Pension Benefits and Postretirement Benefits Other Than Pensions (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 2.7	$ 2.1	$ 7.9	$ 6.5
Interest Cost on Projected Benefit Obligation	6.5	6.2	19.3	18.6
Expected Return on Plan Assets	(8.8)	(8.7)	(26.3)	(26.2)
Amortization of Accumulated Net Unrecognized Pension Costs	6.1	2.5	18.3	7.3
Total Expense (Benefit) Recognized	6.5	2.1	19.2	6.2
Postretirement Benefits Other than Pensions [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	0.0	0.0	0.1	0.1
Interest Cost on Projected Benefit Obligation	0.3	0.3	0.8	0.9
Amortization of Accumulated Net Unrecognized Pension Costs	(0.4)	(0.5)	(1.1)	(1.4)
Total Expense (Benefit) Recognized	$ (0.1)	$ (0.2)	$ (0.2)	$ (0.4)