Comprehensive Income (Loss) (Schedule of Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
The components of accumulated other comprehensive income (loss):
Total accumulated other comprehensive income (loss)	$ (11,195)	$ (4,146)	$ (2,932)	$ (5,107)
Unrealized gain (loss) on securities available for sale [Member]
The components of accumulated other comprehensive income (loss):
Total accumulated other comprehensive income (loss)	(11,513)	(2,211)	252
Deferred tax asset (liability)	2,691	517	(93)
Total accumulated other comprehensive income (loss)	(8,822)	(1,694)	159	(1,947)
Additional pension asset (liability) [Member]
The components of accumulated other comprehensive income (loss):
Total accumulated other comprehensive income (loss)	(3,097)	(3,200)	(4,907)
Deferred tax asset (liability)	724	748	1,816
Total accumulated other comprehensive income (loss)	$ (2,373)	$ (2,452)	$ (3,091)	$ (3,160)