Stock-based Compensation (Details 4) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Schedule of information on restricted stock units
Compensation expense	$ 23.3	[1]	$ 29.3	[1]	$ 15.2	[1]
Restricted Stock [Member]
Schedule of information on restricted stock units
Compensation expense	$ 7.0		$ 6.8		$ 5.0
Weighted-average fair value of grants, per share	$ 88.26		$ 77.26		$ 48.45

[1] Stock-Based compensation expense was recorded in our Corporate and other business segment.