Pension Benefits and Postretirement Benefits Other Than Pensions (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) employees	Mar. 31, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Total Expense (Benefit) Recognized	$ (1.4)	$ (1.1)
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Pension Plan, Number of Participants and Beneficiaries | employees	8,800
Defined Benefit Pension Plans, Number of Active Employees | employees	1,400
Service Cost	$ 0.0	0.0
Interest Cost on Projected Benefit Obligation	5.5	5.1
Expected Return on Plan Assets	(7.6)	(7.2)
Amortization of Net Actuarial Loss	$ 0.7	1.0
Postretirement Benefits Other than Pensions [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Postretirement Benefit Plan, Number of Retired Employees Covered | employees	700
Other Postretirement Benefit Plan, Number of Active Employees Covered | employees	600
Service Cost	$ 0.1	0.0
Interest Cost on Projected Benefit Obligation	0.1	0.1
Amortization of Prior Service Credit	(0.3)	(0.3)
Amortization of Net Actuarial Loss	(0.5)	(0.4)
Total Expense (Benefit) Recognized	$ (0.6)	$ (0.6)