Note 13 - Treasury Stock and Repurchase Program (Details Textual) - USD ($)	Apr. 30, 2024	Apr. 30, 2023	Oct. 31, 2022	Oct. 21, 2022	May 31, 2022	Apr. 30, 2022	Mar. 31, 2022	Jul. 31, 2021	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Stock Repurchase Program, Authorized Amount			$ 3,000,000	$ 3,000,000	$ 3,000,000		$ 2,000,000	$ 2,000,000		$ 2,000,000
Share Repurchase Program, Remaining Authorized, Amount	$ 1,211,000	$ 1,266,000				$ 1,241,000			$ 474,000	$ 2,000,000	$ 1,438,000