Deferred Compensation and Retirement Plans - Weighted-Average Assumptions Used In Calculating The Medical and Life Insurance Plan (Detail) - Medical And Life Insurance Benefits - Hay Group	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Discount rate, beginning of year	5.62%	4.85%	4.25%	2.54%
Discount rate, end of year	5.62%	4.85%	4.25%	2.54%
Healthcare care cost trend rate	6.50%	6.50%	6.00%

Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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- Definition

Ultimate trend rate for health care cost for defined benefit postretirement plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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