Employee Benefit Plans (Principal Assumptions In Developing Year-End Actuarial Present Value Of The Projected Benefit Obligation) (Details)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate	2.00%	2.20%
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	2.30%	2.90%
Rate of compensation increase (as a percent)	4.80%	4.90%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	2.30%	3.20%