v3.26.1
Fair Value of Financial Instruments - Summary of Unobservable Inputs and Ranges (Details) - Level 3
$ in Thousands
Jun. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 867,333 $ 1,087,964
Truist Credit Facility | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 309,755 $ 425,477
Range of Input 0.057 [1] 0.049 [2]
Equity | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 218,799 $ 286,210
Minimum | Equity | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.005 [1] 0.015 [2]
Maximum | Equity | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.178 [1] 0.283 [2]
Weighted Average | Equity | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.097 [1] 0.094 [2]
First Lien | Market Comparable | Broker/Dealer Bids or Quotes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 27,772 $ 31,018
First Lien | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value 369,585 550,259
First Lien | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 27,190 $ 1,096
First Lien | Minimum | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.07 [1] 0.04 [2]
First Lien | Minimum | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.007 [1] 0.075 [2]
First Lien | Maximum | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.216 [1] 0.245 [2]
First Lien | Maximum | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.178 [1] 0.083 [2]
First Lien | Weighted Average | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.098 [1] 0.101 [2]
First Lien | Weighted Average | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.093 [1] 0.081 [2]
Second Lien | Market Comparable | Broker/Dealer Bids or Quotes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value   $ 3,411
Second Lien | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 14,806 $ 14,750
Second Lien | Minimum | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.138 [1] 0.132 [2]
Second Lien | Maximum | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.165 [1] 0.155 [2]
Second Lien | Weighted Average | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.15 [1] 0.143 [2]
Subordinated Debt / Corporate Notes | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 184,546 $ 201,220
Subordinated Debt / Corporate Notes | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Fair value $ 24,635  
Subordinated Debt / Corporate Notes | Minimum | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.117 [1] 0.07 [2]
Subordinated Debt / Corporate Notes | Minimum | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input [1] 0.009  
Subordinated Debt / Corporate Notes | Maximum | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.161 [1] 0.254 [2]
Subordinated Debt / Corporate Notes | Maximum | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input [1] 0.303  
Subordinated Debt / Corporate Notes | Weighted Average | Market Comparable | Market Yield    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input 0.125 [1] 0.132 [2]
Subordinated Debt / Corporate Notes | Weighted Average | Enterprise Market Value | EBITDA Multiple    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Range of Input [1] 0.054  
[1] The weighted averages disclosed in the table above were weighted by their relative fair value.
[2] The weighted averages disclosed in the table above were weighted by their relative fair value.