Fair Value Measurements (Schedule Of Financial Assets And Liabilities Measured At Fair Value) (Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 151,927	$ 143,444	$ 108,167	$ 83,418
Derivative assets	229	12
Derivative liabilities	(291)	(563)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	151,927	143,444
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	229	12
Derivative liabilities	(291)	(563)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents
Derivative assets
Derivative liabilities