Investments - ISLP's portfolio (Details) $ in Thousands	Dec. 31, 2024 USD ($) Borrower	Dec. 31, 2023 USD ($) Borrower
Concentration Risk [Line Items]
Investments at fair value	$ 2,431,189	$ 2,298,343
International Senior Loan Program, LLC
Concentration Risk [Line Items]
Investments at fair value	655,804	709,846
International Senior Loan Program, LLC | Investments Operations [Member] | Investment Concentration Risk [Member]
Concentration Risk [Line Items]
Investments at fair value	$ 655,804	$ 709,846
Weighted average yield on investments	10.60%	11.30%
Number of borrowers in ISLP | Borrower	35	37
Unfunded commitments	$ 3,907	$ 11,496
International Senior Loan Program, LLC | Investments Operations [Member] | Investment Concentration Risk [Member] | Largest Investee [Member]
Concentration Risk [Line Items]
Investments at fair value	51,142	47,432
International Senior Loan Program, LLC | Investments Operations [Member] | Investment Concentration Risk [Member] | Five Largest Investee [Member]
Concentration Risk [Line Items]
Investments at fair value	$ 196,173	$ 206,779