Benefit Plans (Schedule Of Benefit Plans) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Pension Costs
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 508	$ 506	$ 1,016	$ 1,333
Interest cost	1,498	1,526	2,996	3,052
Expected return on plan assets	(1,310)	(1,354)	(2,620)	(2,708)
Amortization of prior service cost/benefit	0	1	0	2
Net cost	696	679	1,392	1,679
Postretirement Costs
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	4	2	8
Interest cost	272	315	543	630
Amortization of prior service cost/benefit	0	(43)	0	(86)
Net cost	$ 273	$ 276	$ 545	$ 552