Summary of Net Accounts Receivable Due from customers Accounted for 10% or More Account Receivable (Detail)	Oct. 31, 2013	Jul. 31, 2013
Philips
Accounts Receivable [Line Items]
Percentage of net accounts receivable	17.00%	18.00%
L-3 Communications Security and Detection Systems
Accounts Receivable [Line Items]
Percentage of net accounts receivable	13.00%	16.00%