Quarterly report pursuant to Section 13 or 15(d)

Organization and Summary of Significant Accounting Policies - Additional Information (Detail)

v3.3.1.900
Organization and Summary of Significant Accounting Policies - Additional Information (Detail)
 3 Months Ended 6 Months Ended 12 Months Ended
Oct. 31, 2015
USD ($)
Country
Office
Oct. 31, 2014
USD ($)
Oct. 31, 2015
USD ($)
Country
Office
Oct. 31, 2014
USD ($)
Apr. 30, 2015
USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]          
Number of offices | Office 78   78    
Number of countries in which entity operates | Country 37   37    
Investments in affiliated companies maximum 50.00%   50.00%    
Deferred revenue $ 40,600,000   $ 40,600,000   $ 40,500,000
Cash equivalents 148,600,000   148,600,000   260,600,000
Realized loss of other-than-temporary impairment 0 $ 0 0 $ 0  
Impairment of goodwill     0   0
Impairment of intangible assets     0   $ 0
Performance related bonus expenses $ 44,600,000 $ 45,300,000 87,000,000 84,300,000  
(Decrease) increase in performance related bonus expenses     (600,000) (300,000)  
Performance related bonus after reduction in the previous year estimate     $ 86,400,000 $ 84,000,000  
Minimum          
Organization And Summary Of Significant Accounting Policies [Line Items]          
Intangible assets estimated useful lives     1 year    
Maximum          
Organization And Summary Of Significant Accounting Policies [Line Items]          
Intangible assets estimated useful lives     24 years