Investments - SLP's portfolio (Details) $ in Thousands	12 Months Ended
Dec. 31, 2023 USD ($) Borrower	Dec. 31, 2022 USD ($) Borrower
Concentration Risk [Line Items]
Investments at fair value	$ 2,298,343	$ 2,386,977
International Senior Loan Program, LLC
Concentration Risk [Line Items]
Investments at fair value	709,846	707,683
International Senior Loan Program, LLC \| Investments Operations [Member] \| Investment Concentration Risk [Member]
Concentration Risk [Line Items]
Investments at fair value	$ 709,846	$ 707,683
Weighted average yield on investments	11.30%	9.30%
Number of borrowers in ISLP \| Borrower	37	38
Unfunded commitments	$ 11,496	$ 14,212
International Senior Loan Program, LLC \| Investments Operations [Member] \| Investment Concentration Risk [Member] \| Largest Investee [Member]
Concentration Risk [Line Items]
Investments at fair value	47,432	46,687
International Senior Loan Program, LLC \| Investments Operations [Member] \| Investment Concentration Risk [Member] \| Five Largest Investee [Member]
Concentration Risk [Line Items]
Investments at fair value	$ 206,779	$ 197,270

Fair value of investment in security owned.

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Period Type:	instant