Amounts Reclassified from Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2013	Nov. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenue	$ 490,355	$ 415,374
Interest and foreign exchange	(4,744)	(5,900)
Total before tax	33,478	17,187
Tax expense	(10,522)	(4,586)
Net of tax	22,956	12,601
Unrealized Losses on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	269
Tax expense	(132)
Net of tax	137
Unrealized Losses on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive Income | Foreign exchange contracts
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenue	(150)
Unrealized Losses on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive Income | Interest rate swap contracts
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and foreign exchange	$ 419