XML 52 R42.htm IDEA: XBRL DOCUMENT v3.5.0.2
Deferred Compensation and Retirement Plans - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Oct. 31, 2016
Oct. 31, 2015
Oct. 31, 2016
Oct. 31, 2015
Apr. 30, 2016
Defined Benefit Plan Disclosure [Line Items]          
Increase in market value of the underlying COLI investments     $ 3,172 $ 3,295  
Recognized investment income(expense) $ (700) $ (2,500) 3,226 (1,818)  
CSV of COLI Contracts          
Defined Benefit Plan Disclosure [Line Items]          
Gross CSV 179,200   179,200   $ 175,700
Outstanding policy loans 68,400   68,400   $ 68,400
Increase in market value of the underlying COLI investments 700 800 3,200 3,300  
Executive Capital Accumulation Plan          
Defined Benefit Plan Disclosure [Line Items]          
(Loss) gain on deferred compensation plan $ (600) $ (1,600) $ 2,600 $ (900)  
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