Summary of Charges Related to Accrued Restructuring Activity (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Jul. 31, 2014	Jan. 31, 2014	Jul. 31, 2015		Jul. 31, 2014		Jul. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring Charge				$ (354)	[1],[2]	$ 3,483	[1],[2]	$ 3,519
Cash payments	[1],[2]			2,800		2,500
Restructuring adjustments	[1],[2]			(400)
2014 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring Charge		$ 2,900		(300)		2,900
Cash payments				(2,400)
Restructuring adjustments				(300)
2013 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring Charge						600
Cash payments						2,500
2013 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring Charge			$ 600	(100)		$ (200)		$ 2,500
Cash payments				(500)
Restructuring adjustments				$ (100)

[1] Activity in fiscal year 2014 pertains to both the Fiscal Year 2014 Restructuring Plan and the 2013 Restructuring Plan. In fiscal year 2014, the restructuring charges of $2.9 million relate to the Fiscal Year 2014 Restructuring Plan, while restructuring charges of $0.6 million and cash payments of ($2.5) million relate to the Fiscal Year 2013 Restructuring Plan.

[2] Activity in fiscal year 2015 pertains to both the Fiscal Year 2014 Restructuring Plan and the 2013 Restructuring Plan. In fiscal year 2015, the restructuring adjustments of ($0.3) million and cash payments of ($2.4) million relate to the Fiscal Year 2014 Restructuring Plan, while restructuring adjustments of ($0.1) million and cash payments of ($0.5) million relate to the Fiscal Year 2013 Restructuring Plan.