Stock Repurchase Program (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended	6 Months Ended
	Oct. 13, 2011	Nov. 30, 2011	Feb. 29, 2012
Stock Repurchase Program [Abstract]
Shares repurchase authorized amount, maximum	$ 30.0
Shares acquired through stock repurchase program		1.5
Total cost for shares acquired through stock repurchase program		10.5
Remaining amount authorized for repurchase of shares			$ 19.5