Benefit Plans (Schedule Of Net Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Benefit Plans [Abstract]
Service cost	$ 317	$ 337	$ 377
Interest cost	667	701	695
Expected return on plan assets	(1,072)	(1,165)	(1,182)
Amortization of prior service cost		(94)	(126)
Recognized net actuarial loss	547	579	623
Net period cost	459	358	387
Effect of settlements loss		564
Total pension expense	$ 459	$ 922	$ 387