Retirement And Other Employee Benefits (Summary Of Health Care Cost Trend Rates) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate assumed for next year, post-65 reimbursement plan, prescriptions	10.20%	8.00%	8.50%
Retirement Health Benefits
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate assumed for next year, pre-65 non-reimbursement plan	9.30%	8.10%	8.70%
Health care cost trend rate assumed for next year, post-65 non-reimbursement plan	5.70%	8.00%	8.50%
Health care cost trend rate assumed for next year, pre-65 reimbursement plan	8.10%	8.10%	8.70%
Health care cost trend rate assumed for next year, post-65 reimbursement plan	8.10%	8.10%	8.70%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50%	4.50%	4.50%
Year that the rate reaches the ultimate trend rate, pre-65, non-reimbursement plan	2030	2028	2028
Year that the rate reaches the ultimate trend rate, post-65, non-reimbursement plan	2030	2028	2028
Year that the rate reaches the ultimate trend rate, pre-65, reimbursement plan	2030	2028	2028
Year that the rate reaches the ultimate trend rate, post-65, reimbursement plan	2030	2028	2028