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Retirement Plans And Other Postretirement Benefits (Reconciliation Of Changes In Benefit Obligations And Plan Assets) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Assumption Expected Long Term Return On Assets At Year End | 6.50% |  |
Pension Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Assumption Expected Long Term Return On Assets At Year End | 6.50% | 6.50% | 7.00%
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] |  |  |
Benefit obligation, beginning of year | $ 303,126 | $ 303,852 |
Service cost | 194 | 231 | $ 530
Interest cost | 12,575 | 13,323 | 13,217
Effect of actuarial (gains) losses related to the following: |  |  |
Discount rate change | 21,055 | 9,296 |
Retirement rate assumptions and mortality table adjustments | (2,145) | (5,537) |
Other | (1,921) | (3,025) |
Benefits paid | 14,761 | 15,014 |
Benefit obligation, end of year | 318,123 | 303,126 | 303,852
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |  |
Plan assets at fair value, beginning of year | 214,559 | 210,642 |
Actual return on plan assets | 21,034 | 11,199 |
Employer contributions | 5,522 | 7,732 |
Benefits paid | 14,761 | 15,014 |
Plan assets at fair value, end of year | 226,354 | 214,559 | 210,642
Funded status of the plans | (91,769) | (88,567) |
Amounts recognized in the consolidated balance sheets: |  |  |
Net amount recognized | 91,769 | 88,567 |
Benefits paid | 14,761 | 15,014 |
Benefits paid | 14,761 | 15,014 |
Other Post-Retirement Benefits |  |  |
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] |  |  |
Benefit obligation, beginning of year | 7,436 | 7,745 |
Service cost | 33 | 38 | 44
Interest cost | 301 | 337 | 325
Effect of actuarial (gains) losses related to the following: |  |  |
Discount rate change | 471 | 210 |
Retirement rate assumptions and mortality table adjustments | 15 | (433) |
Other | (245) | (131) |
Plan participant contributions | 646 | 634 |
Benefits paid | 953 | 964 |
Benefit obligation, end of year | 7,704 | 7,436 | 7,745
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |  |
Plan assets at fair value, beginning of year | 0 | 0 |
Actual return on plan assets | 0 | 0 |
Employer contributions | 307 | 330 |
Plan participant contributions | 646 | 634 |
Benefits paid | 953 | 964 |
Plan assets at fair value, end of year | 0 | 0 | $ 0
Funded status of the plans | (7,704) | (7,436) |
Amounts recognized in the consolidated balance sheets: |  |  |
Net amount recognized | 7,704 | 7,436 |
Plan participant contributions | 646 | 634 |
Plan participant contributions | 646 | 634 |
Benefits paid | 953 | 964 |
Benefits paid | 953 | 964 |
Accrued Expenses | Pension Benefits |  |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |  |
Liability, Defined Benefit Plan, Current | 182 | 182 |
Accrued Expenses | Other Post-Retirement Benefits |  |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |  |
Liability, Defined Benefit Plan, Current | 457 | 453 |
Amounts recognized in the consolidated balance sheets: |  |  |
Liability, Defined Benefit Plan, Noncurrent | 7,247 | 6,983 |
Other Noncurrent Liabilities [Member] | Pension Benefits |  |  |
Amounts recognized in the consolidated balance sheets: |  |  |
Liability, Defined Benefit Plan, Noncurrent | $ 91,587 | $ 88,385 |

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