Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2024	Jul. 31, 2023	Apr. 30, 2024
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 641,999		$ 653,724
Less accumulated amortization and depreciation	(389,633)		(381,263)
Property, plant and equipment, net	252,366		272,461
Amortization and depreciation expense on property, plant and equipment	11,200	$ 9,600
Finance lease, right-of-use asset, accumulated amortization	31,400		31,700
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	4,475		4,475
Buildings and improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	134,487		131,663
Buildings and improvements - finance leases
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	11,164		11,164
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	389,870		370,940
Machinery and equipment - finance leases
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	32,204		32,173
Software
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	31,143		39,252
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 38,656		$ 64,057