Pension Benefits - Pension Benefit Payments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Unrecognized Postretirement Benefit Costs Arising During the Year	$ 61.6	$ (29.4)	$ (53.9)
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected Future Benefit Payments In 2013	24.4
Expected Future Benefit Payments in 2014	25.4
Expected Future Benefit Payments in 2015	26.7
Expected Future Benefit Payments in 2016	27.9
Expected Future Benefit Payments in 2017	29.1
Expected Future Benefit Payments in 2018-2022	163.4
Unrecognized Postretirement Benefit Costs Arising During the Year	53.8	(34.8)	(52.4)
Supplemental Employee Retirement Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Unrecognized Postretirement Benefit Costs Arising During the Year	$ 1.5	$ 1.3	$ 2.9