Derivatives And Risk Management (Derivative Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	May 31, 2013		Aug. 31, 2012
Derivatives, Fair Value [Line Items]
Derivative liabilities (accrued expenses, other payables and long-term liabilities)	$ 4,092	[1]	$ 3,547	[1]
Commodity [Member] | Designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities (accrued expenses, other payables and long-term liabilities)	130		2
Commodity [Member] | Not designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities (accrued expenses, other payables and long-term liabilities)	1,418		993
Foreign exchange [Member] | Designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities (accrued expenses, other payables and long-term liabilities)	542		1,272
Foreign exchange [Member] | Not designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities (accrued expenses, other payables and long-term liabilities)	2,002		1,248
Other [Member] | Not designated for hedge accounting [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities (accrued expenses, other payables and long-term liabilities)	$ 0		$ 32

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