Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021
Loss Contingency [Abstract]
Accrued environmental liability	$ 274	$ 368
Loss Contingencies [Line Items]
Letters of credit outstanding	5,492
Self insurance reserve	53,752	$ 50,526
General Liability and Auto Liability Insurance
Loss Contingencies [Line Items]
Annual stop loss limit	2,000
Workers' Compensation Insurance
Loss Contingencies [Line Items]
Annual stop loss limit	$ 1,000