Pension Plans and Other Postretirement Benefits (Details 7) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Amortization of net actuarial loss	$ 129.0	$ 119.8	$ 81.2
Amortization to net income of net prior service cost (credit)	(15.2)	(11.8)	(7.0)
Remeasurements	384.9	(272.7)	(516.3)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning of year accumulated other comprehensive loss	(1,474.7)	(1,343.3)
Amortization of net actuarial loss	111.8	105.2
Amortization to net income of net prior service cost (credit)	3.0	6.4
Remeasurements	343.5	(243.0)
End of year accumulated other comprehensive loss	(1,016.4)	(1,474.7)
Net change in accumulated other comprehensive loss	458.3	(131.4)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning of year accumulated other comprehensive loss	(191.9)	(158.6)
Amortization of net actuarial loss	17.2	14.6
Amortization to net income of net prior service cost (credit)	(18.2)	(18.2)
Remeasurements	41.4	(29.7)
End of year accumulated other comprehensive loss	(151.5)	(191.9)
Net change in accumulated other comprehensive loss	$ 40.4	$ (33.3)