Annual report pursuant to Section 13 and 15(d)

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

v3.23.3
INVESTMENTS - Fair Value Measurement Inputs and Valuation Techniques (Details)
$ in Thousands
Sep. 30, 2023
USD ($)
Sep. 30, 2022
USD ($)
investment
Sep. 30, 2021
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 704,815 [1] $ 649,615 [2]  
Leeds Acquisition Holdings, LLC      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value   200 $ 6,400
Funko Acquisition Holdings, LLC      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value   22 $ 58
Significant Unobservable Inputs (Level 3)      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 704,562 643,160  
Significant Unobservable Inputs (Level 3) | Measurement Input, Expected Payoff Amount | Secured first lien debt      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value   $ 18,800  
Investment owned, number of investments | investment   1  
Significant Unobservable Inputs (Level 3) | Measurement Input, Expected Payoff Amount | Preferred and common equity / equivalents      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value   $ 8,000  
Investment owned, number of investments | investment   1  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Secured first lien debt      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 461,638 $ 423,912  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Secured second lien debt      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 110,820 $ 97,472  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured first lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.118 0.080  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured first lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.299 0.295  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured first lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.148 0.118  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured second lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.125 0.115  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured second lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.156 0.154  
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured second lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.145 0.138  
Significant Unobservable Inputs (Level 3) | TEV | Secured first lien debt      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 49,063 $ 39,946  
Significant Unobservable Inputs (Level 3) | TEV | Secured second lien debt      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 7,425 7,665  
Significant Unobservable Inputs (Level 3) | TEV | Unsecured debt      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 24 55  
Significant Unobservable Inputs (Level 3) | TEV | Preferred and common equity / equivalents      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 65,983 $ 63,319  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured first lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 4.7 4.8  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured first lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 6.8 6.7  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured first lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 6.7 6.2  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured second lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 5.6 5.6  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured second lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 5.6 5.6  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Secured second lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 5.6 5.6  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Preferred and common equity / equivalents | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 4.7 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]      
Fair value, measurement input 13.0 11.0  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA multiple | Preferred and common equity / equivalents | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 6.9 6.5  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured first lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 995 $ 800  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured first lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 14,002 10,257  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured first lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 13,624 7,605  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured second lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 3,690 3,299  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured second lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 3,690 3,299  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Secured second lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 3,690 3,299  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Preferred and common equity / equivalents | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 995 800  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Preferred and common equity / equivalents | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 112,841 74,512  
Significant Unobservable Inputs (Level 3) | TEV | EBITDA | Preferred and common equity / equivalents | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 10,570 $ 11,742  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Secured first lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.3 0.3  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Secured first lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.8 0.6  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Secured first lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.6 0.5  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Unsecured debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 1.0 0.3  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Unsecured debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 1.0 1.3  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Unsecured debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 1.0 1.0  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Preferred and common equity / equivalents | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.3 0.3  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Preferred and common equity / equivalents | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 3.0 4.4  
Significant Unobservable Inputs (Level 3) | TEV | Revenue multiple | Preferred and common equity / equivalents | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 1.2 1.4  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Secured first lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 14,934 $ 11,514  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Secured first lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 16,283 16,320  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Secured first lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 15,361 14,656  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Unsecured debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 5,044 764  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Unsecured debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 5,044 11,514  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Unsecured debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 5,044 4,249  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Preferred and common equity / equivalents | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 4,213 764  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Preferred and common equity / equivalents | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 16,283 42,926  
Significant Unobservable Inputs (Level 3) | TEV | Revenue | Preferred and common equity / equivalents | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value 14,959 19,963  
Significant Unobservable Inputs (Level 3) | Market Quote | Secured second lien debt      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Investments, at fair value $ 9,609 $ 10,791  
Significant Unobservable Inputs (Level 3) | Market Quote | IBP | Secured second lien debt | Minimum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.678 0.820  
Significant Unobservable Inputs (Level 3) | Market Quote | IBP | Secured second lien debt | Maximum      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.940 0.950  
Significant Unobservable Inputs (Level 3) | Market Quote | IBP | Secured second lien debt | Weighted Average      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair value, measurement input 0.822 0.865  
[1] Cumulative gross unrealized depreciation for federal income tax purposes is $56.9 million; cumulative gross unrealized appreciation for federal income tax purposes is $33.7 million. Cumulative net unrealized depreciation is $23.2 million, based on a tax cost of $728.0 million.
[2] Cumulative gross unrealized depreciation for federal income tax purposes is $52.3 million; cumulative gross unrealized appreciation for federal income tax purposes is $35.2 million. Cumulative net unrealized depreciation is $17.1 million, based on a tax cost of $666.7 million.