Product Information Table (Detail)	3 Months Ended
	Oct. 31, 2012	Oct. 31, 2011
Product Information [Line Items]
Percentage of net product and engineering revenue	71.00%	62.00%
Philips
Product Information [Line Items]
Percentage of net product and engineering revenue	17.00%	16.00%
Toshiba
Product Information [Line Items]
Percentage of net product and engineering revenue	11.00%	12.00%
Siemens Ag
Product Information [Line Items]
Percentage of net product and engineering revenue		11.00%