Employee Retirement Plans (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Amounts Recognized in Other Comprehensive Income (Loss)
Actuarial gain (loss)	$ 83.7	$ (48.1)	$ (47.3)
Amortization of actuarial loss	4.9	3.2	1.7
Amortization of prior service cost	0.1	0.1	0.1
Total before income taxes	88.7	(44.8)	(45.5)
Income tax expense (benefit)	32.9	(16.7)	(16.9)
Net amount recognized in other comprehensive income (loss)	$ 55.8	$ (28.1)	$ (28.6)