| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | GRAFTECH INTERNATIONAL LTD. |
| Entity Central Index Key | 0000931148 |
| Pay vs Performance Disclosure Unit_pure in Thousands | 12 Months Ended | ||
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | |
| Pay vs Performance Disclosure [Table] | |||
| Pay vs Performance [Table Text Block] | Pay Versus Performance Year Summary (1) ($) Compensation (2) ($) Summary (3) ($) Compensation (2) ($) Average Non-PEO (4) ($) Average Non-PEO (5) ($) Value of Initial Fixed $100 Net (in ($) Adjusted (6) (in 000s) ($) GrafTech Total NYSE Arca Steel Index Total Return 2022 1,407,268 1,153,710 1,406,150 1,405,993 1,538,305 1,097,819 $42 $179 382,962 536,464 2021 N/A N/A 3,445,257 4,377,435 6,471,272 6,656,296 $104 $156 388,330 669,940 2020 N/A N/A 2,433,525 2,691,429 1,146,426 1,248,844 $93 $121 434,374 658,946 (1) Mr. Kessler joined the Company as our CEO and President on July 1, 2022 and therefore information is not provided for years 2021 or 2020 because he was not our PEO during those years. Our principle executive officer is referred to as the “PEO” in this disclosure. (2) “Compensation actually paid” to our CEO and former CEO in each of 2022 , 202 2020 2021 2022 Kessler Rintoul Kessler Rintoul Kessler Rintoul SCT Total Compensation - $2,433,525 - $3,445,257 $1,407,268 $1,406,150 Less: Stock Award Values Reported in SCT for the Covered Year - $(765,850) - $(1,170,960) $(446,112) - Less: Option Award Values Reported in SCT for the Covered Year - $(259,307) - $(662,909) $(244,961) - Plus: Year-End - $1,426,122 - $903 $437,515 $255 Year-End - $85,601 - - - $(412) Change in Fair Value of Stock and Option Awards from Prior Years that Vested in the Covered Year - $(145,001) - $675,793 - - Fair Value for Stock and Option Awards Granted and Vested in the Covered Year - $(83,661) - $2,089,351 - - Less: Fair Value of Stock and Option Awards Forfeited in the Covered Year - - - - - - Compensation Actually Paid - $2,691,429 - $4,377,435 $1,153,710 $1,405,993 (3) Mr. Rintoul resigned from the Company as our CEO and President on June 30, 2022. (4) The identity of the non-PEO Year Non-PEO 2020 Quinn J. Coburn, Jeremy S. Halford, Iñigo Perez Ortiz, Gina K. Gunning 2021 Timothy K. Flanagan, Quinn J. Coburn, Jeremy S. Halford, Iñigo Perez Ortiz, Gina K. Gunning 2022 Timothy K. Flanagan, Jeremy S. Halford, Iñigo Perez Ortiz, Gina K. Gunning (5) Average “compensation actually paid” for our non-PEO non-PEO non-PEO 2020 2021 2022 Non-PEO NEOs Non-PEO NEOs Non-PEO NEOs SCT Total Compensation $1,146,426 $6,471,272 $1,538,305 Less: Stock Award Values Reported in SCT for the Covered Year $(238,765) $(334,400) $(525,690) Less: Option Award Values Reported in SCT for the Covered Year $(80,843) $(194,973) $(228,750) Plus: Year-End $442,880 - $331,139 Year-End $5,333 $(1,126) $(10,251) Change in Fair Value of Stock and Option Awards from Prior Years that Vested in the Covered Year $(26,400) $108,379 $(6,934) Fair Value for Stock and Option Awards Granted and Vested in the Covered Year $213 $617,144 - Less: Fair Value of Stock and Option Awards Forfeited in the Covered Year - - - Compensation Actually Paid $1,248,844 $6,656,296 $1,097,819 (6) A non-GAAP Compensation Discussion and Analysis | ||
| Company Selected Measure Name | adjusted EBITDA | ||
| Named Executive Officers, Footnote [Text Block] | The identity of the non-PEO Year Non-PEO 2020 Quinn J. Coburn, Jeremy S. Halford, Iñigo Perez Ortiz, Gina K. Gunning 2021 Timothy K. Flanagan, Quinn J. Coburn, Jeremy S. Halford, Iñigo Perez Ortiz, Gina K. Gunning 2022 Timothy K. Flanagan, Jeremy S. Halford, Iñigo Perez Ortiz, Gina K. Gunning | ||
| Adjustment To PEO Compensation, Footnote [Text Block] | “Compensation actually paid” to our CEO and former CEO in each of 2022 , 202 2020 2021 2022 Kessler Rintoul Kessler Rintoul Kessler Rintoul SCT Total Compensation - $2,433,525 - $3,445,257 $1,407,268 $1,406,150 Less: Stock Award Values Reported in SCT for the Covered Year - $(765,850) - $(1,170,960) $(446,112) - Less: Option Award Values Reported in SCT for the Covered Year - $(259,307) - $(662,909) $(244,961) - Plus: Year-End - $1,426,122 - $903 $437,515 $255 Year-End - $85,601 - - - $(412) Change in Fair Value of Stock and Option Awards from Prior Years that Vested in the Covered Year - $(145,001) - $675,793 - - Fair Value for Stock and Option Awards Granted and Vested in the Covered Year - $(83,661) - $2,089,351 - - Less: Fair Value of Stock and Option Awards Forfeited in the Covered Year - - - - - - Compensation Actually Paid - $2,691,429 - $4,377,435 $1,153,710 $1,405,993 | ||
| Non-PEO NEO Average Total Compensation Amount | $ 1,538,305 | $ 6,471,272 | $ 1,146,426 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 1,097,819 | 6,656,296 | 1,248,844 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | Average “compensation actually paid” for our non-PEO non-PEO non-PEO 2020 2021 2022 Non-PEO NEOs Non-PEO NEOs Non-PEO NEOs SCT Total Compensation $1,146,426 $6,471,272 $1,538,305 Less: Stock Award Values Reported in SCT for the Covered Year $(238,765) $(334,400) $(525,690) Less: Option Award Values Reported in SCT for the Covered Year $(80,843) $(194,973) $(228,750) Plus: Year-End $442,880 - $331,139 Year-End $5,333 $(1,126) $(10,251) Change in Fair Value of Stock and Option Awards from Prior Years that Vested in the Covered Year $(26,400) $108,379 $(6,934) Fair Value for Stock and Option Awards Granted and Vested in the Covered Year $213 $617,144 - Less: Fair Value of Stock and Option Awards Forfeited in the Covered Year - - - Compensation Actually Paid $1,248,844 $6,656,296 $1,097,819 | ||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | |||
| Compensation Actually Paid vs. Net Income [Text Block] | |||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | |||
| Tabular List [Table Text Block] | Tabular List of Performance Measures Listed below is the performance measure that in our assessment represents the most important performance measure used by us to link compensation actually paid to our named executive officers for 2022 to Company performance. Performance Measure Nature Explanation Adjusted EBITDA Financial Measure A non-GAAP | ||
| Total Shareholder Return Amount | $ 42 | 104 | 93 |
| Peer Group Total Shareholder Return Amount | 179 | 156 | 121 |
| Net Income (Loss) | $ 382,962,000 | $ 388,330,000 | $ 434,374,000 |
| Company Selected Measure Amount | 536,464 | 669,940 | 658,946 |
| Measure [Axis]: 1 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Adjusted EBITDA | ||
| Non-GAAP Measure Description [Text Block] | A non-GAAP | ||
| Kessler [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| PEO Total Compensation Amount | $ 1,407,268 | ||
| PEO Actually Paid Compensation Amount | $ 1,153,710 | ||
| PEO Name | Mr. Kessler | ||
| Kessler [Member] | Year-end Fair Value Of Awards Granted In The Current Fiscal Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | $ 437,515 | ||
| Kessler [Member] | Stock Award Values Reported in SCT for the Covered Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (446,112) | ||
| Kessler [Member] | Option Award Values Reported in SCT for the Covered Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (244,961) | ||
| Rintoul [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| PEO Total Compensation Amount | 1,406,150 | $ 3,445,257 | $ 2,433,525 |
| PEO Actually Paid Compensation Amount | $ 1,405,993 | 4,377,435 | 2,691,429 |
| PEO Name | Mr. Rintoul | ||
| Rintoul [Member] | Year-end Fair Value Of Awards Granted In The Current Fiscal Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | $ 255 | 903 | 1,426,122 |
| Rintoul [Member] | Change In Fair Value Of Outstanding And Unvested Awards Granted In Prior Fiscal Years [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (412) | 85,601 | |
| Rintoul [Member] | Change In Fair Value As Of Vesting Date Of Awards Vested During Current Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 2,089,351 | (83,661) | |
| Rintoul [Member] | Change In Fair Value As Of Vesting Date Of Prior Year Awards Vested During Current Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 675,793 | (145,001) | |
| Rintoul [Member] | Stock Award Values Reported in SCT for the Covered Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (1,170,960) | (765,850) | |
| Rintoul [Member] | Option Award Values Reported in SCT for the Covered Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (662,909) | (259,307) | |
| Non-PEO NEO [Member] | Year-end Fair Value Of Awards Granted In The Current Fiscal Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 331,139 | 442,880 | |
| Non-PEO NEO [Member] | Change In Fair Value Of Outstanding And Unvested Awards Granted In Prior Fiscal Years [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (10,251) | (1,126) | 5,333 |
| Non-PEO NEO [Member] | Change In Fair Value As Of Vesting Date Of Awards Vested During Current Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 617,144 | 213 | |
| Non-PEO NEO [Member] | Change In Fair Value As Of Vesting Date Of Prior Year Awards Vested During Current Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (6,934) | 108,379 | (26,400) |
| Non-PEO NEO [Member] | Stock Award Values Reported in SCT for the Covered Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (525,690) | (334,400) | (238,765) |
| Non-PEO NEO [Member] | Option Award Values Reported in SCT for the Covered Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | $ (228,750) | $ 194,973 | $ (80,843) |
