Stockholders' Equity (Schedule Of Employee Stock Purchase Plan Weighted-Average Assumptions) (Details) (Employee Stock Purchase Plan [Member])	12 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2009
Employee Stock Purchase Plan [Member]
Expected dividend yield	0.90%	1.50%	1.50%
Risk-free interest rate	0.20%	0.30%	1.10%
Expected volatility	47.30%	79.70%	74.60%
Expected life, years	0.5	0.5	0.5