Defined Benefit Pension Plans - Pension Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2022	Jul. 31, 2021
Retirement Benefits [Abstract]
Service cost	$ 0	$ 0
Interest cost	322	177
Expected return on plan assets	(535)	(401)
Recognition of net loss	240	135
Net periodic pension expense (income)	$ 27	$ (89)