Employee Benefit Plans and Other Postretirement Benefits (Schedule Of Expected Benefit Payments For Next Five Years And Thereafter) (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Pension Plan Assets
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Expected benefit payments in 2019	$ 111,980
Expected benefit payments in 2020	93,580
Expected benefit payments in 2021	95,690
Expected benefit payments in 2022	99,118
Expected benefit payments in 2023	102,190
Expected benefit payments 2024-2028	568,867
SERPA Benefits
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Expected benefit payments in 2019	2,314
Expected benefit payments in 2020	2,862
Expected benefit payments in 2021	3,272
Expected benefit payments in 2022	3,504
Expected benefit payments in 2023	4,467
Expected benefit payments 2024-2028	28,663
Postretirement Health Coverage
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Expected benefit payments in 2019	25,934
Expected benefit payments in 2020	27,328
Expected benefit payments in 2021	26,660
Expected benefit payments in 2022	25,378
Expected benefit payments in 2023	23,815
Expected benefit payments 2024-2028	$ 109,562