Post-retirement Plan (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation	$ 49,559
Defined Benefit Plan Assets	50,761
Defined Benefit Plan, Funded Status of Plan	1,202
Defined Benefit Plan, Other Costs	100
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation	$ 8,000