Employee Benefits (Amounts Recognized in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss	$ 121,622	$ 112,532
Prior service benefit	(13,475)	(16,942)
Total	108,147	95,590
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss	10,153	9,300
Prior service benefit	(68)	(107)
Total	$ 10,085	$ 9,193