Share-Based Payments (Details 9) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Shares issued under employee stock purchase plan
Shares issued under ESPP	245,000	274,000	434,000
Cash received under ESPP	$ 38.7	$ 28.7	$ 22.8