Derivatives and Risk Management (Details) (USD $) In Thousands	12 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2009
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes	$ (17,432)	$ (7,764)	$ 4,564
Commodity [Member] | Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes	(10,857)	(5,745)	14,666
Foreign Exchange [Member] | Net Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes	38	(898)	532
Foreign Exchange [Member] | Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes	1,412	(1,153)	26
Foreign Exchange [Member] | SG&A expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes	(8,025)	32	(9,816)
Other [Member] | Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes			(941)
Other [Member] | SG&A expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) before taxes			$ 97