Note 5 - Accounts Receivable, Net, Contract Asset and Contract Liability (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2024	Oct. 31, 2023	Apr. 30, 2024
Accounts Receivable, after Allowance for Credit Loss	$ 5,402		$ 5,776
Accounts Receivable, Allowance for Credit Loss	47		47
Contract with Customer, Asset, after Allowance for Credit Loss	3,386		$ 3,812
Increase (Decrease) in Contract with Customer, Asset	(426)	$ (138)
Increase (Decrease) in Contract with Customer, Liability	$ 3,077	$ (1,351)