments
Concentration risk, percentage	100.00%		100.00%
Midwest
Investments
Investment owned, cost	$ 164,048,000		$ 158,383,000
Fair Value	$ 139,091,000		$ 135,352,000
Midwest | Investment Owned, At Cost | Geographic Concentration Risk
Investments
Concentration risk, percentage	32.50%		31.00%
Midwest | Investment Owned, At Fair Value | Geographic Concentration Risk
Investments
Concentration risk, percentage	29.30%		27.70%
Northeast
Investments
Investment owned, cost	$ 108,660,000		$ 108,707,000
Fair Value	$ 107,549,000		$ 110,180,000
Northeast | Investment Owned, At Cost | Geographic Concentration Risk
Investments
Concentration risk, percentage	21.50%		21.30%
Northeast | Investment Owned, At Fair Value | Geographic Concentration Risk
Investments
Concentration risk, percentage	22.80%		22.60%
Southeast
Investments
Investment owned, cost	$ 123,177,000		$ 134,899,000
Fair Value	$ 117,805,000		$ 130,595,000
Southeast | Investment Owned, At Cost | Geographic Concentration Risk
Investments
Concentration risk, percentage	24.40%		26.40%
Southeast | Investment Owned, At Fair Value | Geographic Concentration Risk
Investments
Concentration risk, percentage	24.80%		26.80%
Southwest
Investments
Investment owned, cost	$ 19,005,000		$ 25,163,000
Fair Value	$ 19,550,000		$ 25,610,000
Southwest | Investment Owned, At Cost | Geographic Concentration Risk
Investments
Concentration risk, percentage	3.80%		4.90%
Southwest | Investment Owned, At Fair Value | Geographic Concentration Risk
Investments
Concentration risk, percentage	4.10%		5.20%
West
Investments
Investment owned, cost	$ 90,118,000		$ 83,724,000
Fair Value	$ 88,718,000		$ 84,954,000
West | Investment Owned, At Cost | Geographic Concentration Risk
Investments
Concentration risk, percentage	17.80%		16.40%
West | Investment Owned, At Fair Value | Geographic Concentration Risk
Investments
Concentration risk, percentage	18.70%		17.30%
International
Investments
Investment owned, cost	$ 0		$ 0
Fair Value	1,546,000		1,695,000
International | One International Portfolio Investment
Investments
Investment owned, cost	$ 0		$ 0
International | Investment Owned, At Cost | Geographic Concentration Risk
Investments
Concentration risk, percentage	0.00%		0.00%
International | Investment Owned, At Fair Value | Geographic Concentration Risk
Investments
Concentration risk, percentage	0.30%		0.30%

[1] All of the Company’s investments are issued by eligible portfolio companies, as defined in the Investment Company Act of 1940 (the “1940 Act”), unless otherwise noted. All of the Company’s investments are issued by U.S. portfolio companies unless otherwise noted.

[2] All of the Company's investments are issued by eligible portfolio companies, as defined in the Investment Company Act of 1940 (the “1940 Act”), unless otherwise noted. All of the Company's investments are issued by U.S. portfolio companies unless otherwise noted.

[3] Because there is no readily available market value for these investments, the fair value of these investments is determined in good faith using significant unobservable inputs by the Valuation Designee. (See Note 4 in the accompanying notes to the consolidated financial statements).

[4] Because there is no readily available market value for these investments, the fair value of these investments is determined in good faith using significant unobservable inputs by the Valuation Designee. (See Note 4 in the accompanying notes to the consolidated financial statements.)