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Retirement Plans And Postretirement Benefits (Narrative) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2004
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Option to Remain in Plan, Period       5 years
Defined benefit plan, accumulated benefit obligation $ 121,800 $ 133,100    
Defined Contribution Plan, Employer Discretionary Contribution Amount 1,600 3,000 $ 3,000  
Mark-to-market adjustment $ (700) (3,000) 9,600  
Defined Benefit Plan, maximum salary increase       6.00%
Scenario, Adjustment        
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent 45.00%      
Plan        
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent 5.00%      
Union Carbide | GrafTech International Ltd        
Defined Benefit Plan Disclosure [Line Items]        
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions       50.00%
Postemployment Retirement Benefit        
Defined Benefit Plan Disclosure [Line Items]        
Employer contributions $ 1,400 1,300    
Defined Benefit Plan, Benefit Obligation 12,500 14,300    
Net Cost 500 2,000 (900)  
Mark-to-market adjustment $ 400 $ 1,100 $ 1,600