Summary of Significant Accounting Policies (Schedule of Other, Net) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accounting Policies [Abstract]
Interest and dividend income	$ 1,922	$ 1,745
Net periodic benefit cost other than the service costs	(253)	(490)
Impairment of debt securities available for sale	(586)	(39)
Other (expense) income	(32)	64
Other, net	$ 1,051	$ 1,280