Consolidated Statements of Assets and Liabilities (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Investment cost	$ 1,062,789	$ 1,106,849
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Non-control/non-affiliate investments
Investment cost	$ 1,002,897	$ 1,005,024
Affiliate investments
Investment cost	58,942	58,861
Control investments
Investment cost	950	950
U.S. Treasury Bills
Investment cost	$ 0	$ 42,014