Note 3 - Related Party Transactions - Non-voting Revenues Interest and Non-voting Profits Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Non-voting revenues interest in EAM	$ 11,900	$ 10,397	$ 15,899
Non-voting profits interest in EAM	1,382	734	2,142
Revenues and Profits Distribution from Unconsolidated Entity	$ 13,282	$ 11,131	$ 18,041