Share Repurchases (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2015	May. 31, 2014	Jan. 03, 2014
Share Repurchases [Abstract]
Repurchase authorization amount					$ 150.0
Number of shares of common stock repurchased during the period	371,886	129,104	977,812	207,624
Aggregate purchase price of shares repurchased	$ 29.1	$ 11.2	$ 78.5	$ 17.8
Remaining amount available under the repurchase program	$ 30.5		$ 30.5