Impact of Derivatives for Foreign Currency Risk and Not Designated as Hedging Instruments on Earnings (Detail) (Forward foreign exchange contracts, Cost of revenue, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Forward foreign exchange contracts | Cost of revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	$ 2,907	$ 2,972