Description Of Business And Significant Accounting Policies (Schedule Of Financial Assets And Liabilities Measured At Fair Value)(Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2009
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 143,444	$ 108,167	$ 83,418	$ 85,929
Derivative assets	12
Derivative liabilities	(563)	(634)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	143,444	108,167
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	12
Derivative liabilities	$ (563)	$ (634)