FAIR VALUE MEASUREMENTS - Schedule of Fair Value Measurements of Investments, by Major Class, and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2025		Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	$ 2,009,911	[1]	$ 2,122,221	[2]
Derivative asset	11,057		0
Total	2,020,968
First-Lien Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	1,768,014		1,885,643
Subordinated Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	158,927		159,138
Equity Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	40,941		36,598
Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	42,029		40,842
Subordinated Debt, Second Lien
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	72,488		67,780
Subordinated Debt, Mezzanine Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	83,950		89,740
Structured Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	2,489		1,618
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	42,029		40,842
Derivative asset	0
Total	42,029
Level 1 | First-Lien Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0		0
Level 1 | Subordinated Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0		0
Level 1 | Equity Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0		0
Level 1 | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	42,029		40,842
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	14,104		87,152
Derivative asset	11,057
Total	25,161
Level 2 | First-Lien Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	7,955		78,793
Level 2 | Subordinated Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	6,149		8,359
Level 2 | Equity Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0		0
Level 2 | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0		0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	1,947,254		1,994,227
Derivative asset	0
Total	1,947,254
Level 3 | First-Lien Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	1,760,059		1,806,850
Level 3 | Subordinated Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	152,778		150,779
Level 3 | Equity Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	34,417		36,598
Level 3 | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0		$ 0
Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	6,524
Derivative asset	0
Total	6,524
Measured at NAV | First-Lien Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0
Measured at NAV | Subordinated Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	0
Measured at NAV | Equity Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	6,524
Measured at NAV | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments and cash equivalents	$ 0

[1] Investment valued using unobservable inputs (Level 3), unless noted otherwise. See Note 2 “Significant Accounting Policies – Valuation of Portfolio Investments” and Note 5 "Fair Value Measurements" for more information.

[2] Investment valued using unobservable inputs (Level 3). See Note 2 “Significant Accounting Policies – Valuation of Portfolio Investments” and Note 5 "Fair Value Measurements" for more information.