Pensions and Other Employee Benefits Plans (Components of Net Periodic Cost) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	$ 703	$ 722
Interest cost	[2]	1,765	2,018
Expected return on plan assets	[2]	(2,651)	(2,432)
Amortization of net actuarial loss (gain)	[2]	1,288	1,006
Net periodic cost		1,105	1,314
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	0	0
Interest cost	[2]	17	21
Expected return on plan assets	[2]	0	0
Amortization of net actuarial loss (gain)	[2]	11	2
Net periodic cost		$ 28	$ 23

[1] Included in general and administrative expenses.

[2] Included in other expense.