Retirement Plans And Postretirement Benefits (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2003
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Option to Remain in Plan, Period				5 years
Defined benefit plan, accumulated benefit obligation	$ 133,100	$ 129,500
Defined Contribution Plan, Employer Discretionary Contribution Amount		3,000	$ 2,500
Mark-to-market adjustment	$ (3,000)	9,600	3,800
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	$ 1,300	1,200
Defined Benefit Plan, Benefit Obligation	14,300	13,500
Net Cost	2,000	900	500
Mark-to-market adjustment	$ 1,100	$ 1,600	$ 100