Pensions and Other Employee Benefits Plans (Components of Net Periodic Cost) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	$ 181	$ 178
Interest cost	[2]	440	510
Expected return on plan assets	[2]	(669)	(607)
Amortization of net actuarial loss (gain)	[2]	303	231
Net periodic cost		255	312
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	[2]	4	5
Amortization of net actuarial loss (gain)	[2]	(1)	(1)
Net periodic cost		$ 3	$ 4

[1] Included in general and administrative expenses.

[2] Included in other expense.