Pensions and Other Employee Benefits Plans (Components of Net Periodic Cost) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	$ 165	$ 171	$ 352	$ 352
Interest cost	[2]	378	443	753	883
Expected return on plan assets	[2]	(679)	(657)	(1,367)	(1,326)
Amortization of net actuarial loss (gain)	[2]	341	341	740	644
Net periodic cost		205	298	478	553
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	0	0	0	0
Interest cost	[2]	3	4	6	8
Expected return on plan assets	[2]	0	0	0	0
Amortization of net actuarial loss (gain)	[2]	0	(1)	0	(2)
Net periodic cost		$ 3	$ 3	$ 6	$ 6

[1] Included in general and administrative expenses.

[2] Included in other expense.