Employee Benefits And Deferred Compensation Plans (Schedule Of Assumptions Used, Employee Pension Plan) (Details) - Pension Plans [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Discount rate for projected benefit obligation	3.95%	4.17%	3.83%
Discounted rate for net periodic pension cost	4.17%	3.83%	4.78%
Rate of increase in compensation levels
Expected long-term rate of return on plan assets	6.50%	7.50%	7.50%