Common Stock Stock Repurchase Programs (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Dec. 16, 2014	Jun. 13, 2014
Schedule of Common Stock Repurchases [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			800,000	4,000,000
Stock Repurchased During Period, Shares	89,400	2,529,615
Treasury Stock, Value, Acquired, Cost Method	$ 2.9	$ 79.9
Treasury Stock Acquired, Average Cost Per Share	$ 32.66	$ 31.57