v3.26.1
Fair Value Measurements - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details)
$ in Thousands
Sep. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 2,209,174 [1] $ 1,311,001 [2]
Level 3 | Senior secured loans    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 77,408 $ 39,358
Level 3 | Senior secured loans | Minimum | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.073 0.085
Level 3 | Senior secured loans | Minimum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 6.0 6.5
Level 3 | Senior secured loans | Maximum | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.090 0.095
Level 3 | Senior secured loans | Maximum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 20.0 16.0
Level 3 | Senior secured loans | Weighted Average | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.083 0.089
Level 3 | Senior secured loans | Weighted Average | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 10.6 8.6
Level 3 | One stop loans | Yield analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 2,043,193 $ 1,215,534
Level 3 | One stop loans | Broker/dealer bids or quotes    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 19,980 34,672
Level 3 | One stop loans | Market comparable companies    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 49  
Level 3 | One stop loans | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 1,758,059 1,027,881
Level 3 | One stop loans | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 285,134 $ 187,653
Level 3 | One stop loans | Minimum | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.038 0.063
Level 3 | One stop loans | Minimum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 8.0 8.0
Level 3 | One stop loans | Minimum | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 2.0 2.8
Level 3 | One stop loans | Maximum | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.205 0.210
Level 3 | One stop loans | Maximum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 33.0 38.0
Level 3 | One stop loans | Maximum | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 15.0 16.5
Level 3 | One stop loans | Weighted Average | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.086 0.093
Level 3 | One stop loans | Weighted Average | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 15.8 16.4
Level 3 | One stop loans | Weighted Average | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 9.1 9.4
Level 3 | Subordinated debt and second lien loans    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 33,463 $ 5,367
Level 3 | Subordinated debt and second lien loans | Market comparable companies    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 66  
Level 3 | Subordinated debt and second lien loans | Minimum | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.098 0.108
Level 3 | Subordinated debt and second lien loans | Minimum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 9.5 9.5
Level 3 | Subordinated debt and second lien loans | Maximum | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.150 0.150
Level 3 | Subordinated debt and second lien loans | Maximum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 24.0 24.0
Level 3 | Subordinated debt and second lien loans | Weighted Average | Market interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.111 0.122
Level 3 | Subordinated debt and second lien loans | Weighted Average | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 17.8 12.3
Level 3 | Equity    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 35,130 $ 16,070
Level 3 | Equity | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 29,941 14,365
Level 3 | Equity | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 5,189 $ 1,705
Level 3 | Equity | Minimum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 8.0 9.0
Level 3 | Equity | Minimum | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 2.0 2.8
Level 3 | Equity | Maximum | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 28.0 23.0
Level 3 | Equity | Maximum | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 15.0 16.5
Level 3 | Equity | Weighted Average | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 17.4 16.6
Level 3 | Equity | Weighted Average | Revenue multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 11.3 15.3
[1] The fair values of investments were valued using significant unobservable inputs, unless otherwise noted. See Note 7. The fair value of loan investments may include the impact of the unfunded commitment being valued below par.
[2] The fair values of investments were valued using significant unobservable inputs, unless otherwise noted. See Note 7. The fair value of loan investments may include the impact of the unfunded commitment being valued below par.