Restructuring - Additional Information (Detail) (USD $)	12 Months Ended
	Jul. 31, 2014 Employee	Jul. 31, 2013 Employee	Jul. 31, 2012 Employee
Restructuring Cost and Reserve [Line Items]
Restructuring, net	$ 6,557,000	$ 14,497,000	$ 6,416,000
Restructuring charge related to workforce reduction	6,300,000	13,400,000	4,800,000
Restructuring charge related to facility closed	300,000	1,100,000	1,600,000
Number of workforce reduction	181	465	270
Restructuring reversal	$ (152,000)	$ 253,000	$ 300,000