Goodwill And Other Intangible Assets (Schedule Of Intangible Assets Purchased Through Business Acquisitions) (Details) (USD $) In Thousands, unless otherwise specified	Feb. 29, 2012	Aug. 31, 2011
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	$ 261,123	$ 217,573
Accumulated amortization	(134,720)	(128,467)
Net carrying amount	126,403	89,106
Contractual Agreements And Customer Relationships [Member]
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	123,145	85,131
Accumulated amortization	(58,061)	(53,365)
Net carrying amount	65,084	31,766
Intellectual Property [Member]
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	84,688	79,550
Accumulated amortization	(76,321)	(75,102)
Net carrying amount	8,367	4,448
Finite Lived Trade Names [Member]
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	2,700
Accumulated amortization	(338)
Net carrying amount	2,362
Indefinite Lived Trade Names [Member]
Indefinite-Lived And Finite-Lived Intangible Assets By Major Class [Line Items]
Gross carrying amount	50,590	52,892
Net carrying amount	$ 50,590	$ 52,892