Employee Benefit Plans (Schedule of Amounts that Will Be Amortized from Other Comprehensive Loss) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)	$ 9
Defined Benefit Plan, Future Amortization of Gain (Loss)	1,200
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year, Total	1,209
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)	(3)
Defined Benefit Plan, Future Amortization of Gain (Loss)	161
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year, Total	$ 158