Summary of Charges Related to Accrued Restructuring Activity (Parenthetical) (Detail) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended							3 Months Ended	12 Months Ended
	May 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jul. 31, 2014		Jul. 31, 2013		Jul. 31, 2014 2013 Restructuring Plan	Jul. 31, 2013 2013 Restructuring Plan	Jul. 31, 2013 2011 Restructuring Plan	Jan. 31, 2014 Fiscal Two Thousand Thirteen Restructuring Plan	Jul. 31, 2014 Fiscal Two Thousand Thirteen Restructuring Plan	Jul. 31, 2014 2014 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charge	$ 3,500,000	$ 3,000,000	$ 500,000	$ 3,483,000		$ 3,519,000		$ (200,000)	$ 2,500,000		$ 600,000	$ 600,000	$ 2,900,000
Cash payments				2,500,000	[1],[2]	1,000,000	[1],[2]		700,000	300,000
Restructuring charge												$ (2,500,000)

[1] All activity prior to July 31, 2012 relates to the Fiscal Year 2011 Restructuring Plan. In fiscal year 2013, the restructuring charge of $3.5 million, and cash payments of $0.7 million relate to the Fiscal Year 2013 Restructuring Plan, while cash payments of $0.3 million relate to the Fiscal Year 2011 Restructuring Plan.

[2] 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.