Deferred Compensation and Retirement Plans - Changes in ECAP Liability (Detail) - Executive Capital Accumulation Plan - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Balance, beginning of year	$ 166,723	$ 163,582
Employee contributions	17,046	8,541
Amortization of employer contributions	5,886	7,060
Gain (loss) on investment	3,464	(10,602)	$ 37,300
Employee distributions	(14,306)	(10,880)
Exchange rate fluctuations	(770)	(598)
Balance, end of year	178,043	166,723	$ 163,582
Less: current portion	(11,209)	(9,498)
Non-current portion	166,834	157,225
Lucas Group
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Acquisition of Lucas Group	$ 0	$ 9,620

Deferred Compensation Amortization Of Employer Contribution

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The compensation expense or income recognized during the period pertaining to the deferred compensation arrangement.

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

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Amount of liability, recognized in statement of financial position, for defined benefit pension plan, classified as noncurrent. Excludes other postretirement benefit 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 contributions received by defined benefit plan from participant which increase benefit obligation.

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Amount of increase in benefit obligation of defined benefit plan from business combination.

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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 foreign currency translation gain (loss) which (increases) decreases benefit obligation of defined benefit plan.

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