Pensions and Other Employee Benefits Plans (Components of Net Periodic Cost) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	$ 187	$ 181
Interest cost	[2]	375	440
Expected return on plan assets	[2]	(688)	(669)
Amortization of net actuarial loss (gain)	[2]	399	303
Net periodic cost		273	255
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	0	0
Interest cost	[2]	3	4
Expected return on plan assets	[2]	0	0
Amortization of net actuarial loss (gain)	[2]	0	(1)
Net periodic cost		$ 3	$ 3

[1] Included in general and administrative expenses.

[2] Included in other expense.