v3.25.1
Note 10 - Stockholders' Equity (Details Textual) - USD ($)
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Dividends, Preferred Stock, Cash $ 23,181 $ 23,000 $ 23,000
Common Stock, Capital Shares Reserved for Future Issuance 33,695 33,695  
Treasury Stock, Value, Acquired, Cost Method $ 11,591,000 $ 33,030,000 $ 41,209,000
Treasury Stock, Shares, Acquired 5,305,301    
Treasury Stock, Value $ 210,669,000 200,107,000  
Defined Contribution Plan, Employer Discretionary Contribution Share Amount 34,487    
Defined Contribution Plan, Employer Discretionary Contribution Value of Shares $ 1,000,000    
Series A Preferred Stock [Member]      
Preferred Stock, Shares Authorized 8,200,000    
Preferred Stock, Par or Stated Value Per Share (in dollars per share) $ 0.025    
Preferred Stock, Dividend Rate, Percentage 10.00%    
Preferred Stock, Stated Value Per Share (in dollars per share) $ 0.25    
Dividends, Preferred Stock, Cash $ 10,181 10,181  
Preferred Stock, Shares Non-designated 6,792,109    
Cumulative Convertible Preferred Stock, Series A, 10 Percent [Member]      
Preferred Stock, Shares Authorized 1,000,000    
Preferred Stock, Dividend Rate, Percentage 10.00%    
Preferred Stock, Shares Outstanding (in shares) 407,240    
Convertible from Series A Preferred Stock to Class A Stock [Member]      
Share for Share Conversion Number (in shares) 20    
Series B Preferred Stock [Member]      
Preferred Stock, Shares Authorized 400,000    
Preferred Stock, Par or Stated Value Per Share (in dollars per share) $ 0.025    
Preferred Stock, Dividend Rate, Percentage 10.00%    
Preferred Stock, Shares Outstanding (in shares) 400,000    
Preferred Stock, Stated Value Per Share (in dollars per share) $ 0.25    
Dividends, Preferred Stock, Cash $ 10,000 $ 10,000  
Convertible from Series B Preferred Stock to Class A Stock [Member      
Share for Share Conversion Number (in shares) 30    
Convertible Preferred Stock [Member]      
Preferred Stock, Shares Outstanding (in shares) 7,891    
Convertible Preferred Stock, Shares Issued upon Conversion 1    
Preferred Stock, Dividends Per Share, Declared (in dollars per share) $ 0 $ 0  
Preferred Stock, Liquidation Preference Per Share $ 12    
Conversion of Stock, Shares Converted (in shares) 401    
Cumulative Preferred Stock [Member]      
Preferred Stock, Shares Authorized 200,000    
Preferred Stock, Par or Stated Value Per Share (in dollars per share) $ 0.25    
Preferred Stock, Dividend Rate, Percentage 6.00%    
Preferred Stock, Shares Outstanding (in shares) 200,000 200,000 200,000
Dividends, Preferred Stock, Cash $ 3,000 $ 3,000  
Preferred Stock, Dividends, Per Share, Cash Paid $ 0.015    
No Par Value Preferred Stock [Member]      
Preferred Stock, Shares Authorized 30,000    
Preferred Stock, Shares Outstanding (in shares) 0    
Common Class A [Member]      
Voting Rights, Percentage of Vote Per Share 0.05%    
Stock Issued During Period, Shares, Employee Stock Ownership Plan 3,870    
Common Stock, Capital Shares Reserved for Future Issuance 7,891 8,292  
Treasury Stock, Value, Acquired, Cost Method $ 11,600,000    
Treasury Stock, Shares, Acquired 194,370    
Common Class B [Member]      
Stock Issued During Period, Profit Sharing Bonus Plan (in shares) 108    
Treasury Stock, Shares, Acquired 0