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INVESTMENTS - Schedule of Investments by Security Type at Fair Value and Investments Valued Using Level 3 Inputs (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Mar. 31, 2024
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | $ 853,307 | $ 920,504
Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 18
Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 853,307 | 920,486
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 853,307 | 920,486
Significant Unobservable Inputs (Level 3) | Non-Control/Non-Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 627,240 | 622,215
Significant Unobservable Inputs (Level 3) | Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 225,497 | 295,366
Significant Unobservable Inputs (Level 3) | Control Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 570 | 2,905
Secured first lien debt |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 469,480 | 474,856
Secured first lien debt | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Secured first lien debt | Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Secured first lien debt | Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 469,480 | 474,856
Secured first lien debt | Significant Unobservable Inputs (Level 3) | Non-Control/Non-Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 322,601 | 324,348
Secured first lien debt | Significant Unobservable Inputs (Level 3) | Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 146,309 | 147,603
Secured first lien debt | Significant Unobservable Inputs (Level 3) | Control Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 570 | 2,905
Secured second lien debt |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 111,344 | 138,703
Secured second lien debt | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Secured second lien debt | Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Secured second lien debt | Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 111,344 | 138,703
Secured second lien debt | Significant Unobservable Inputs (Level 3) | Non-Control/Non-Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 92,748 | 93,340
Secured second lien debt | Significant Unobservable Inputs (Level 3) | Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 18,596 | 45,363
Secured second lien debt | Significant Unobservable Inputs (Level 3) | Control Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Preferred equity |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 228,528 | 213,480
Preferred equity | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Preferred equity | Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Preferred equity | Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 228,528 | 213,480
Preferred equity | Significant Unobservable Inputs (Level 3) | Non-Control/Non-Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 167,936 | 162,522
Preferred equity | Significant Unobservable Inputs (Level 3) | Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 60,592 | 50,958
Preferred equity | Significant Unobservable Inputs (Level 3) | Control Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Common equity/equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 43,955 | 93,465
Common equity/equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 0
Common equity/equivalents | Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 18
Common equity/equivalents | Significant Other Observable Inputs (Level 2) | Funko Acquisition Holdings, LLC |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value |  | 18
Common equity/equivalents | Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 43,955 | 93,447
Common equity/equivalents | Significant Unobservable Inputs (Level 3) | Non-Control/Non-Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 43,955 | 42,005
Common equity/equivalents | Significant Unobservable Inputs (Level 3) | Affiliate Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | 0 | 51,442
Common equity/equivalents | Significant Unobservable Inputs (Level 3) | Control Investments | Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments at fair value | $ 0 | $ 0

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