Note 5 - Accounts Receivable, Net, Contract Asset and Contract Liability (Details Textual) - USD ($) $ in Thousands	9 Months Ended
	Jan. 31, 2024	Jan. 31, 2023	Apr. 30, 2023
Accounts Receivable, after Allowance for Credit Loss	$ 6,140		$ 3,793
Accounts Receivable, Allowance for Credit Loss	205		205
Contract with Customer, Asset, after Allowance for Credit Loss	2,134		$ 1,893
Increase (Decrease) in Contract with Customer, Asset	241	$ 1,252
Increase (Decrease) in Contract with Customer, Liability	$ (358)	$ 4,043