Retirement, Postretirement And Other Benefit Plans (Summary Of Projected Benefits To Be Paid From Plan Assets Or From General Assets Using Current Actuarial Assumptions) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
2018	$ 28.0
2019	27.2
2020	29.0
2021	29.1
2022	28.0
2023 – 2027	138.0
Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
2018	2.9
2019	2.9
2020	2.8
2021	2.7
2022	2.6
2023 – 2027	11.4
Medicare Subsidy Receipts
Defined Benefit Plan Disclosure [Line Items]
2018	0.2
2019	0.3
2020	0.3
2021	0.3
2022	0.3
2023 – 2027	$ 0.5