Debt (Schedule Of Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2012	Aug. 31, 2011
Debt Instrument [Line Items]
Total long-term debt	$ 481,793	$ 497,013
Other	543	763
Less long-term debt due within one year	(15,180)	(15,178)
Long-term debt due after one year	466,613	481,835
2011 Fixed Rate Notes [Member]
Debt Instrument [Line Items]
Total long-term debt	481,250	496,250
2011 Variable Rate Notes [Member]
Debt Instrument [Line Items]
Total long-term debt