Deferred Compensation and Retirement Plans - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2022	Oct. 31, 2021	Oct. 31, 2022	Oct. 31, 2021	Apr. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Increase in market value of the underlying COLI investments			$ 4,890	$ 2,184
Increase (decrease) in the fair value of marketable securities	$ (9,700)	$ 4,800	(9,700)	10,000
CSV of COLI Contracts
Defined Benefit Plan Disclosure [Line Items]
Increase in market value of the underlying COLI investments	2,900	1,700	4,900	2,200
Deferred Compensation Plan | CSV of COLI Contracts
Defined Benefit Plan Disclosure [Line Items]
Gross CSV	263,400		263,400		$ 263,200
Outstanding policy loans	79,200		$ 79,200		$ 79,800
Executive Capital Accumulation Plan
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation arrangement vesting period			5 years
Compensation expense	(9,500)	4,700	$ (8,600)	10,200
Increase (decrease) in the fair value of marketable securities	$ (9,700)	$ 4,800	$ (9,700)	$ 10,000
Executive Capital Accumulation Plan | Minimum
Defined Benefit Plan Disclosure [Line Items]
Option to receive employee benefits by quarterly installments periods			1 year
Executive Capital Accumulation Plan | Maximum
Defined Benefit Plan Disclosure [Line Items]
Option to receive employee benefits by quarterly installments periods			15 years