Derivatives and Hedging Activities - Additional Information (Detail) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2013 USD ($)	Jan. 31, 2012 USD ($)	Jan. 31, 2013 USD ($)	Jan. 31, 2012 USD ($)	Jul. 31, 2012 USD ($)	Jul. 31, 2012 EUR (€)	Oct. 31, 2012 GBP-denominated interco debt [Member] GBP (£)	Oct. 31, 2012 Euro-denominated interco debt [Member] EUR (€)	May 13, 2010 Senior Unsecured Notes [Member] EUR (€)
Derivatives, Fair Value [Line Items]
Derivative maturity			18 months
Notional amount of outstanding forward exchange contracts	$ 130,282		$ 130,282		$ 61,169
Unrealized losses on foreign currency cash flow hedges expected to be reclassified to earnings within the next twelve months	(207)	1,010	(207)	1,010
Reclassification adjustment for (gains) losses included in net income	(90)	(142)	(557)	635
Total outstanding forward foreign exchange contracts	23,389		23,389		39,458
Net investment hedges to hedge portions of net investment						4,581	25,036	4,581	75,000
Outstanding forward foreign exchange contracts	8,050		8,050		10,650
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax			83	3,228
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ 42		$ 228