Deferred Compensation and Retirement Plans - Reconciliation of Benefit Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Change in benefit obligation:
Current liability	$ 43,377	$ 27,219
Non-current benefit obligation	440,396	396,534
Total liability	483,773	423,753
Medical And Life Insurance Benefits \| Hay Group
Change in benefit obligation:
Balance, beginning of year	4,838	5,365
Interest cost	217	195	$ 110
Actuarial gain	(321)	(93)
Benefits paid from cash	(507)	(629)
Balance, end of year	4,227	4,838	$ 5,365
Current liability	535	563
Non-current benefit obligation	3,692	4,275
Total liability	$ 4,227	$ 4,838

Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

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Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as current.

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Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans.

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