Note 8 - Federal, State and Local Income Taxes - Effective Income Tax Rate Reconciliation (Details)	3 Months Ended		12 Months Ended
	Jul. 31, 2024	Jul. 31, 2023	Apr. 30, 2019
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	3.69%	3.10%
Effect of dividends received deductions	(0.19%)	(0.24%)
Other, net	0.00%	0.01%
Effective income tax rate	24.50%	23.87%