Net Periodic Benefit Costs (Schedule Of Net Periodic Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plan	$ 0
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	54	$ 55
Expected return on plan assets	(69)	(65)
Amortization of the net loss	23	22
Net periodic cost (benefit)	8	12
Supplemental Executive Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	42	47
Interest cost	34	36
Amortization of prior service cost	8	8
Amortization of the net loss	20	34
Net periodic cost (benefit)	$ 104	$ 125