Pensions and Other Employee Benefits Plans (Components of Net Periodic Cost) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Net periodic cost			$ 1,600
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	$ 715	702
Interest cost	[2]	1,855	1,961
Expected return on plan assets	[2]	(2,628)	(2,124)
Amortization of net actuarial loss (gain)	[2]	1,041	998
Net periodic cost		983	1,537
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[1]	1	1
Interest cost	[2]	18	21
Amortization of prior service cost (credit)	[2]	22	25
Amortization of net actuarial loss (gain)	[2]	8	10
Net periodic cost		$ 49	$ 57

[1] Included in general and administrative expenses.

[2] Included in other expense.