Annual report pursuant to Section 13 and 15(d)

Financial Instruments and Balance Sheet Classification (Detail)

v3.7.0.1
Financial Instruments and Balance Sheet Classification (Detail) - USD ($)
$ in Thousands
Apr. 30, 2017
Apr. 30, 2016
Apr. 30, 2015
Apr. 30, 2014
Investment Holdings [Line Items]        
Other Accrued Liabilities $ (148,464) $ (145,023)    
Cash and cash equivalents 410,882 273,252 $ 380,838 $ 333,717
Marketable Securities, Current 4,363 11,338    
Marketable securities, non-current 115,574 130,092    
Fair Value, Inputs, Level 1        
Investment Holdings [Line Items]        
Cost 524,700 415,840    
Unrealized Gains 6,697 1,395    
Unrealized Losses (578) (2,553)    
Fair Value 530,819 414,682    
Cash and cash equivalents 410,882 273,252    
Marketable Securities, Current 4,363 11,338    
Marketable securities, non-current 115,574 130,092    
Fair Value, Inputs, Level 1 | Cash        
Investment Holdings [Line Items]        
Cash and cash equivalents 409,824 269,558    
Cost 409,824 269,558    
Fair Value 409,824 269,558    
Fair Value, Inputs, Level 1 | Money Market Funds        
Investment Holdings [Line Items]        
Cash and cash equivalents 1,058 3,694    
Fair Value 1,058 3,694    
Cost 1,058 3,694    
Fair Value, Inputs, Level 1 | Mutual Funds        
Investment Holdings [Line Items]        
Unrealized Gains [1] 6,697 1,395    
Unrealized Losses [1] (578) (2,553)    
Marketable Securities, Current [1] 4,363 11,338    
Marketable securities, non-current [1] 115,574 130,092    
Cost [1] 113,818 142,588    
Fair Value [1] 119,937 141,430    
Fair Value, Inputs, Level 2 | Foreign Exchange Forward Contracts        
Investment Holdings [Line Items]        
Other Accrued Liabilities (717) (717)    
Unrealized Gains 129 324    
Unrealized Losses (846) (1,041)    
Fair Value (717) $ (717)    
Fair Value, Inputs, Level 2 | Interest Rate Swap        
Investment Holdings [Line Items]        
Unrealized Losses (947)      
Fair Value (947)      
Other Accrued Liabilities $ (947)      
[1] These investments are held in trust for settlement of the Company's vested and unvested obligations of $137.1 million and $138.8 million as of April 30, 2017 and 2016, respectively, under the ECAP (see Note 6 - Deferred Compensation and Retirement Plans). During fiscal 2017 and 2015, the fair value of the investments increased; therefore, the Company recognized income of $10.8 million and $8.8 million, respectively which was recorded in other income (loss), net. During fiscal 2016, the fair value of the investments decreased; therefore, the Company recognized a loss of $3.3 million, which was recorded in other income (loss), net.