Derivatives and Hedging Activities - Additional Information (Detail) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2013 USD ($)	Oct. 31, 2012 USD ($)	Jul. 31, 2013 USD ($)	Oct. 31, 2013 GBP-denominated interco debt [Member] GBP (£)	May 13, 2010 Senior Unsecured Notes [Member] EUR (€)
Derivatives, Fair Value [Line Items]
Derivative maturity	18 months
Derivative, Notional Amount	$ 106,972		$ 157,500
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		557
Reclassification adjustment for (gains) losses included in net income	90	467
Total outstanding forward foreign exchange contracts	13,601
Net investment hedges to hedge portions of net investment				25,036	75,000
Amount Outstanding Forward Foreign Exchange Contracts Net Investment Hedge	4,500
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	244	5,301
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ 1,447	$ 186