Retirement, Other Postretirement Benefits, And Defined Contribution Plans (Actuarial Assumptions Used In Determining Net Periodic And Other Postretirement Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-Qualified Pension Plans [Member]
Defined Benefit Plan, Accumulated Benefit Obligation	$ 131.9	$ 144.7
Qualified Pension Plans [Member]
Defined Benefit Plan, Accumulated Benefit Obligation	$ 6,900.0	$ 7,400.0
Net Periodic Pension And Other Postretirement Benefit Costs [Member]
Weighted-average rate of increase in future compensation levels	3.98%	3.98%	4.23%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.75%	4.75%	4.75%
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Pre-65 Retirees [Member]
Assumed health care cost trend rate	6.95%	6.55%	6.75%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2027	2026	2024
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Post - 65 Retirees [Member]
Assumed health care cost trend rate	7.25%	7.25%	7.55%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2027	2026	2024
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Non-Qualified Pension Plans [Member] | Service Cost [Member]
Weighted-average discount rate	3.35%	3.65%	3.65%
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Non-Qualified Pension Plans [Member] | Interest Cost [Member]
Weighted-average discount rate	2.76%	3.10%	3.10%
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Qualified Pension Plans [Member] | Service Cost [Member]
Weighted-average discount rate	3.89%	4.75%	5.00%
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Qualified Pension Plans [Member] | Interest Cost [Member]
Weighted-average discount rate	3.44%	3.73%	3.90%
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Other Postretirement Benefits Plan [Member] | Service Cost [Member]
Weighted-average discount rate	3.88%	4.60%	4.92%
Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Other Postretirement Benefits Plan [Member] | Interest Cost [Member]
Weighted-average discount rate	3.33%	3.61%	3.78%
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member]
Weighted-average rate of increase in future compensation levels	3.98%	3.98%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.75%	4.75%
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member] | Pre-65 Retirees [Member]
Assumed health care cost trend rate	6.59%	6.95%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2027	2027
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member] | Post - 65 Retirees [Member]
Assumed health care cost trend rate	7.15%	7.25%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2026	2027
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member] | Non-Qualified Pension Plans [Member]
Weighted-average discount rate	3.98%	3.34%
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member] | Qualified Pension Plans [Member]
Blended weighted-average discount rate	4.47%	3.78%
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member] | Other Postretirement Benefits Plan [Member]
Weighted-average discount rate	4.42%	3.72%
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member] | Minimum [Member] | Qualified Pension Plans [Member]
Weighted-average discount rate	4.37%	3.70%
Pension Postretirement Benefit Obligations And Other Postretirement Accumulated Postretirement Benefit Obligations [Member] | Maximum [Member] | Qualified Pension Plans [Member]
Weighted-average discount rate	4.52%	3.82%
Pension Assets [Member] | Net Periodic Pension And Other Postretirement Benefit Costs [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	7.50%	7.50%	7.75%
Other Postretirement Non Taxable Assets [Member] | Net Periodic Pension And Other Postretirement Benefit Costs [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets			7.75%
Other Postretirement Non Taxable Assets [Member] | Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Minimum [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.50%	6.50%
Other Postretirement Non Taxable Assets [Member] | Net Periodic Pension And Other Postretirement Benefit Costs [Member] | Maximum [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	7.50%	7.50%
Taxable [Member] | Net Periodic Pension And Other Postretirement Benefit Costs [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	5.50%	5.75%	6.00%