Pensions and Other Employee Benefits Plans (Components of Net Periodic Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 173	$ 142
Interest cost	486	490
Expected return on plan assets	(532)	(512)
Amortization of net actuarial loss	232	196
Net periodic cost	359	316
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	5	5
Amortization of net actuarial loss	1	1
Amortization of prior service credits	6	6
Net periodic cost	$ 12	$ 12