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Business And Summary Of Significant Accounting Policies (Narrative) (Details) | Dec. 31, 2021 | May 31, 2021 | Dec. 31, 2020 | Dec. 05, 2019 $ / shares | Apr. 26, 2018 $ / shares shares
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Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |
Sale of Stock, Price Per Share | $ / shares |  |  |  | $ 13.125 | $ 15.00
Shares, Issued | shares |  |  |  |  | 38,097,525
Number of Major Product Categories | 2 |  |  |  |
GrafTech International Ltd [Member] | Brookfield [Member] |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |
Equity Method Investment, Ownership Percentage | 24.30% | 24.00% | 55.30% |  |

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