Derivatives And Risk Management (Derivatives Not Designated As Hedging Instruments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	$ 2,888	$ (17,432)	$ (7,764)
Commodity [Member] | Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	4,496	(10,857)	(5,745)
Foreign exchange [Member] | Net sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	(199)	38	(898)
Foreign exchange [Member] | Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	(537)	1,412	(1,153)
Foreign exchange [Member] | SG&A expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	$ (872)	$ (8,025)	$ 32