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FAIR VALUE HIERARCHY FOR INVESTMENTS—PORTFOLIO COMPOSITION - Schedule of Investments at Fair Value Hierarchy (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Dec. 31, 2024
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Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | $ 1,260,853 | [1] | $ 1,177,507 | [2]
Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Significant Other Observable Inputs (Level 2) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Significant Unobservable Inputs (Level 3) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 1,260,853 |  | 1,177,507 |
Private Loan portfolio investments |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 767,780 |  | 677,878 |
Private Loan portfolio investments | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Private Loan portfolio investments | Significant Other Observable Inputs (Level 2) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Private Loan portfolio investments | Significant Unobservable Inputs (Level 3) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 767,780 |  | 677,878 |
LMM portfolio investments |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 439,689 |  | 436,150 |
LMM portfolio investments | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
LMM portfolio investments | Significant Other Observable Inputs (Level 2) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
LMM portfolio investments | Significant Unobservable Inputs (Level 3) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 439,689 |  | 436,150 |
Middle Market portfolio investments |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 30,781 |  | 39,402 |
Middle Market portfolio investments | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Middle Market portfolio investments | Significant Other Observable Inputs (Level 2) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Middle Market portfolio investments | Significant Unobservable Inputs (Level 3) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 30,781 |  | 39,402 |
Other Portfolio investments |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 22,603 |  | 24,077 |
Other Portfolio investments | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Other Portfolio investments | Significant Other Observable Inputs (Level 2) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | 0 |  | 0 |
Other Portfolio investments | Significant Unobservable Inputs (Level 3) |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investments at fair value: | $ 22,603 |  | $ 24,077 |
[1] | Investment fair value was determined using significant unobservable inputs, unless otherwise noted. See Note C — Fair Value Hierarchy for Investments — Portfolio Composition for further discussion. Negative fair value is the result of the capitalized discount on the loan or the unfunded commitment being valued below par.
[2] | Investment fair value was determined using significant unobservable inputs, unless otherwise noted. See Note C — Fair Value Hierarchy for Investments — Portfolio Composition for further discussion. Negative fair value is the result of the capitalized discount on the loan or the unfunded commitment being valued below par.

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