Restructuring - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	$ (127)	$ (847)	$ 183	$ 5,404
Facility Closing | Discontinued Operations, Disposed of by Sale | Humboldt Facility
Restructuring Cost and Reserve [Line Items]
Gain on disposition of business		2,300
Manufacturing Plant Closure
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	0	(700)	300	3,900
Employee Severance | Nationwide Reductions In Force
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	$ (100)	$ (100)	$ (100)	$ 1,500