Product Information Table (Parenthetical) (Detail)	3 Months Ended		6 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Product Information [Line Items]
Percentage of net product and engineering revenue	67.00%	64.00%	69.00%	65.00%
Siemens Ag | Maximum
Product Information [Line Items]
Percentage of net product and engineering revenue	10.00%