Employee Benefit Plans (Postretirement Health Coverage and Life Insurance Components of Net Period Benefit Costs) (Details) - Other Postretirement Benefit Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 50	$ 44	$ 68
Amortization of the net gain from earlier periods	(68)	(77)	(18)
Net periodic (benefit) cost	$ (18)	$ (33)	$ 50
Weighted-average assumptions
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.96%	3.26%	3.64%