| Cover | Nov. 18, 2022 |
| Cover [Abstract] | |
| Entity Incorporation, State or Country Code | DE |
| Document Type | 8-K |
| Document Period End Date | Nov. 18, 2022 |
| Entity Registrant Name | GRAFTECH INTERNATIONAL LTD. |
| Entity File Number | 1-13888 |
| Entity Tax Identification Number | 27-2496053 |
| Entity Address, Address Line One | 982 Keynote Circle |
| Entity Address, City or Town | Brooklyn Heights |
| Entity Address, State or Province | OH |
| Entity Address, Postal Zip Code | 44131 |
| City Area Code | 216 |
| Local Phone Number | 676-2000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of each class | Common stock, $0.01 par value per share |
| Trading Symbol(s) | EAF |
| Name of each exchange on which registered | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000931148 |
| Amendment Flag | false |
