Employee Benefit Plans and Other Postretirement Benefits (Schedule Of Net Periodic Benefit Cost Expected To Be Recognized) (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Prior service credit	$ (1,738)
Net actuarial loss	46,755
Amounts expected to be recognized in net periodic benefit cost, net of tax	45,017
Pension and SERPA Benefits
Defined Benefit Plan Disclosure [Line Items]
Prior service credit	(329)
Net actuarial loss	45,364
Amounts expected to be recognized in net periodic benefit cost, net of tax	45,035
Postretirement Health Coverage
Defined Benefit Plan Disclosure [Line Items]
Prior service credit	(1,409)
Net actuarial loss	1,391
Amounts expected to be recognized in net periodic benefit cost, net of tax	$ (18)