v3.26.1
Note D - Marketable Equity Securities (Details Textual) - USD ($)
3 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2025
Investment Income, Dividend $ 240,000 $ 392,000  
Equity Securities, FV-NI, Unrealized Gain (Loss) 1,810,000 $ 1,058,000  
Margin Account Borrowings [Member]      
Short-Term Debt $ 0   $ 0