Pensions and Other Employee Benefits Plans (Pension Plans' Actual and Targeted Asset Allocations) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation	100.00%	100.00%
Target Allocation	100.00%
Target allocation range, maximum	100.00%
Liquid Return Seeking [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation	61.00%
Target Allocation	56.50%
Target allocation range, minimum	45.00%
Target allocation range, maximum	65.00%
Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation	9.00%
Target Allocation	14.50%
Target allocation range, minimum	0.00%
Target allocation range, maximum	20.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation	30.00%	43.00%
Target Allocation	29.00%
Target allocation range, minimum	20.00%
Target allocation range, maximum	40.00%