Impact of Derivatives for Foreign Currency Risk and Designated as Hedging Instruments on Accumulated Other Comprehensive Income (Loss) and Earnings (Detail) (Forward foreign exchange contracts, USD $)	6 Months Ended
	Feb. 28, 2013	Feb. 29, 2012
Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	$ (1,795,000)	$ 2,179,000
Amount of Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	(2,394,000)	1,701,000
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	132,000	(34,000)
Cost of revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	2,287,000	2,618,000
Amount of Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	3,663,000	1,530,000
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	4,140,000	(1,704,000)
Selling, general and administrative
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	17,000	(1,684,000)
Amount of Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	303,000	(2,556,000)
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$ 139,000	$ 83,000