Pension Benefits and Postretirement Benefits Other Than Pensions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 2.6	$ 2.2
Interest Cost on Projected Benefit Obligation	6.4	6.2
Expected Return on Plan Assets	(8.8)	(8.7)
Amortization of Accumulated Net Unrecognized Pension Costs	5.8	2.3
Total Expense Recognized	6.0	2.0
Postretirement Benefits Other than Pensions [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	0	0.1
Interest Cost on Projected Benefit Obligation	0.3	0.3
Amortization of Accumulated Net Unrecognized Pension Costs	(0.4)	(0.3)
Total Expense Recognized	$ (0.1)	$ 0.1