Pensions and Other Postretirement Benefits (Unrecognized Actuarial Gains and Losses) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss	$ 6,500	$ 5,237
Unrecognized prior service cost	62	9
Unamortized transition obligation	1	2
Benefit plans, accumulated other comprehensive income (loss) before tax	6,563	5,248
OPEB Plans
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss	1,808	2,095
Unrecognized prior service cost		0
Unamortized transition obligation		0
Benefit plans, accumulated other comprehensive income (loss) before tax	$ 1,808	$ 2,095