Net Periodic Pension Cost (Schedule of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net Periodic Pension Cost [Abstract]
Interest cost	$ 111	$ 128	$ 222	$ 256
Amortization of net loss	35	29	70	57
Expected return on plan assets	(161)	(162)	(323)	(323)
Net periodic pension cost	(15)	(5)	(31)	(10)
Contributed amount