Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Amounts Recorded in AOCI on Consolidated Balance Sheets, Not Recognized as Components of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Pension Plans [Member]
Net loss	$ 49,476	$ 78,859
Prior service cost (credit)	103	166
Total amount unrecognized	49,579	79,025
OPEB [Member]
Net loss	2,075	15,947
Prior service cost (credit)	(285)	(1,164)
Total amount unrecognized	$ 1,790	$ 14,783