Income Taxes (Details Of Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2011		Aug. 31, 2010		Aug. 31, 2009
Income Taxes [Abstract]
Income before income taxes	$ 238,958		$ 222,181		$ 212,122
Provision for income taxes	$ 67,912	[1]	$ 71,970	[2]	$ 67,172	[3]
Effective tax rate	28.40%		32.40%		31.70%

[1] Includes income tax benefits of $6 million from the reenactment of the U.S. Federal R&D credit in December 2010 and the finalization of the fiscal 2010 tax return.

[2] Includes income tax benefits of $1.3 million from the finalization of the fiscal 2009 tax return, adjustments to certain reserves to reflect the lapse of statute of limitations and higher levels of non-U.S. taxable income.

[3] Includes income tax benefits of $4.0 million from the reenactment of the U.S. Federal R&D credit in October 2008, finalizing prior year tax returns, adjusting certain reserves to reflect the lapse of statute of limitations and a benefit from repatriating foreign earnings to the U.S.