Derivatives And Risk Management (Derivatives Not Designated As Hedging Instruments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	$ 2,752	$ (2,966)	$ (1,171)	$ (16,014)
Commodity Contract [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	(3,336)	(5,754)	241	(16,040)
Foreign Exchange Contract [Member] | Net Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	(73)	14	(181)	(4)
Foreign Exchange Contract [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	(304)	289	(537)	869
Foreign Exchange Contract [Member] | SG&A Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes for derivatives not designated as hedges	$ 6,465	$ 2,485	$ (694)	$ (839)