Other Postretirement Employee Benefit Plans (Weighted Average Assumptions Used To Determine Benefit Obligations) (Details) - Other postretirement benefits	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.20%	3.50%
Medical trend rate - initial	6.00%	6.30%
Medical trend rate - grading period	19 years	20 years
Medical trend rate - ultimate	4.50%	4.50%