v3.26.1
Note 4 - Investments (Details Textual) - USD ($)
 9 Months Ended 12 Months Ended
Jan. 31, 2026
Jan. 31, 2025
Apr. 30, 2026
Apr. 30, 2025
Apr. 30, 2024
Equity Securities, FV-NI, Cost     $ 17,142,000 $ 15,513,000  
Equity securities     25,603,000 20,879,000  
Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent     (38,000) 187,000 $ (627,000)
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax     (11,000) 50,000 (166,000)
Proceeds from Sale of Equity Securities, FV-NI     2,425,000 3,243,000 $ 1,129,000
Equity Securities, FV-NI, Gain (Loss) $ 599,000 $ (126,000)      
Equity Securities, FV-NI, Gain (Loss) $ 599,000 $ (126,000)      
Equity Method Investments     60,217,000 60,807,000  
EAM Trust [Member]          
Fair Value of Contributed Capital at Inception     55,805,000 55,805,000  
Cash and Liquid Securities in Excess of Working Capital Requirements Contributed to Capital Account     5,820,000 5,820,000  
Equity Method Investment, Other-than-Temporary Impairment     $ 0 0  
Percentage of Non Voting Profit Interest     50.00%    
Accrued Non Voting Revenues and Non Voting Profits Interests Payable     $ 3,885,000 4,493,000  
Fixed Income Securities [Member]          
Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale     15,311,000 43,477,000  
AOCI, Debt Securities, Available-for-Sale, Adjustment, after Tax     131,000 83,000  
Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent     (49,000) (237,000)  
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax     $ (10,000) $ (50,000)  
Debt Securities, Available-for-Sale, Weighted Average Yield     3.59% 5.99%  
Fixed Income Securities [Member] | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]          
AOCI Tax, Attributable to Parent     $ 28,000 $ 17,000