Legal Proceedings - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended		1 Months Ended		12 Months Ended
	Oct. 17, 2013 Patents	May 05, 2004	Aug. 31, 2011	Jul. 31, 2014	Jul. 31, 2013 Aerotel Ltd [Member]	Mar. 15, 2013 Aerotel Ltd [Member]
Loss Contingencies [Line Items]
Number of patents	2
Damages and interest awarded			$ 10.1
Interest on damages per annum (Percentage)						9.00%
Total amount of Final Award damages						5.4
Accrued litigation expense				1.1
Term of indefeasible right to use		15 years
Payments for legal settlements					$ 5.4