Pension and Other Employee Benefits (VEBA Trusts) (Details) - VEBA [Member]	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and PRB Plans [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%	100.00%
Fixed income securities
Defined Benefit Plans and PRB Plans [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	43.00%	42.00%
U.S. equities
Defined Benefit Plans and PRB Plans [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	38.00%	36.00%
International equities
Defined Benefit Plans and PRB Plans [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	10.00%	10.00%
Cash and cash equivalents
Defined Benefit Plans and PRB Plans [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	9.00%	12.00%