Organization And Summary Of Significant Accounting Policies	9 Months Ended
Sep. 30, 2019
Accounting Policies [Abstract]
Organization And Summary Of Significant Accounting Policies	Organization and Summary of Significant Accounting Policies A. Organization GrafTech International Ltd. (the “Company”) is a leading manufacturer of high quality graphite electrode products essential to the production of electric arc furnace ("EAF") steel and other ferrous and non-ferrous metals. References herein to “we,” “our,” or “us” refer collectively to GrafTech International Ltd. and its subsidiaries. On August 15, 2015, we became an indirect wholly owned subsidiary of Brookfield Asset Management Inc. (together with its affiliates, “Brookfield”) through a tender offer to our former stockholders and subsequent merger transaction. On April 23, 2018, the Company completed its initial public offering ("IPO"). The Company’s only reportable segment, Industrial Materials, is comprised of our two major product categories: graphite electrodes and petroleum needle coke products. Needle coke is the key raw material used in the production of graphite electrodes. The Company's vision is to provide highly engineered graphite electrode services, solutions and products to EAF operators. B. Basis of Presentation The interim condensed consolidated financial statements are unaudited; however, in the opinion of management, they have been prepared in accordance with Rule 10-01 of Regulation S-X and in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The December 31, 2018 financial position data included herein was derived from the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018 ("Annual Report on Form 10-K") filed on February 22, 2019 but does not include all disclosures required by GAAP in audited financial statements. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements, including the accompanying notes, contained in our Annual Report on Form 10-K filed on February 22, 2019. The unaudited condensed consolidated financial statements reflect all adjustments (all of which are of a normal, recurring nature) which management considers necessary for a fair statement of financial position, results of operations, comprehensive income and cash flows for the interim periods presented. The results for the interim periods are not necessarily indicative of results which may be expected for any other interim period or for the full year. Earnings per share The calculation of basic earnings per share is based on the number of common shares outstanding after giving effect to the stock split effected on April 12, 2018 and the common stock repurchases on August 13, 2018 and during the third quarter of 2019. Diluted earnings per share recognizes the dilution that would occur if stock options, deferred stock units or restricted stock units were exercised or converted into common shares. See Note 13 "Earnings Per Share". C. New Accounting Standards Recently Adopted Accounting Standards In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). Under this new guidance, a company will now recognize most leases on its balance sheet as lease liabilities with corresponding right-of-use assets. This ASU is effective for fiscal years beginning after December 15, 2018. The Company adopted ASU No. 2016-02 on January 1, 2019. The adoption impact was not material to our financial position, results of operations or cash flows. See Note 3 "Leases" for information regarding this standard and its adoption. Accounting Standards Not Yet Adopted In January 2017, the FASB issued ASU No. 2017‑04, Intangibles‑Goodwill and Other (Topic 350). This guidance was issued to simplify the accounting for goodwill impairment. The guidance removes the second step of the goodwill impairment test, which requires that a hypothetical purchase price allocation be performed to determine the amount of impairment, if any. Under this new guidance, a goodwill impairment charge will be based on the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The guidance will become effective on a prospective basis for the Company on January 1, 2020 with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standard is not expected to have a material effect on the Company’s financial position, results of operations or cash flows. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments–Credit Losses (Topic 326), which introduces the Current Expected Credit Losses ("CECL") accounting model. CECL requires earlier recognition of credit losses, while also providing additional transparency about credit risk. CECL utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses at the time the financial asset is originated or acquired. The expected credit losses are adjusted each period for changes in expected lifetime credit losses. ASU No. 2016-13 is effective for the the Company on January 1, 2020. The Company is currently evaluating the impact of this standard.

Organization and Summary of Significant Accounting Policies

A. Organization

GrafTech International Ltd. (the “Company”) is a leading manufacturer of high quality graphite electrode products essential to the production of electric arc furnace ("EAF") steel and other ferrous and non-ferrous metals. References herein to “we,” “our,” or “us” refer collectively to GrafTech International Ltd. and its subsidiaries. On August 15, 2015, we became an indirect wholly owned subsidiary of Brookfield Asset Management Inc. (together with its affiliates, “Brookfield”) through a tender offer to our former stockholders and subsequent merger transaction. On April 23, 2018, the Company completed its initial public offering ("IPO").

The Company’s only reportable segment, Industrial Materials, is comprised of our two major product categories: graphite electrodes and petroleum needle coke products. Needle coke is the key raw material used in the production of graphite electrodes. The Company's vision is to provide highly engineered graphite electrode services, solutions and products to EAF operators.

B. Basis of Presentation

The interim condensed consolidated financial statements are unaudited; however, in the opinion of management, they have been prepared in accordance with Rule 10-01 of Regulation S-X and in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The December 31, 2018 financial position data included herein was derived from the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018 ("Annual Report on Form 10-K") filed on February 22, 2019 but does not include all disclosures required by GAAP in audited financial statements. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements, including the accompanying notes, contained in our Annual Report on Form 10-K filed on February 22, 2019.

The unaudited condensed consolidated financial statements reflect all adjustments (all of which are of a normal, recurring nature) which management considers necessary for a fair statement of financial position, results of operations, comprehensive income and cash flows for the interim periods presented. The results for the interim periods are not necessarily indicative of results which may be expected for any other interim period or for the full year.

Earnings per share

The calculation of basic earnings per share is based on the number of common shares outstanding after giving effect to the stock split effected on April 12, 2018 and the common stock repurchases on August 13, 2018 and during the third quarter of 2019. Diluted earnings per share recognizes the dilution that would occur if stock options, deferred stock units or restricted stock units were exercised or converted into common shares. See Note 13 "Earnings Per Share".

C. New Accounting Standards

Recently Adopted Accounting Standards

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). Under this new guidance, a company will now recognize most leases on its balance sheet as lease liabilities with corresponding right-of-use assets. This ASU is effective for fiscal years beginning after December 15, 2018. The Company adopted ASU No. 2016-02 on January 1, 2019. The adoption impact was not material to our financial position, results of operations or cash flows. See Note 3 "Leases" for information regarding this standard and its adoption.

Accounting Standards Not Yet Adopted

In January 2017, the FASB issued ASU No. 2017‑04, Intangibles‑Goodwill and Other (Topic 350). This guidance was issued to simplify the accounting for goodwill impairment. The guidance removes the second step of the goodwill impairment test, which requires that a hypothetical purchase price allocation be performed to determine the amount of impairment, if any. Under this new guidance, a goodwill impairment charge will be based on the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The guidance will become effective on a prospective basis for the Company on January 1, 2020 with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standard is not expected to have a material effect on the Company’s financial position, results of operations or cash flows.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments–Credit Losses (Topic 326), which introduces the Current Expected Credit Losses ("CECL") accounting model. CECL requires earlier recognition of credit losses, while also providing additional transparency about credit risk. CECL utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses at the time the financial asset is originated or acquired. The expected credit losses are adjusted each period for changes in expected lifetime credit losses. ASU No. 2016-13 is effective for the the Company on January 1, 2020. The Company is currently evaluating the impact of this standard.