Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual amounts could differ from these estimates. Revenue Recognition The Company sells coke as well as steam and electricity and also provides mixing and/or handling services of coal and other aggregates. The Company also receives fees for operating the cokemaking plant in Brazil and for the licensing of its proprietary technology for use at this facility as well as reimbursement of substantially all of its operating costs. See Note 19. Cash Equivalents The Company considers all highly liquid investments with a remaining maturity of three months or less at the time of purchase to be cash equivalents. These cash equivalents consist principally of money market funds. Inventories Inventories are valued at the lower of cost or net realizable value. Cost is determined using the first-in, first-out method, except for the Company’s materials and supplies inventory, which are determined using the average-cost method. The Company primarily utilizes the selling prices under its long-term coke supply contracts to record lower of cost or net realizable value inventory adjustments. Properties, Plants and Equipment Plants and equipment are depreciated on a straight-line basis over their estimated useful lives. Coke and energy plant, machinery and equipment are generally depreciated over 25 to 30 years. Logistics plant and equipment are generally depreciated over 15 to 35 years. Depreciation and amortization is excluded from cost of products sold and operating expenses and is presented separately on the Consolidated Statements of Operations. Gains and losses on the disposal or retirement of fixed assets are reflected in earnings when the assets are sold or retired. Amounts incurred that extend an asset’s useful life, increase its productivity or add production capacity are capitalized. The Company accounts for changes in useful lives, when appropriate, as a change in estimate, with prospective application only. The Company capitalized interest of $0.2 million, $2.3 million, and $3.2 million in 2020, 2019 and 2018, respectively. Direct costs, such as outside labor, materials, internal payroll and benefits costs incurred during capital projects are capitalized; indirect costs are not capitalized. Normal repairs and maintenance costs are expensed as incurred. Goodwill Goodwill, which represents the excess of the purchase price over the fair value of net assets acquired, is tested for impairment as of October 1 of each year, or when events occur or circumstances change that would, more likely than not, reduce the fair value of a reporting unit to below its carrying value. The Company performs its annual goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount. The Company would recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. See Note 8. Intangible Assets Intangible assets are primarily comprised of permits. Intangible assets are amortized over their useful lives in a manner that reflects the pattern in which the economic benefit of the intangible asset is consumed. Intangible assets are assessed for impairment when a triggering event occurs. Impairment of Long-Lived Assets Long-lived assets, which includes intangible assets and properties, plants and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. A long-lived asset, or group of assets, is considered to be impaired when the undiscounted net cash flows expected to be generated by the asset are less than its carrying amount. Such estimated future cash flows are highly subjective and are based on numerous assumptions about future operations and market conditions. The impairment recognized is the amount by which the carrying amount exceeds the fair market value of the impaired asset, or group of assets. It is also difficult to precisely estimate fair market value because quoted market prices for our long-lived assets may not be readily available. Therefore, fair market value is generally based on the present values of estimated future cash flows using discount rates commensurate with the risks associated with the assets being reviewed for impairment. See Note 8. Income Taxes Deferred tax asset and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those differences are projected to be recovered or settled. The Company recognizes uncertain tax positions in its financial statements when minimum recognition threshold and measurement attributes are met in accordance with current accounting guidance. See Note 5. Black Lung Benefit Liabilities The Company has obligations related to coal workers’ pneumoconiosis, or black lung, benefits of certain of our former coal miners and their dependents. We adjust our liability each year based upon actuarial calculations of our expected future payments for these benefits, including a provision for incurred but not reported losses. See Note 13. Postretirement Benefit Plan Liabilities The postretirement benefit plans, which are frozen, are unfunded and the accumulated postretirement benefit obligation is fully recognized on the Consolidated Balance Sheets. Actuarial gains (losses) and prior service costs (benefits) which have not yet been recognized in net income are recognized as a credit (charge) to accumulated other comprehensive income (loss). The credit (charge) to accumulated other comprehensive income (loss), which is reflected net of related tax effects, is subsequently recognized in net income when amortized as a component of postretirement benefit plans expense included in interest expense, net on the Consolidated Statements of Operations. See Note 10. Asset Retirement Obligations The fair value of a liability for an asset retirement obligation is recognized in the period in which it is incurred if a reasonable estimate of fair value can be made. The associated asset retirement costs are capitalized as part of the carrying amount of the asset and depreciated over its remaining estimated useful life. When the assumptions used to estimate a recorded asset retirement obligation change, a revision is recorded to both the asset retirement obligation and the asset retirement cost capitalized to the extent remaining useful life exists. The Company’s asset retirement obligations primarily relate to costs associated with restoring land to its original state. See Note 9. Shipping and Handling Costs Shipping and handling costs are included in cost of products sold and operating expenses on the Consolidated Statements of Operations and are generally passed through to our customers. The Company has elected the practical expedient under Accounting Standards Codification ("ASC") 606, "Revenue from Contracts with Customers," to account for shipping and handling activities as a promise to fulfill the transfer of coke. Share-Based Compensation We measure the cost of employee services in exchange for equity instrument awards and cash awards based on the grant-date fair value of the award. Cash awards and the performance metrics of equity awards are remeasured on a quarterly basis. The market metrics of equity awards are not remeasured. The total cost is recognized over the requisite service period. Award forfeitures are accounted for as they occur. The costs of equity awards and cash awards are recorded to additional paid-in capital and accrued liabilities, respectively, on the Consolidated Balance Sheets. See Note 16. Fair Value Measurements The Company determines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As required, the Company utilizes valuation techniques that maximize the use of observable inputs (levels 1 and 2) and minimize the use of unobservable inputs (level 3) within the fair value hierarchy included in current accounting guidance. Assets and liabilities are classified within the fair value hierarchy based on the lowest level (least observable) input that is significant to the measurement in its entirety. See Note 18. Currency Translation The functional currency of the Company’s Brazilian operations is the Brazilian real. The Company’s Brazil operations translate its assets and liabilities into U.S. dollars at the current exchange rates in effect at the end of the fiscal period. The gains or losses that result from this process are shown as cumulative translation adjustments within accumulated other comprehensive loss in the Consolidated Balance Sheets. The revenue and expense accounts of foreign operations are translated into U.S. dollars at the average exchange rates during the period. Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, “Leases (Topic 842).” ASU 2016-02 requires leases to be recognized as assets and liabilities on the balance sheet for the rights and obligations created by all leases with terms of more than 12 months. Subsequently, the FASB has issued various ASUs to provide further clarification around certain aspects of ASC 842, “Leases.” We adopted the standard effective January 1, 2019 using the modified retrospective transition approach and elected not to adjust prior comparative periods. Upon adoption, the Company recognized right-of-use assets and lease liabilities of $5.1 million at January 1, 2019. See Note 14. In February 2018, the FASB issued ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The Company adopted this ASU in the first quarter 2018 and reclassified $1.1 million of deferred tax adjustments to accumulated other comprehensive income (loss) from retained earnings on the December 31, 2017 balance sheet for the tax effects resulting from the Tax Cuts and Jobs Act of 2017. Labor Concentrations As of December 31, 2020, we have approximately 841 employees in the U.S. Approximately 41 percent of our domestic employees, principally at our cokemaking operations, are represented by the United Steelworkers union under various contracts. Additionally, approximately 3 percent of our domestic employees are represented by the International Union of Operating Engineers. During 2020, the labor agreements at Granite City and Haverhill were renewed and will expire on September 1, 2023 and November 1, 2023, respectively. As of December 31, 2020, we have approximately 292 employees at the cokemaking facility in Vitória, Brazil, all of whom are represented by a union under a labor agreement. During 2020, the labor agreement at our Vitória, Brazil facility was renewed for an additional year, and it expires on November 30, 2021.

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual amounts could differ from these estimates.

The Company sells coke as well as steam and electricity and also provides mixing and/or handling services of coal and other aggregates. The Company also receives fees for operating the cokemaking plant in Brazil and for the licensing of its proprietary technology for use at this facility as well as reimbursement of substantially all of its operating costs. See Note 19.

Inventories are valued at the lower of cost or net realizable value. Cost is determined using the first-in, first-out method, except for the Company’s materials and supplies inventory, which are determined using the average-cost method. The Company primarily utilizes the selling prices under its long-term coke supply contracts to record lower of cost or net realizable value inventory adjustments.

Plants and equipment are depreciated on a straight-line basis over their estimated useful lives. Coke and energy plant, machinery and equipment are generally depreciated over 25 to 30 years. Logistics plant and equipment are generally depreciated over 15 to 35 years. Depreciation and amortization is excluded from cost of products sold and operating expenses and is presented separately on the Consolidated Statements of Operations. Gains and losses on the disposal or retirement of fixed assets are reflected in earnings when the assets are sold or retired. Amounts incurred that extend an asset’s useful life, increase its productivity or add production capacity are capitalized. The Company accounts for changes in useful lives, when appropriate, as a change in estimate, with prospective application only. The Company capitalized interest of $0.2 million, $2.3 million, and $3.2 million in 2020, 2019 and 2018, respectively. Direct costs, such as outside labor, materials, internal payroll and benefits costs incurred during capital projects are capitalized; indirect costs are not capitalized. Normal repairs and maintenance costs are expensed as incurred.

Goodwill, which represents the excess of the purchase price over the fair value of net assets acquired, is tested for impairment as of October 1 of each year, or when events occur or circumstances change that would, more likely than not, reduce the fair value of a reporting unit to below its carrying value. The Company performs its annual goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount. The Company would recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. See Note 8.

Intangible assets are primarily comprised of permits. Intangible assets are amortized over their useful lives in a manner that reflects the pattern in which the economic benefit of the intangible asset is consumed. Intangible assets are assessed for impairment when a triggering event occurs.

Long-lived assets, which includes intangible assets and properties, plants and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. A long-lived asset, or group of assets, is considered to be impaired when the undiscounted net cash flows expected to be generated by the asset are less than its carrying amount. Such estimated future cash flows are highly subjective and are based on numerous assumptions about future operations and market conditions. The impairment recognized is the amount by which the carrying amount exceeds the fair market value of the impaired asset, or group of assets. It is also difficult to precisely estimate fair market value because quoted market prices for our long-lived assets may not be readily available. Therefore, fair market value is generally based on the present values of estimated future cash flows using discount rates commensurate with the risks associated with the assets being reviewed for impairment. See Note 8.

Deferred tax asset and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those differences are projected to be recovered or settled. The Company recognizes uncertain tax positions in its financial statements when minimum recognition threshold and measurement attributes are met in accordance with current accounting guidance. See Note 5.

The Company has obligations related to coal workers’ pneumoconiosis, or black lung, benefits of certain of our former coal miners and their dependents. We adjust our liability each year based upon actuarial calculations of our expected future payments for these benefits, including a provision for incurred but not reported losses. See Note 13.

The postretirement benefit plans, which are frozen, are unfunded and the accumulated postretirement benefit obligation is fully recognized on the Consolidated Balance Sheets. Actuarial gains (losses) and prior service costs (benefits) which have not yet been recognized in net income are recognized as a credit (charge) to accumulated other comprehensive income (loss). The credit (charge) to accumulated other comprehensive income (loss), which is reflected net of related tax effects, is subsequently recognized in net income when amortized as a component of postretirement benefit plans expense included in interest expense, net on the Consolidated Statements of Operations. See Note 10.

The fair value of a liability for an asset retirement obligation is recognized in the period in which it is incurred if a reasonable estimate of fair value can be made. The associated asset retirement costs are capitalized as part of the carrying amount of the asset and depreciated over its remaining estimated useful life. When the assumptions used to estimate a recorded asset retirement obligation change, a revision is recorded to both the asset retirement obligation and the asset retirement cost capitalized to the extent remaining useful life exists. The Company’s asset retirement obligations primarily relate to costs associated with restoring land to its original state. See Note 9.

Shipping and handling costs are included in cost of products sold and operating expenses on the Consolidated Statements of Operations and are generally passed through to our customers. The Company has elected the practical expedient under Accounting Standards Codification ("ASC") 606, "Revenue from Contracts with Customers," to account for shipping and handling activities as a promise to fulfill the transfer of coke.

We measure the cost of employee services in exchange for equity instrument awards and cash awards based on the grant-date fair value of the award. Cash awards and the performance metrics of equity awards are remeasured on a quarterly basis. The market metrics of equity awards are not remeasured. The total cost is recognized over the requisite service period. Award forfeitures are accounted for as they occur. The costs of equity awards and cash awards are recorded to additional paid-in capital and accrued liabilities, respectively, on the Consolidated Balance Sheets. See Note 16.

The Company determines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As required, the Company utilizes valuation techniques that maximize the use of observable inputs (levels 1 and 2) and minimize the use of unobservable inputs (level 3) within the fair value hierarchy included in current accounting guidance. Assets and liabilities are classified within the fair value hierarchy based on the lowest level (least observable) input that is significant to the measurement in its entirety. See Note 18.

The functional currency of the Company’s Brazilian operations is the Brazilian real. The Company’s Brazil operations translate its assets and liabilities into U.S. dollars at the current exchange rates in effect at the end of the fiscal period. The gains or losses that result from this process are shown as cumulative translation adjustments within accumulated other comprehensive loss in the Consolidated Balance Sheets. The revenue and expense accounts of foreign operations are translated into U.S. dollars at the average exchange rates during the period.

In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, “Leases (Topic 842).” ASU 2016-02 requires leases to be recognized as assets and liabilities on the balance sheet for the rights and obligations created by all leases with terms of more than 12 months. Subsequently, the FASB has issued various ASUs to provide further clarification around certain aspects of ASC 842, “Leases.” We adopted the standard effective January 1, 2019 using the modified retrospective transition approach and elected not to adjust prior comparative periods. Upon adoption, the Company recognized right-of-use assets and lease liabilities of $5.1 million at January 1, 2019. See Note 14.

In February 2018, the FASB issued ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The Company adopted this ASU in the first quarter 2018 and reclassified $1.1 million of deferred tax adjustments to accumulated other comprehensive income (loss) from retained earnings on the December 31, 2017 balance sheet for the tax effects resulting from the Tax Cuts and Jobs Act of 2017.

As of December 31, 2020, we have approximately 841 employees in the U.S. Approximately 41 percent of our domestic employees, principally at our cokemaking operations, are represented by the United Steelworkers union under various contracts. Additionally, approximately 3 percent of our domestic employees are represented by the International Union of Operating Engineers. During 2020, the labor agreements at Granite City and Haverhill were renewed and will expire on September 1, 2023 and November 1, 2023, respectively.

As of December 31, 2020, we have approximately 292 employees at the cokemaking facility in Vitória, Brazil, all of whom are represented by a union under a labor agreement. During 2020, the labor agreement at our Vitória, Brazil facility was renewed for an additional year, and it expires on November 30, 2021.