Shareholders' Equity (Shares Repurchased Under Share Repurchase Program) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Class of Stock [Line Items]
Aggregate purchase price			$ 182.2
Treasury Stock [Member]
Class of Stock [Line Items]
Aggregate purchase price			182.2
Stock Repurchase Program Board Authorized Repurchases [Member]
Class of Stock [Line Items]
Shares repurchased	1.1	0.1	3.6	0.1
Aggregate purchase price	64.1	2.7	179.8	4.9
Average purchase price per share	$ 56.05	$ 42.01	$ 50.53	$ 40.81
Amount available for share repurchases under the share repurchase program			$ 335.9