Major Customers Who Accounted for 10% or More of Net Product and Engineering Revenue (Parenthetical) (Detail) (L-3)	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011		Jul. 31, 2010
Concentration Risk [Line Items]
Percentage of net product and engineering revenue	12.00%		[1]		[1]
Maximum
Concentration Risk [Line Items]
Percentage of net product and engineering revenue		10.00%		10.00%

[1] Total net revenue was less than 10% in this fiscal year.