Net Periodic Pension Cost (Schedule of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net Periodic Pension Cost [Abstract]
Interest cost	$ 111	$ 128	$ 333	$ 384
Amortization of net loss	37	28	107	85
Expected return on plan assets	(164)	(162)	(487)	(485)
Net periodic pension cost	(16)	(6)	(47)	(16)
Contributed amount		$ 409		$ 409