Quarterly report [Sections 13 or 15(d)]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)

v3.25.4
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
USD ($)
investment
loan
segment
Dec. 31, 2024
USD ($)
Sep. 30, 2025
USD ($)
loan
investment
Schedule of Investments [Line Items]      
Cost $ 926,040   $ 876,614 [1]
Fair Value 902,912   859,124 [1]
Total interest income (excluding PIK interest income) 21,595 $ 20,557  
PIK interest income $ 2,301 763  
Number of reportable segments | segment 1    
OID      
Schedule of Investments [Line Items]      
Fair Value $ 800   $ 200
Number of loans | loan 3   2
Total interest income (excluding PIK interest income) $ 32 83  
PIK      
Schedule of Investments [Line Items]      
Number of investments | investment 8   9
Proceeds from interest received $ 2,800 $ 4,500  
B+T Group Acquisition, Inc., Edge Adhesives Holdings, Inc,. And WB Xcel Holdings, LLC      
Schedule of Investments [Line Items]      
Cost $ 28,800   $ 28,800
Cost percentage 3.40%   3.60%
Fair Value $ 13,200   $ 13,000
Fair value percentage 1.60%   1.70%
[1] Cumulative gross unrealized depreciation for federal income tax purposes is $59.7 million; cumulative gross unrealized appreciation for federal income tax purposes is $34.1 million. Cumulative net unrealized depreciation is $25.5 million, based on a tax cost of $884.7 million.