Employee Benefits (Amounts Recognized in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss	$ 121,052	$ 118,963
Prior service benefit	(23,877)	(27,344)
Total	97,175	91,619
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss	10,073	9,592
Prior service benefit	(185)	(224)
Total	$ 9,888	$ 9,368