Major Customers Who Accounted for 10% or More of Net Product and Engineering Revenue (Parenthetical) (Detail) (Siemens Ag)	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Concentration Risk [Line Items]
Percentage of net product and engineering revenue	10.00%		[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 period.