Loans Payable and Long-Term Debt (Schedule Of Debt Maturities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2025	Apr. 30, 2024	Mar. 08, 2022
Debt Instrument [Line Items]
2026	$ 7,659
2027	9,616
2028	13,401
2029	17,820
2030	328,491
2031 AND THERE-AFTER	0
Debt, outstanding balance	376,987	$ 376,114
Debt issuance costs	(3,503)	(1,631)
Current maturities	(7,659)	(2,722)
Total long-term debt	365,825	371,761
Outstanding amounts under finance lease obligations	$ 6,080
Minimum [Member]
Debt Instrument [Line Items]
Interest rates on finance leases (percent)	2.90%
Maximum [Member]
Debt Instrument [Line Items]
Interest rates on finance leases (percent)	6.90%
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Loan agreement amount			$ 400
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Borrowed under the Credit Agreement	$ 173,400	163,800
Line of Credit Facility, Commitment Fee Percentage	0.20%
Consolidated Interest Coverage Ratio	2.00
Total Net Leverage Ratio	4.00
Letter of Credit [Member]
Debt Instrument [Line Items]
Borrowed under the Credit Agreement	$ 12,400	13,300
Term Loans [Member]
Debt Instrument [Line Items]
2026	5,000
2027	7,500
2028	12,500
2029	17,500
2030	155,000
2031 AND THERE-AFTER	0
Debt, outstanding balance	197,500	206,250
Economic Development Loans [Member]
Debt Instrument [Line Items]
2026	2,659
2027	2,116
2028	901
2029	320
2030	84
2031 AND THERE-AFTER	0
Debt, outstanding balance	6,080	5,684
Other Long-term Debt [Member]
Debt Instrument [Line Items]
2026	0
2027	0
2028	0
2029	0
2030	0
2031 AND THERE-AFTER	0
Debt, outstanding balance	0	430
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
2026	0
2027	0
2028	0
2029	0
2030	173,407
2031 AND THERE-AFTER	0
Debt, outstanding balance	$ 173,407	$ 163,750