Retirement Plans And Other Postretirement Benefits (Components Of Net Periodic Benefit Income Or Cost For Continuing Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Weighted-average assumptions used to determine benefit obligations:
Defined Benefit Plan Assumption Expected Long Term Return On Assets At Year End	5.00%
Pension Benefits
Weighted-average assumptions used to determine benefit obligations:
Discount rate	2.57%	3.27%	4.40%
Defined Benefit Plan Assumption Expected Long Term Return On Assets At Year End	5.00%	5.00%	6.00%
Weighted-average assumptions used to determine net periodic benefit cost:
Discount rate	3.27%	4.40%	3.72%
Expected long-term return on plan assets	5.00%	6.00%	6.50%
Components of net periodic benefit cost:
Service cost	$ 0	$ 0	$ 17
Interest cost	10,156	12,222	11,442
Expected return on plan assets	(11,004)	(13,528)	(15,011)
Amortization of prior service costs and gains or losses	15,494	10,891	13,894
Net periodic benefit cost	$ 14,646	$ 9,585	$ 10,342
Other Post-Retirement Benefits
Weighted-average assumptions used to determine benefit obligations:
Discount rate	2.54%	3.25%	4.37%
Weighted-average assumptions used to determine net periodic benefit cost:
Discount rate	3.25%	4.37%	3.69%
Components of net periodic benefit cost:
Service cost	$ 29	$ 26	$ 36
Interest cost	243	290	271
Expected return on plan assets	0	0	0
Amortization of prior service costs and gains or losses	(198)	(258)	(243)
Net periodic benefit cost	$ 74	$ 58	$ 64