Pensions And Other Postretirement Benefits (Pension Plan Weighted-Average Asset Allocations, By Asset Category) (Details)	Dec. 31, 2017	Dec. 31, 2016
Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	100.00%	100.00%
Equity Securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	25.00%	24.00%
Equity Securities | Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	49.00%	51.00%
Debt Securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	39.00%	33.00%
Debt Securities | Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	24.00%	23.00%
Cash and Cash Equivalents | Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	2.00%	2.00%