Post-retirement Plan (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Feb. 01, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation			$ 50,827
Defined Benefit Plan Assets			52,082
Defined Benefit Plan, Funded (Unfunded) Status of Plan			$ 1,255
Defined Benefit Plan, Other Cost (Credit)	$ 100	$ 300
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation	$ 8,200	$ 8,200