v3.26.3
Note 2 - Investments (Details Textual) - USD ($)
 3 Months Ended 12 Months Ended
Jul. 31, 2026
Jul. 31, 2025
Apr. 30, 2026
Equity Securities, FV-NI, Cost $ 26,449,000   $ 17,142,000
Equity securities 35,564,000   25,603,000
Proceeds from Sale of Equity Securities, FV-NI 45,000 $ 215,000  
Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent 5,000 15,000  
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax 1,000 3,000  
Equity Securities, FV-NI, Gain (Loss) 12,000   (5,000)
Equity Securities, FV-NI, Gain (Loss) 12,000   (5,000)
Equity Method Investments 59,979,000   60,217,000
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 $ 3,827,000   3,885,000
Fixed Income Securities [Member]      
Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale 5,147,000 $ 2,147,000  
AOCI, Debt Securities, Available-for-Sale, Adjustment, after Tax 125,000   131,000
Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent (6,000)   (49,000)
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax $ (1,000)   $ (10,000)
Debt Securities, Available-for-Sale, Weighted Average Yield 3.70%   3.60%
Fixed Income Securities [Member] | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]      
AOCI Tax, Attributable to Parent $ 26,000   $ 28,000