Pension And Other Post-Retirement Benefits (Schedule Of Components Of Net Periodic Benefit Cost For Pension And Other Post-Retirement Benefit Programs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	2,535	3,068	5,070	6,135
Expected return on plan assets	(2,804)	(3,404)	(5,608)	(6,808)
Amortization of prior service costs, (gains) losses and net transition asset	3,814	2,730	7,628	5,459
Net periodic benefit cost	3,545	2,394	7,090	4,786
Other Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	8	18	16
Interest cost	60	73	120	146
Expected return on plan assets	0	0	0	0
Amortization of prior service costs, (gains) losses and net transition asset	(47)	(57)	(94)	(115)
Net periodic benefit cost	$ 22	$ 24	$ 44	$ 47