Deferred Compensation and Retirement Plans - Reconciliation of Fair Value of Plan Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Change in benefit obligation:
Current liability	$ 27,219	$ 18,916
Non-current liability	396,534	357,175
Total liability	423,753	376,091
Medical and Life Insurance \| Hay Group
Change in benefit obligation:
Balance, beginning of year	5,365	6,584
Interest cost	195	110	$ 140
Actuarial gain	(93)	(857)
Benefits paid from cash	(629)	(472)
Balance, end of year	4,838	5,365	$ 6,584
Current liability	563	585
Non-current liability	4,275	4,780
Total liability	$ 4,838	$ 5,365

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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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

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