Employee Benefit Plans and Other Postretirement Benefits (Schedule Of Net Periodic Benefit Cost Recognized In Accumulated And Other Comprehensive Income) (Details) $ in Thousands	Dec. 31, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Prior service cost (credit)	$ (2,475)
Net actuarial loss	511,054
Amounts included in other comprehensive income, net of tax	508,579
Postretirement Health Coverage
Defined Benefit Plan Disclosure [Line Items]
Prior service cost (credit)	(7,279)
Net actuarial loss	46,250
Amounts included in other comprehensive income, net of tax	38,971
Pension and SERPA Benefits
Defined Benefit Plan Disclosure [Line Items]
Prior service cost (credit)	4,804
Net actuarial loss	464,804
Amounts included in other comprehensive income, net of tax	$ 469,608