Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%	21.00%
Federal income tax credits	5.40%	(1.20%)	(0.90%)
Stock compensation	(0.30%)	0.20%	(0.10%)
Uncertain tax positions	1.70%	0.00%	0.00%
Meals and entertainment	(0.40%)	0.10%	0.30%
Valuation allowance for deferred taxes	0.00%	0.00%	0.70%
Foreign	0.60%	0.60%	0.40%
Other	(0.60%)	0.20%	0.70%
State income taxes, net of federal tax effect	3.40%	3.20%	3.40%
Effective income tax rate	30.80%	24.10%	25.50%