Statements of Assets and Liabilities (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Investment cost	$ 1,189,693	$ 1,150,602
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
U.S.Treasury Bills
Investment cost	$ 34,978	$ 0
Non-control/non-affiliate investments
Investment cost	1,080,015	1,126,879
Affiliate investments
Investment cost	55,528	4,551
Control investments
Investment cost	$ 19,172	$ 19,172