Pension, Savings, And Other Employee Benefits (Schedule Of Components Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Pension Benefits
Components of net periodic benefit cost
Service cost	$ 10	$ 10	$ 20	$ 19
Interest cost	6,987	7,380	13,973	14,759
Expected return on plan assets	(8,226)	(8,890)	(16,451)	(17,781)
Amortization of unrecognized:
Prior service cost/(credit)	0	13	0	26
Actuarial (gain)/loss	2,956	2,380	5,912	4,760
Net periodic benefit cost/(credit)	1,727	893	3,454	1,783
Other Benefits
Components of net periodic benefit cost
Service cost	34	27	67	54
Interest cost	327	325	654	651
Expected return on plan assets	(269)	(237)	(538)	(474)
Amortization of unrecognized:
Prior service cost/(credit)	0	24	0	48
Actuarial (gain)/loss	(91)	(143)	(182)	(285)
Net periodic benefit cost/(credit)	$ 1	$ (4)	$ 1	$ (6)