v3.26.1
Significant Accounting Policies and Recent Accounting Updates (Details)
 12 Months Ended
Sep. 30, 2025
USD ($)
segment
Sep. 30, 2024
USD ($)
Sep. 30, 2023
USD ($)
Accounting Policies [Abstract]      
Amortization of deferred loan origination fees, net $ 8,699,000 $ 15,762,000 $ 5,096,000
Interest income, operating, accretion of discounts 5,420,000 3,078,000 641,000
Payment-in-kind interest income 9,552,000 6,256,000 1,634,000
Payment-in-kind interest capitalized 9,486,000 6,286,000 1,629,000
Investment company, premium prepayment fees 532,000 104,000 0
Interest and fee income 158,327,000 80,674,000 17,877,000
Non-cash preferred dividends 628,000 181,000 114,000
Dividend income, operating, paid in kind 628,000 181,000 114,000
Proceeds from dividends received 208,000 0 0
Dividend income received in cash 200,000 0 8,000
Return of capital 600,000 0 0
Investments on non-accrual status 0 0  
Preferred equity securities aggregate amount in nonaccrual status 0 0  
Excise tax 0 25,000 53,000
Deferred debt issuance cost 8,281,000 7,871,000  
Amortization of deferred debt issuance costs $ 4,061,000 1,644,000 327,000
Deferred offering cost, amortization duration 3 years    
Amortization of deferred offering costs $ 68,000 $ 134,000 $ 83,000
Number of operating segments | segment 1    
Number of reportable segments | segment 1