Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Nov. 30, 2015	Nov. 30, 2014
Earnings Per Share [Abstract]
Net income		$ 12,458	$ 10,085
Weighted average common shares outstanding – basic		50,221	53,360
Effect of dilutive employee stock options and unvested restricted stock units		1,104	1,467
Weighted average common shares - diluted		51,325	54,827
Net income per common share - basic		$ 0.25	$ 0.19
Net income per common share - diluted		$ 0.24	$ 0.18
Anti-dilutive securities excluded	[1]	412	455

[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.