Restructuring Charges - Additional Information (Detail) (USD $)	3 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014 Fiscal Year 2013 Restructuring Plan Employee	Jul. 31, 2014 Fiscal Year 2014 Restructuring Plan Employee
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ (58,000)	$ (39,000)	$ (100,000)	$ 2,900,000
Involuntarily terminated employees			115	48
Restructuring charges incurred to date			$ 4,000,000