Deferred Compensation and Retirement Plans - Schedule of Fair Value Measurements of Defined Benefit Plan Assets (Detail) - Deferred compensation and pension plans - USD ($) $ in Thousands	Apr. 30, 2025	Apr. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	$ 18,567	$ 18,523
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	17,832	18,033
Money market funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	735	490
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	735	490
Level 1 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	0	0
Level 1 | Money market funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	735	490
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	17,832	18,033
Level 2 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	17,832	18,033
Level 2 | Money market funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	0	0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	0	0
Level 3 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	0	0
Level 3 | Money market funds
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan assets	$ 0	$ 0