Investments - Composition of the Company's investment portfolio, at amortized cost and fair value (with corresponding percentage of total portfolio investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Investments
Amortized Cost	$ 579,307	$ 576,178
Fair Value	$ 541,040	$ 561,693
Amortized Cost, Percentage of total portfolio investments	100.00%	100.00%
Fair Value, Percentage of total portfolio investments	100.00%	100.00%
Senior secured loans
Investments
Amortized Cost	$ 436,066	$ 415,600
Fair Value	$ 434,023	$ 423,700
Amortized Cost, Percentage of total portfolio investments	75.30%	72.10%
Fair Value, Percentage of total portfolio investments	80.20%	75.40%
Unitranche secured loans
Investments
Amortized Cost	$ 45,352	$ 70,977
Fair Value	$ 20,633	$ 51,494
Amortized Cost, Percentage of total portfolio investments	7.80%	12.30%
Fair Value, Percentage of total portfolio investments	3.80%	9.20%
Junior secured loans
Investments
Amortized Cost	$ 21,141	$ 14,317
Fair Value	$ 22,193	$ 14,364
Amortized Cost, Percentage of total portfolio investments	3.60%	2.50%
Fair Value, Percentage of total portfolio investments	4.10%	2.60%
LLC equity interest in SLF
Investments
Amortized Cost	$ 42,650	$ 42,150
Fair Value	$ 35,509	$ 41,125
Amortized Cost, Percentage of total portfolio investments	7.40%	7.30%
Fair Value, Percentage of total portfolio investments	6.60%	7.30%
Equity securities
Investments
Amortized Cost	$ 34,098	$ 33,134
Fair Value	$ 28,682	$ 31,010
Amortized Cost, Percentage of total portfolio investments	5.90%	5.80%
Fair Value, Percentage of total portfolio investments	5.30%	5.50%

Represents the percentage of total portfolio investments for amortized cost.

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Represents the percentage of total portfolio investments for fair value.

+ References

No definition available.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Cost of the investment.

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Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

+ References

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