Earnings (Loss) Per Share (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	May 31, 2012		May 31, 2011		May 31, 2012		May 31, 2011
Earnings (Loss) Per Share [Abstract]
Net income (loss)	$ 14,407		$ (4,651)		$ 21,583		$ 6,939
Weighted average common shares outstanding - basic	59,936		61,842		60,736		61,723
Effect of dilutive employee stock options and unvested restricted stock units	25		158		31		150
Weighted average common shares - diluted	59,961		62,000		60,767		61,873
Net income (loss) per common share - basic	$ 0.24		$ (0.08)		$ 0.36		$ 0.11
Net income (loss) per common share - diluted	$ 0.24		$ (0.08)		$ 0.36		$ 0.11
Anti-dilutive securities excluded	7,382	[1]	6,457	[1]	7,269	[1]	6,621	[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.