INVESTMENTS - Schedules of Portfolio Composition by Geographic Composition of Investments at Cost and Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Schedule of Investments [Line Items]
Cost	$ 1,999,126	$ 2,098,575
Fair Value	$ 1,967,882	$ 2,081,379
Fair Value as % of Net Assets	223.25%	214.51%
Investment Owned at Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	100.00%	100.00%
United States
Schedule of Investments [Line Items]
Cost	$ 1,915,109	$ 2,019,779
Fair Value	$ 1,884,073	$ 2,002,726
Fair Value as % of Net Assets	213.74%	206.40%
United States | Investment Owned at Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	95.74%	96.22%
Canada
Schedule of Investments [Line Items]
Cost	$ 43,288	$ 43,489
Fair Value	$ 43,264	$ 43,526
Fair Value as % of Net Assets	4.91%	4.49%
Canada | Investment Owned at Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	2.20%	2.09%
Germany
Schedule of Investments [Line Items]
Cost	$ 27,590	$ 22,142
Fair Value	$ 27,669	$ 22,102
Fair Value as % of Net Assets	3.14%	2.28%
Germany | Investment Owned at Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	1.41%	1.06%
United Kingdom
Schedule of Investments [Line Items]
Cost	$ 13,139	$ 13,165
Fair Value	$ 12,876	$ 13,025
Fair Value as % of Net Assets	1.46%	1.34%
United Kingdom | Investment Owned at Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	0.65%	0.63%