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Employee Benefit Plans (Components of Net Periodic Benefit Cost) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Pension Benefits [Member]    
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]    
Interest cost $ 358 $ 466
Expected return on plan assets (609) (555)
Amortization of unrecognized net (gain) loss 140 137
Total net periodic benefit cost $ (111) 48
Postretirement Benefit Plan [Member]    
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]    
Service cost   5
Interest cost   45
Amortization of prior service cost   4
Amortization of unrecognized net (gain) loss   (97)
Total net periodic benefit cost   $ (43)