Net Periodic Pension Cost (Schedule of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Periodic Pension Cost [Abstract]
Interest cost	$ 106	$ 111	$ 318	$ 333
Amortization of net loss	26	37	79	107
Expected return on plan assets	(173)	(164)	(520)	(487)
Net periodic pension cost	(41)	(16)	(123)	(47)
Contributed amount