Shareholders' Equity (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Shareholders' Equity [Abstract]
Number of shares authorized to be repurchased	3.5
Shares issued during the period	6.7	2.3	1.7
Common stock reissued	0.5	2.1	1.7
Treasury Stock, Shares, Acquired	0.4	0.4	1.7
Treasury Stock, Value, Acquired, Cost Method	$ 13.7	$ 11.4	$ 48.5