Pensions and Other Employee Benefits Plans (Components of Net Periodic Cost) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	$ 722	$ 715
Interest cost	[2]	2,018	1,855
Expected return on plan assets	[2]	(2,432)	(2,628)
Amortization of net actuarial loss (gain)	[2]	1,006	1,041
Net periodic cost		1,314	983
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]		1
Interest cost	[2]	21	18
Amortization of net actuarial loss (gain)	[2]	2	8
Amortization of prior service cost (credit)	[2]		22
Net periodic cost		$ 23	$ 49

[1] Included in general and administrative expenses.

[2] Included in other expense.