Derivatives and Risk Management (Details 4) (USD $) In Thousands	12 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2009
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of taxes	$ 1,018	$ 370	$ 52
Commodity [Member] | Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of taxes	195	(7)	(284)
Foreign Exchange [Member] | SG&A expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of taxes	365	(81)	(122)
Interest Rate [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of taxes	$ 458	$ 458	$ 458