Schedule of Intangible Assets Purchased Through Business Acquisitions (Detail) (USD $) In Thousands, unless otherwise specified	May 31, 2012	Aug. 31, 2011
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	$ 260,263	$ 217,573
Accumulated amortization	(138,121)	(128,467)
Net carrying amount	122,142	89,106
Indefinite lived trade names
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	50,590
Net carrying amount	50,590
Contractual agreements and customer relationships
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	122,340	85,131
Accumulated amortization	(60,900)	(53,365)
Net carrying amount	61,440	31,766
Intellectual property
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	84,688	79,550
Accumulated amortization	(76,560)	(75,102)
Net carrying amount	8,128	4,448
Trade Names
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	2,645	52,892
Accumulated amortization	(661)
Net carrying amount	$ 1,984	$ 52,892