Stock Transactions Stock Transactions (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jul. 31, 2015
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Shares, Acquired	252,642	2,538,718
Treasury Stock, Value, Acquired, Cost Method	$ 23.5	$ 230.1
Stock Repurchase Program, Authorized Amount	450.0	$ 300.0	$ 150.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 46.4