Quarterly report [Sections 13 or 15(d)]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)

v3.25.4
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)
$ in Thousands
 9 Months Ended
Dec. 31, 2025
USD ($)
segment
Mar. 31, 2025
USD ($)
Summary of Investment Holdings [Line Items]    
Investments, cost $ 1,058,898 $ 939,066 [1]
Investments at fair value $ 1,222,792 979,320 [1]
Number of reportable segments | segment 1  
B+T Group Acquisition, Inc. ("B+T"), Diligent Delivery Systems ("Diligent") and Edge Adhesives Holdings, Inc. ("Edge")    
Summary of Investment Holdings [Line Items]    
Investments, cost $ 40,300  
Cost percentage 5.40%  
Investments at fair value $ 18,900  
Fair value percentage 2.70%  
B+T, Diligent, Edge and J.R. Hobbs Co. – Atlanta, LLC (“J.R. Hobbs”)    
Summary of Investment Holdings [Line Items]    
Investments, cost   $ 90,200
Cost percentage   13.10%
Investments at fair value   $ 50,900
Fair value percentage   8.20%
[1] Cumulative gross unrealized appreciation for federal income tax purposes is $183.3 million; cumulative gross unrealized depreciation for federal income tax purposes is $144.9 million. Cumulative net unrealized appreciation is $38.5 million, based on a tax cost of $940.9 million.