Consolidated Statements of Assets And Liabilities (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Cash equivalents at cost	$ 447,074	$ 397,510
Debt instrument, face amount	1,048,260	1,041,093
Debt issuance costs	$ 8,848	$ 9,399
Common stock, par or stated value per share	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares, issued	54,554,634	54,554,634
Common stock, shares, outstanding	54,554,634	54,554,634
Companies less than 5% owned [Member]
Investment owned, at cost	$ 1,015,960	$ 1,019,357
Companies 5% to 25% owned [Member]
Investment owned, at cost	105,224	103,655
Companies more than 25% owned [Member]
Investment owned, at cost	$ 918,904	$ 916,554