Derivatives And Risk Management (Derivative Assets) (Details) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2013		Aug. 31, 2012
Derivatives, Fair Value [Line Items]
Derivative assets (other current assets and other assets)	$ 3,027	[1]	$ 1,875	[1]
Commodity [Member] | Not designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative assets (other current assets and other assets)	1,923		407
Foreign exchange [Member] | Designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative assets (other current assets and other assets)	674		670
Foreign exchange [Member] | Not designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative assets (other current assets and other assets)	$ 430		$ 798

[1] * Derivative assets and liabilities do not include the hedged items designated as fair value hedges.