Organization and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Jul. 31, 2014 Office Country	Jul. 31, 2013	Apr. 30, 2014
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of offices	84
Number of countries in which entity operates	37
Investments in affiliated companies maximum	50.00%
Deferred revenue	$ 38,300,000		$ 36,800,000
Cash equivalents	104,400,000		186,600,000
Realized loss of other-than-temporary impairment	0	0
Payment of contingent consideration from acquisitions		15,000,000
Impairment of goodwill	0		0
Impairment of intangible assets	0		0
Performance related bonus expenses	39,000,000	31,200,000
(Decrease) increase in performance related bonus expenses	(300,000)	(700,000)
Performance related bonus after reduction in the previous year estimate	$ 38,700,000	$ 30,500,000
Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets estimated useful lives	2 years
Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets estimated useful lives	24 years