Investments - Summary of Investments at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Summary Of Investment Holdings [Line Items]
Cost	$ 1,601,015	$ 1,592,688
Fair Value	1,591,433	1,582,075
Unrealized Appreciation/ (Depreciation)	(9,582)	(10,613)
Senior Secured First Lien
Summary Of Investment Holdings [Line Items]
Cost	414,044	436,249
Fair Value	401,668	429,210
Unrealized Appreciation/ (Depreciation)	(12,376)	(7,039)
Unitranche First Lien
Summary Of Investment Holdings [Line Items]
Cost	1,022,229	976,366
Fair Value	1,023,718	973,864
Unrealized Appreciation/ (Depreciation)	1,489	(2,502)
Unitranche First Lien Last Out
Summary Of Investment Holdings [Line Items]
Cost	5,660	15,627
Fair Value	5,846	13,544
Unrealized Appreciation/ (Depreciation)	186	(2,083)
Senior Secured Second Lien
Summary Of Investment Holdings [Line Items]
Cost	47,010	62,659
Fair Value	41,814	58,212
Unrealized Appreciation/ (Depreciation)	(5,196)	(4,447)
Unsecured Debt One
Summary Of Investment Holdings [Line Items]
Cost	17,149	3,915
Fair Value	18,686	4,061
Unrealized Appreciation/ (Depreciation)	1,537	146
Equity & Other
Summary Of Investment Holdings [Line Items]
Cost	44,323	40,165
Fair Value	59,222	50,050
Unrealized Appreciation/ (Depreciation)	14,899	9,885
LLC/LP Equity Interests
Summary Of Investment Holdings [Line Items]
Cost	50,600	57,707
Fair Value	40,479	53,134
Unrealized Appreciation/ (Depreciation)	$ (10,121)	$ (4,573)