Pension Plans And Other Postretirement Benefits (Components Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 680	$ 812	$ 2,040	$ 2,436
Interest cost	2,954	2,874	8,862	8,622
Expected return on plan assets	(3,818)	(4,553)	(11,454)	(13,659)
Amortization of prior service cost	155	132	465	396
Amortization of actuarial loss	1,982	1,823	5,946	5,469
Net periodic benefit cost	1,953	1,088	5,859	3,264
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	205	262	615	786
Interest cost	750	708	2,250	2,124
Expected return on plan assets	(621)	(677)	(1,863)	(2,031)
Amortization of prior service cost	(116)	(127)	(348)	(381)
Amortization of actuarial loss	166	296	498	888
Net periodic benefit cost	$ 384	$ 462	$ 1,152	$ 1,386