Defined Benefit Plans (Schedule of Net Periodic Pension Cost )(Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of net periodic pension cost
Service cost	$ 251	$ 295	$ 737	$ 883
Interest cost	59	62	172	185
Expected return on plan assets	(258)	(296)	(757)	(885)
Prior service cost amortization	38	38	113	113
Deferred loss amortization	0	61	0	183
Net periodic pension cost	$ 90	$ 160	$ 265	$ 479