Earnings Per Share (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Nov. 30, 2011		Nov. 30, 2010
Earnings Per Share [Abstract]
Net income	$ 5,499		$ 7,242
Weighted average common shares outstanding - basic	61,693		61,639
Effect of dilutive employee stock options and unvested restricted stock units	44		114
Weighted average common shares - diluted	61,737		61,753
Net income per common share - basic	$ 0.09		$ 0.12
Net income per common share - diluted	$ 0.09		$ 0.12
Anti-dilutive securities excluded	7,146	[1]	7,044	[1]

[1] Anti-dilutive securities consist of stock options and unvested restricted stock units that were not included in the computation of diluted earnings per share because either the exercise price of the options was greater than the average market price of the common stock or the total assumed proceeds under the treasury stock method resulted in negative incremental shares and thus the inclusion would have been anti-dilutive.