v3.26.1
Borrowings - Narrative (Details)
 3 Months Ended 9 Months Ended
Mar. 29, 2027
Mar. 28, 2027
Jun. 30, 2026
USD ($)
portfolioCompany
Nov. 26, 2025
Nov. 25, 2025
Jun. 20, 2025
USD ($)
Jun. 13, 2025
Jun. 12, 2025
May 31, 2025
Aug. 15, 2024
Mar. 28, 2024
Jun. 30, 2026
USD ($)
portfolioCompany
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
portfolioCompany
Jun. 30, 2025
USD ($)
Sep. 30, 2025
USD ($)
portfolioCompany
Jun. 03, 2025
USD ($)
Jun. 02, 2025
USD ($)
Apr. 02, 2022
Debt Instrument [Line Items]                                      
Minimum asset coverage ratio required (in percent)                                     1.50
Asset coverage ratio (in percent)     181.22%                 181.22% 182.58% 181.22% 182.58%        
Fair Value     $ 2,667,489,000 [1]                 $ 2,667,489,000 [1]   $ 2,667,489,000 [1]   $ 2,209,174,000 [2]      
Amount Outstanding     $ 1,491,565,000                 1,491,565,000   1,491,565,000   $ 1,181,274,000      
Short-term debt, average outstanding amount                       $ 1,397,735,000 $ 950,894,000 $ 1,344,035,000 $ 861,741,000        
Annualized average stated interest rate                       5.80% 6.90% 5.80% 7.10%        
2025 Debt Securitization                                      
Debt Instrument [Line Items]                                      
Debt instrument, face amount           $ 1,154,900,000                          
Number of investment portfolio company | portfolioCompany     123                 123   123   126      
Fair Value     $ 1,125,962,000                 $ 1,125,962,000   $ 1,125,962,000   $ 1,139,381,000      
Annualized average stated interest rate                       5.40% 6.10% 5.50% 6.10%        
2025 Debt Securitization | Subordinated debt                                      
Debt Instrument [Line Items]                                      
Debt instrument, face amount           286,650,000                          
2025 Debt Securitization | Class A-1 2025 Notes                                      
Debt Instrument [Line Items]                                      
Debt instrument, face amount           $ 667,000,000                          
Interest Rate     1.63%     1.63%                          
Amount Outstanding     $ 667,000,000                 $ 667,000,000   $ 667,000,000          
2025 Debt Securitization | Class A-2 2025 Notes                                      
Debt Instrument [Line Items]                                      
Debt instrument, face amount           $ 40,250,000                          
Interest Rate     1.80%     1.80%                          
Amount Outstanding     $ 40,250,000                 40,250,000   40,250,000          
2025 Debt Securitization | Class B 2025 Notes                                      
Debt Instrument [Line Items]                                      
Debt instrument, face amount           $ 92,000,000                          
Interest Rate     2.00%     2.00%                          
Amount Outstanding     $ 92,000,000                 $ 92,000,000   $ 92,000,000          
2025 Debt Securitization | Class C Notes                                      
Debt Instrument [Line Items]                                      
Debt instrument, face amount           $ 69,000,000                          
Interest Rate           2.80%                          
PNC Facility                                      
Debt Instrument [Line Items]                                      
Annualized average stated interest rate                         6.50%   6.70%        
PNC Facility | Line of Credit | Revolving Credit Facility                                      
Debt Instrument [Line Items]                                      
Line of credit facility, maximum borrowing capacity                                 $ 100,000,000 $ 250,000,000  
PNC Facility | Line of Credit | Revolving Credit Facility | Minimum                                      
Debt Instrument [Line Items]                                      
Interest Rate                 2.15%                    
PNC Facility | Line of Credit | Revolving Credit Facility | Maximum                                      
Debt Instrument [Line Items]                                      
Interest Rate                 2.45%                    
DB Credit Facility                                      
Debt Instrument [Line Items]                                      
Annualized average stated interest rate                       5.10% 6.40% 5.30% 6.70%        
DB Credit Facility | Sterling Overnight Index Average                                      
Debt Instrument [Line Items]                                      
Debt instrument, credit spread adjustment (in percent)                     0.1193%                
DB Credit Facility | Line of Credit | Revolving Credit Facility                                      
Debt Instrument [Line Items]                                      
Interest Rate             1.75% 2.35%                      
Line of credit facility, maximum borrowing capacity     300,000,000                 $ 300,000,000   $ 300,000,000          
Debt instrument, term (in years)                     3 years                
Line of credit facility, non-usage fee, (in percent)                     0.25%                
Line of credit facility, prepayment fee, year one, (in percent)                     0.50%                
Line of credit facility, prepayment fee, year two, (in percent)                     0.25%                
Amount Outstanding     $ 195,595,000                 $ 195,595,000   $ 195,595,000   198,117,000      
DB Credit Facility | Line of Credit | Revolving Credit Facility | Base Rate                                      
Debt Instrument [Line Items]                                      
Interest Rate     1.75%                                
DB Credit Facility | Line of Credit | Revolving Credit Facility | Canadian Overnight Repo Rate Average                                      
Debt Instrument [Line Items]                                      
Interest Rate                     0.32138%                
DB Credit Facility | Line of Credit | Revolving Credit Facility | Forecast                                      
Debt Instrument [Line Items]                                      
Interest Rate 2.25% 2.85%                                  
DB Credit Facility | Line of Credit | Revolving Credit Facility | Forecast | Base Rate                                      
Debt Instrument [Line Items]                                      
Interest Rate 2.25%                                    
BNP Credit Facility                                      
Debt Instrument [Line Items]                                      
Annualized average stated interest rate                       5.30% 6.30% 5.30% 6.40%        
BNP Credit Facility | Line of Credit | Revolving Credit Facility                                      
Debt Instrument [Line Items]                                      
Interest Rate     2.10%                                
Line of credit facility, maximum borrowing capacity     $ 750,000,000                 $ 750,000,000   $ 750,000,000          
Debt instrument, term (in years)                   36 months                  
Amount Outstanding     $ 502,084,000                 $ 502,084,000   $ 502,084,000   192,188,000      
BNP Credit Facility | Line of Credit | Revolving Credit Facility | Base Rate                                      
Debt Instrument [Line Items]                                      
Interest Rate     1.85%                                
BNP Credit Facility | Line of Credit | Revolving Credit Facility | Debt Variable Rate One                                      
Debt Instrument [Line Items]                                      
Interest Rate       1.85% 2.10%                            
BNP Credit Facility | Line of Credit | Revolving Credit Facility | Debt Variable Rate Two                                      
Debt Instrument [Line Items]                                      
Interest Rate       2.10% 2.35%                            
Adviser Revolver                                      
Debt Instrument [Line Items]                                      
Annualized average stated interest rate                         4.10%   4.10%        
Adviser Revolver | Revolving Credit Facility | Short-term Applicable Federal Rate                                      
Debt Instrument [Line Items]                                      
Debt instrument, interest rate, stated percentage     3.80%                 3.80%   3.80%          
Adviser Revolver | Line of Credit | Revolving Credit Facility                                      
Debt Instrument [Line Items]                                      
Line of credit facility, maximum borrowing capacity     $ 100,000,000                 $ 100,000,000   $ 100,000,000   100,000,000      
Amount Outstanding     $ 0                 $ 0   $ 0   $ 0      
[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.