Note H - Income Taxes - Reconciliation of Income Tax to Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Statement [Line Items]
Tax provision at statutory rate	$ 5,417	$ 25,753	$ 28,420
State taxes, net of federal benefit	774	3,679	4,060
Tax benefit from option exercises	(558)	(1,356)	(1,401)
Other, net	(271)	(455)	(567)
Total	$ 5,362	$ 27,621	$ 30,512