Annual report pursuant to Section 13 and 15(d)

Deferred Compensation and Retirement Plans - Additional Information (Detail)

v3.20.2
Deferred Compensation and Retirement Plans - Additional Information (Detail)
 12 Months Ended
Apr. 30, 2020
USD ($)
Person
Jurisdiction
Apr. 30, 2019
USD ($)
Person
Apr. 30, 2018
USD ($)
Defined Benefit Plan Disclosure [Line Items]      
Recognized investment income(expense) $ (1,800,000) $ 8,100,000 $ 10,300,000
Increase in market value of the underlying COLI investments 6,551,000 6,160,000 7,776,000
Net CSV 146,408,000 126,000,000  
CSV of COLI Contracts      
Defined Benefit Plan Disclosure [Line Items]      
Outstanding policy loans 92,300,000 93,200,000  
Total death benefits payable, net of loans 451,700,000 223,600,000  
Increase in market value of the underlying COLI investments 6,600,000 6,200,000 7,800,000
Net CSV $ 146,400,000 126,000,000.0  
Equity Securities | Minimum      
Defined Benefit Plan Disclosure [Line Items]      
Target allocation range 50.00%    
Equity Securities | Maximum      
Defined Benefit Plan Disclosure [Line Items]      
Target allocation range 60.00%    
Debt Securities | Minimum      
Defined Benefit Plan Disclosure [Line Items]      
Target allocation range 35.00%    
Debt Securities | Maximum      
Defined Benefit Plan Disclosure [Line Items]      
Target allocation range 45.00%    
Other Assets | Minimum      
Defined Benefit Plan Disclosure [Line Items]      
Target allocation range 1.00%    
Other Assets | Maximum      
Defined Benefit Plan Disclosure [Line Items]      
Target allocation range 11.00%    
Long Term Performance Unit Plan      
Defined Benefit Plan Disclosure [Line Items]      
Value per unit award $ 50,000    
Annual Benefit Payments per vested unit after anniversary period $ 25,000    
Number of payments after the seventh anniversary of the grant date 5 years    
Vesting percentage on each anniversary date 25.00%    
Enhanced Wealth Accumulation Plan      
Defined Benefit Plan Disclosure [Line Items]      
Participant contribution period towards deferred compensation plans (in years) 8 years    
Participant after tax contribution period towards deferred compensation plans (in years) 15 years    
Additional deferred units to acquire (in years) 5 years    
Medical and Life Insurance plan | Hay Group      
Defined Benefit Plan Disclosure [Line Items]      
Benefit plan, number of participants | Person 125    
Total benefit obligation $ 7,527,000 7,310,000 7,157,000
International Retirement Plans      
Defined Benefit Plan Disclosure [Line Items]      
Number of foreign jurisdictions | Jurisdiction 23    
Total benefit obligation $ 14,900,000 $ 14,700,000  
Long-term benefit obligation accrued, number of participants | Person 2,991 2,777  
Company's contributions $ 14,400,000 $ 13,300,000  
Executive Capital Accumulation Plan      
Defined Benefit Plan Disclosure [Line Items]      
Total benefit obligation 129,315,000 130,161,000 128,430,000
Company's contributions 9,000,000.0 8,500,000 6,200,000
Gain (loss) on deferred compensation plan (800,000) 8,700,000 11,100,000
Company's contributions, unamortized portion $ 17,000,000.0 16,800,000  
Executive Capital Accumulation Plan | Minimum      
Defined Benefit Plan Disclosure [Line Items]      
Deferred compensation arrangement vesting period 4 years    
Executive Capital Accumulation Plan | Maximum      
Defined Benefit Plan Disclosure [Line Items]      
Deferred compensation arrangement vesting period 5 years    
Defined Contribution Plan      
Defined Benefit Plan Disclosure [Line Items]      
Company's matching contributions $ 3,000,000.0 2,700,000  
Percentage contribution by the participants to defined contribution plan 50.00%    
Deferred Compensation Plan      
Defined Benefit Plan Disclosure [Line Items]      
Total benefit obligation $ 180,821,000 148,369,000 $ 126,494,000
Deferred Compensation Plan | CSV of COLI Contracts      
Defined Benefit Plan Disclosure [Line Items]      
Gross CSV 238,700,000 219,200,000  
Outstanding policy loans 92,300,000 $ 93,200,000  
Company Owned Life Insurance Held In Trust | CSV of COLI Contracts      
Defined Benefit Plan Disclosure [Line Items]      
Net CSV 117,200,000    
Total death benefits, net of loans held in trust $ 178,800,000