XML 64 R52.htm IDEA: XBRL DOCUMENT v3.7.0.1
Long-Term Debt - Additional Information (Detail) - USD ($)
3 Months Ended
Jun. 15, 2016
Jul. 31, 2017
Jul. 31, 2016
Apr. 30, 2017
Debt Instrument [Line Items]        
Principal payment on term loan facility   $ 5,156,000 $ 140,000,000  
Revolving Credit Facility        
Debt Instrument [Line Items]        
Line of credit facility borrowings   0   $ 0
Standby Letters of Credit        
Debt Instrument [Line Items]        
Long-term debt arrangement   3,000,000   3,000,000
Other Financial Institutions | Standby Letters of Credit        
Debt Instrument [Line Items]        
Long-term debt arrangement   8,800,000   8,100,000
Credit Agreement        
Debt Instrument [Line Items]        
Credit agreement initiation date Jun. 15, 2016      
Line of credit facility, maximum borrowing capacity $ 400,000,000      
Line of credit facility borrowings 275,000,000      
Principal payment on term loan facility 140,000,000      
Unamortized debt issuance costs   $ 3,400,000   3,500,000
Credit Agreement | London Interbank Offered Rate (LIBOR) | Minimum        
Debt Instrument [Line Items]        
Applicable margin on variable interest rate   1.25%    
Credit Agreement | London Interbank Offered Rate (LIBOR) | Maximum        
Debt Instrument [Line Items]        
Applicable margin on variable interest rate   2.00%    
Credit Agreement | Base Rate Loans | Minimum        
Debt Instrument [Line Items]        
Applicable margin on variable interest rate   0.25%    
Credit Agreement | Base Rate Loans | Maximum        
Debt Instrument [Line Items]        
Applicable margin on variable interest rate   1.00%    
Credit Agreement | Term Facility        
Debt Instrument [Line Items]        
Line of credit facility, maximum borrowing capacity $ 275,000,000      
Term loan amortization percentage year one 7.50%      
Term loan amortization percentage year two 7.50%      
Term loan amortization percentage year three 10.00%      
Term loan amortization percentage year four 10.00%      
Term loan amortization percentage year five 10.00%      
Principal payment on term loan facility   $ 5,200,000    
Average interest rate   2.34% 2.40%  
Long-term debt   $ 254,400,000   $ 259,500,000
Line of credit facility, maturity date   Jun. 15, 2021    
Credit Agreement | Term Facility | Minimum        
Debt Instrument [Line Items]        
Quarterly fee on average daily unused amount of Credit Facilities   0.20%    
Credit Agreement | Term Facility | Maximum        
Debt Instrument [Line Items]        
Quarterly fee on average daily unused amount of Credit Facilities   0.35%    
Credit Agreement | Revolving Credit Facility        
Debt Instrument [Line Items]        
Line of credit facility, maximum borrowing capacity $ 125,000,000      
Line of credit facility, maturity date   Jun. 15, 2021