Benefit Plans (Schedule of Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Retirement Benefits [Abstract]
Service cost	$ 79	$ 56	$ 112	$ 105
Interest cost	33	47	78	85
Actuarial gain recognized	(24)	(46)	(43)	(72)
Net periodic benefit cost	$ 88	$ 57	$ 147	$ 118