Employee Benefit Plans (Assumptions On A Weighted Average Basis, Used In Accounting For Plans) (Details)	12 Months Ended
	Dec. 31, 2017 Rate	Dec. 31, 2016 Rate	Dec. 31, 2015 Rate
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Determination of benefit obligation at year end, Discount rate	3.57%	4.05%	4.15%
Determination of benefit obligation at year end, Assumed credit on cash balance accounts	5.00%	5.00%	5.00%
Determination of net periodic benefit cost for year ended, Discount rate	3.95%	4.16%	3.95%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Effective Rate of Interest	3.28%	3.38%
Determination of net periodic benefit cost for year ended, Long-term rate of return on assets	6.00%	6.00%	6.00%
Determination of net periodic benefit cost for year ended, Assumed credit on cash balance accounts	5.00%	5.00%	5.00%