Pensions and Other Employee Benefits Plans (Amounts Recognized in the Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current Liabilities	$ 0	$ 0
Long-Term Liabilities	19,724	17,013
Amounts recognized in the balance sheet	19,724	17,013
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current Liabilities	82	77
Long-Term Liabilities	457	434
Amounts recognized in the balance sheet	$ 539	$ 511