Note 4 - Investments - Income From Securities Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Dividend income	$ 551	$ 595	$ 851
Interest income	1,934	706	18
Investment gains/(losses) recognized on sales of equity securities during the period	(1)	(81)	(1,568)
Unrealized gains/(losses) recognized on equity securities held at the end of the period	288	(45)	167
Other	(8)	(1)	(2)
Total investment gains/(losses)	$ 2,764	$ 1,174	$ (534)