Employee Benefit Plans (Schedule Of Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Benefit Plans [Abstract]
Annual increase in cost of benefits	5.60%	5.70%	5.80%
Discount rate used to determine year-end obligations	3.50%	3.90%	3.30%
Discount rate used to determine year-end expense	3.90%	3.30%	3.30%