Fair Value of Financial Instruments - Summary of Fair Value Hierarchy for Financial Assets and Liabilities Measured Recurring Basis (Detail) $ in Thousands	Jul. 31, 2022 USD ($) CompensationPlan	Apr. 30, 2022 USD ($) CompensationPlan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	$ 2,375	$ 2,590
Financial Liabilities	$ 2,806	$ 3,003
Number of non-qualified compensation plans maintained | CompensationPlan	2	2
Non-qualified compensation plans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	$ 2,806	$ 3,003
Trading securities held in non-qualified compensation plans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	1,015	1,219
Cash surrender value of life insurance policies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	1,360	1,371
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	1,015	1,219
Financial Liabilities	0	0
Level 1 | Non-qualified compensation plans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	0	0
Level 1 | Trading securities held in non-qualified compensation plans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	1,015	1,219
Level 1 | Cash surrender value of life insurance policies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	1,360	1,371
Financial Liabilities	2,806	3,003
Level 2 | Non-qualified compensation plans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	2,806	3,003
Level 2 | Trading securities held in non-qualified compensation plans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	0	0
Level 2 | Cash surrender value of life insurance policies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	$ 1,360	$ 1,371