Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2025	Apr. 30, 2024	Apr. 30, 2023
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 649,612	$ 653,724
Less accumulated amortization and depreciation	(404,623)	(381,263)
Property, Plant and Equipment, Net, Total	244,989	272,461
Amortization and depreciation expense on property, plant and equipment	50,100	41,200	$ 37,900
Finance Lease, Right-of-Use Asset, Accumulated Amortization	31,500	31,700
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,264	4,475
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	133,251	131,663
Building And Improvements - Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	11,164	11,164
Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	410,287	370,940
Machinery And Equipment - Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	32,434	32,173
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	24,105	64,057
Property, Plant and Equipment, Net, Total	244,989	272,461
Software and Software Development Costs
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 34,107	$ 39,252