Note 5 - Accounts Receivable, Net, Contract Asset and Contract Liability (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2024	Jul. 31, 2023	Apr. 30, 2024
Accounts Receivable, after Allowance for Credit Loss	$ 7,326		$ 5,776
Accounts Receivable, Allowance for Credit Loss	47		47
Contract with Customer, Asset, after Allowance for Credit Loss	2,376		$ 3,812
Increase (Decrease) in Contract with Customer, Asset	(1,436)	$ 1,276
Increase (Decrease) in Contract with Customer, Liability	$ 2,116	$ 3,225