Employee Benefit Plans (Schedule Of Assumptions Used To Develop Periodic Expense) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement Benefits [Abstract]
Discount rate	4.01%	4.11%	3.83%
Salary scale increases	3.50%	3.50%	3.50%
Long-term rate of return on assets	7.00%	7.00%	7.50%