Employee Benefit Plans and Other Postretirement Benefits (Schedule Of Expected Benefit Payments For Next Five Years And Thereafter) (Details) $ in Thousands	Dec. 31, 2016 USD ($)
Pension Plan Assets
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
Expected benefit payments in 2017	$ 79,907
Expected benefit payments in 2018	81,133
Expected benefit payments in 2019	82,979
Expected benefit payments in 2020	85,528
Expected benefit payments in 2021	88,174
Expected benefit payments Thereafter	499,403
SERPA Benefits
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
Expected benefit payments in 2017	2,104
Expected benefit payments in 2018	2,240
Expected benefit payments in 2019	2,693
Expected benefit payments in 2020	3,169
Expected benefit payments in 2021	3,513
Expected benefit payments Thereafter	25,830
Postretirement Health Coverage
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
Expected benefit payments in 2017	30,130
Expected benefit payments in 2018	29,501
Expected benefit payments in 2019	28,529
Expected benefit payments in 2020	27,370
Expected benefit payments in 2021	26,094
Expected benefit payments Thereafter	$ 124,713