Consolidated Statements of Assets and Liabilities (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Non-controlled non-affiliated investments at cost	$ 1,242,938	$ 1,150,173
Non-controlled affiliated investment at cost	48,920	41,242
Controlled investments at cost	22,837	53,431
Deferred financing costs, net	$ 5,818	$ 6,897
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, authorized	10,000	10,000
Preferred stock, outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, authorized	200,000,000	200,000,000
Common stock, issued	30,887,360	30,887,360
Common stock, outstanding	30,887,360	30,887,360