Benefit Plans (Net Periodic Pension Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 65	$ 59
Interest cost	262	254
Expected return on plan assets	(257)	(252)
Recognized net actuarial loss	(133)	(128)
Recognized actuarial loss due to settlements	106
Net periodic cost	$ 309	$ 189
Obligation	3.61%	4.09%
Expense	4.09%	4.05%
Estimated 2018 Net Periodic Benefit Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 80
Interest cost	242
Expected return on plan assets	(267)
Amortization of net loss	136
Net periodic cost	$ 191