Retirement And Other Employee Benefits (Weighted Average Assumptions Used To Determine Net Periodic Benefit Cost) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets	6.75%
Qualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Effective discount rate for benefit obligations		4.09%	4.98%
Effective rate for interest on benefit obligations		4.09%	4.98%
Effective discount rate for service cost		4.09%	4.98%
Effective rate for interest on service cost		4.09%	4.98%
Expected long-term return on plan assets		6.75%	6.75%
2016 Plan 1
Defined Benefit Plan Disclosure [Line Items]
Effective discount rate for benefit obligations	4.56%
Effective rate for interest on benefit obligations	3.75%
Effective discount rate for service cost	4.34%
Effective rate for interest on service cost	3.62%
2016 Plan 2
Defined Benefit Plan Disclosure [Line Items]
Effective discount rate for benefit obligations	4.48%
Effective rate for interest on benefit obligations	3.74%
Effective discount rate for service cost	0.00%
Effective rate for interest on service cost	0.00%
Nonqualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Effective discount rate for benefit obligations	4.25%	3.77%	4.64%
Effective rate for interest on benefit obligations	3.44%	3.77%	4.64%
Effective discount rate for service cost	3.72%	3.77%	4.64%
Effective rate for interest on service cost	3.22%	3.77%	4.64%
Expected long-term return on plan assets	6.75%	6.75%	0.00%
Retirement Health Benefits
Defined Benefit Plan Disclosure [Line Items]
Effective discount rate for benefit obligations	4.53%	4.07%	4.99%
Effective rate for interest on benefit obligations	3.86%	4.07%	4.99%
Effective discount rate for service cost	0.00%	4.07%	4.99%
Effective rate for interest on service cost	0.00%	4.07%	4.99%
Expected long-term return on plan assets	6.75%	6.75%	6.75%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Assumed rates of compensation increases used to determine net period benefit cost	3.25%	3.25%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Assumed rates of compensation increases used to determine net period benefit cost	9.30%	9.30%