Quarterly report [Sections 13 or 15(d)]

INVESTMENTS - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details)

v3.25.2
INVESTMENTS - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details)
$ in Thousands
Jun. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 751,260 $ 796,260 [1]
Investments at fair value 751,260 796,260
Secured first lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at fair value 529,149 554,937
Secured second lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at fair value 144,299 113,716
Unsecured debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at fair value 354 32
Significant Unobservable Inputs (Level 3)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 746,214 796,222
Investments at fair value 746,214 796,222
Significant Unobservable Inputs (Level 3) | Secured first lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at fair value 529,149 554,937
Significant Unobservable Inputs (Level 3) | Secured second lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at fair value 144,299 113,716
Significant Unobservable Inputs (Level 3) | Unsecured debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at fair value 354 32
Significant Unobservable Inputs (Level 3) | Yield Analysis | Secured first lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 455,368 464,090
Significant Unobservable Inputs (Level 3) | Yield Analysis | Secured second lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 131,824 $ 101,928
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured first lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.105 0.108
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured first lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.180 0.173
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured first lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.120 0.126
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured second lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.119 0.122
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured second lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.154 0.160
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured second lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.134 0.141
Significant Unobservable Inputs (Level 3) | Market Quote | Secured second lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 3,683 $ 3,241
Significant Unobservable Inputs (Level 3) | Market Quote | IBP | Secured second lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 1.000 0.880
Significant Unobservable Inputs (Level 3) | Market Quote | IBP | Secured second lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 1.000 0.880
Significant Unobservable Inputs (Level 3) | Market Quote | IBP | Secured second lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 1.000 0.880
Significant Unobservable Inputs (Level 3) | TEV | Secured first lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 73,781 $ 90,847
Significant Unobservable Inputs (Level 3) | TEV | Secured second lien debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 8,792 8,547
Significant Unobservable Inputs (Level 3) | TEV | Unsecured debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 354 32
Significant Unobservable Inputs (Level 3) | TEV | Preferred and common equity / equivalents    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 72,412 $ 127,537
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured first lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 4.5 4.1
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured first lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 7.2 13.9
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured first lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 6.3 10
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured second lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 5.4 5.4
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured second lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 5.4 5.4
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured second lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 5.4 5.4
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Unsecured debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 7.2 0
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Unsecured debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 7.2 0
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Unsecured debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 7.2 0
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Preferred and common equity / equivalents | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 4.1 4.1
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Preferred and common equity / equivalents | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 14.7 13.9
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Preferred and common equity / equivalents | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 7.3 8
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured first lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 408 $ 3,020
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured first lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 4,591 16,211
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured first lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 3,330 10,309
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured second lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 2,463 3,343
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured second lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 2,463 3,343
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured second lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 2,463 3,343
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Unsecured debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 4,591 0
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Unsecured debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 4,591 0
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Unsecured debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 4,591 0
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Preferred and common equity / equivalents | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 408 1,182
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Preferred and common equity / equivalents | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 143,118 144,458
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Preferred and common equity / equivalents | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 8,787 $ 10,847
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Secured first lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.6 0.2
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Secured first lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.7 4.6
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Secured first lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.7 2.1
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Unsecured debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 1 1
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Unsecured debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 1 1
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Unsecured debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 1 1
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Preferred and common equity / equivalents | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.6 0.2
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Preferred and common equity / equivalents | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 1 4.6
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Preferred and common equity / equivalents | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment owned, measurement input 0.7 2
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Secured first lien debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 11,320 $ 6,336
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Secured first lien debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 21,248 21,118
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Secured first lien debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 14,719 13,981
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Unsecured debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 5,202 7,834
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Unsecured debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 5,202 7,834
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Unsecured debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 5,202 7,834
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Preferred and common equity / equivalents | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 5,202 4,672
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Preferred and common equity / equivalents | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value 21,248 21,118
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Preferred and common equity / equivalents | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments owned, fair value $ 13,175 $ 12,587
[1] Cumulative gross unrealized depreciation for federal income tax purposes is $66.1 million; cumulative gross unrealized appreciation for federal income tax purposes is $85.8 million. Cumulative net unrealized appreciation is $19.7 million, based on a tax cost of $776.5 million.