| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars in thousands) | |||||||||||
| Graphite Electrodes - LTAs | $ | 36,094\u00a0 | $ | 69,866\u00a0 | |||||||
| Graphite Electrodes - Non-LTAs | 87,893\u00a0 | 56,960\u00a0 | |||||||||
| By-products and other | 12,597\u00a0 | 11,976\u00a0 | |||||||||
| Total Revenues | $ | 136,584\u00a0 | $ | 138,802\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| (Dollars in thousands) | |||||||||||
| Current deferred revenue | $ | 23,695\u00a0 | $ | 31,583\u00a0 |
| 2024 | |||||
| (Dollars in millions) | |||||
| Estimated LTA revenue | $100-$135(1) |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars in thousands) | |||||||||||
| Graphite Electrodes - LTAs | $ | 36,094\u00a0 | $ | 69,866\u00a0 | |||||||
| Graphite Electrodes - Non-LTAs | 87,893\u00a0 | 56,960\u00a0 | |||||||||
| By-products and other | 12,597\u00a0 | 11,976\u00a0 | |||||||||
| Total Revenues | $ | 136,584\u00a0 | $ | 138,802\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| (Dollars in thousands) | |||||||||||
| Current deferred revenue | $ | 23,695\u00a0 | $ | 31,583\u00a0 |
| 2024 | |||||
| (Dollars in millions) | |||||
| Estimated LTA revenue | $100-$135(1) |
| \u00a0 | March 31, 2024 | December 31, 2023 | |||||||||||||||||||||||||||||||||
| Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | ||||||||||||||||||||||||||||||
| (Dollars in thousands) | |||||||||||||||||||||||||||||||||||
| Trade names | $ | 22,500\u00a0 | $ | (17,597) | $ | 4,903\u00a0 | $ | 22,500\u00a0 | $ | (17,379) | $ | 5,121\u00a0 | |||||||||||||||||||||||
| Technology and know-how | 55,300\u00a0 | (46,511) | 8,789\u00a0 | 55,300\u00a0 | (45,746) | 9,554\u00a0 | |||||||||||||||||||||||||||||
| Customer-related intangibles | 64,500\u00a0 | (37,870) | 26,630\u00a0 | 64,500\u00a0 | (36,802) | 27,698\u00a0 | |||||||||||||||||||||||||||||
| Total finite-lived intangible assets | $ | 142,300\u00a0 | $ | (101,978) | $ | 40,322\u00a0 | $ | 142,300\u00a0 | $ | (99,927) | $ | 42,373\u00a0 |
| \u00a0 | March 31, 2024 | December 31, 2023 | |||||||||||||||||||||||||||||||||
| Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | ||||||||||||||||||||||||||||||
| (Dollars in thousands) | |||||||||||||||||||||||||||||||||||
| Trade names | $ | 22,500\u00a0 | $ | (17,597) | $ | 4,903\u00a0 | $ | 22,500\u00a0 | $ | (17,379) | $ | 5,121\u00a0 | |||||||||||||||||||||||
| Technology and know-how | 55,300\u00a0 | (46,511) | 8,789\u00a0 | 55,300\u00a0 | (45,746) | 9,554\u00a0 | |||||||||||||||||||||||||||||
| Customer-related intangibles | 64,500\u00a0 | (37,870) | 26,630\u00a0 | 64,500\u00a0 | (36,802) | 27,698\u00a0 | |||||||||||||||||||||||||||||
| Total finite-lived intangible assets | $ | 142,300\u00a0 | $ | (101,978) | $ | 40,322\u00a0 | $ | 142,300\u00a0 | $ | (99,927) | $ | 42,373\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| 2020 Senior Secured Notes | 500,000\u00a0 | 500,000\u00a0 | |||||||||
| 2023 Senior Secured Notes | 450,000\u00a0 | 450,000\u00a0 | |||||||||
| Other debt | 136\u00a0 | 139\u00a0 | |||||||||
| Unamortized debt discount and issuance costs | (23,225) | (24,494) | |||||||||
| Total debt | 926,911\u00a0 | 925,645\u00a0 | |||||||||
| Less: Long-term debt, current portion | (132) | (134) | |||||||||
| Long-term debt | $ | 926,779\u00a0 | $ | 925,511\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| 2020 Senior Secured Notes | 500,000\u00a0 | 500,000\u00a0 | |||||||||
| 2023 Senior Secured Notes | 450,000\u00a0 | 450,000\u00a0 | |||||||||
| Other debt | 136\u00a0 | 139\u00a0 | |||||||||
| Unamortized debt discount and issuance costs | (23,225) | (24,494) | |||||||||
| Total debt | 926,911\u00a0 | 925,645\u00a0 | |||||||||
| Less: Long-term debt, current portion | (132) | (134) | |||||||||
| Long-term debt | $ | 926,779\u00a0 | $ | 925,511\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| Inventories: | |||||||||||
| Raw materials and supplies | $ | 86,004\u00a0 | $ | 109,084\u00a0 | |||||||
| Work in process | 181,977\u00a0 | 186,473\u00a0 | |||||||||
| Finished goods | 34,892\u00a0 | 34,589\u00a0 | |||||||||
| \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Total | $ | 302,873\u00a0 | $ | 330,146\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| Inventories: | |||||||||||
| Raw materials and supplies | $ | 86,004\u00a0 | $ | 109,084\u00a0 | |||||||
| Work in process | 181,977\u00a0 | 186,473\u00a0 | |||||||||
| Finished goods | 34,892\u00a0 | 34,589\u00a0 | |||||||||
| \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Total | $ | 302,873\u00a0 | $ | 330,146\u00a0 |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Interest incurred on debt | $ | 17,095\u00a0 | $ | 10,622\u00a0 | |||||||
| Accretion of original issue discount | 520\u00a0 | 168\u00a0 | |||||||||
| Amortization of debt issuance costs | 748\u00a0 | 655\u00a0 | |||||||||
| Amortization of interest rate swap deferred gains | (2,737) | \u2014\u00a0 | |||||||||
| Unrealized mark-to-market loss on de-designated interest rate swap | \u2014\u00a0 | 1,361\u00a0 | |||||||||
| Total interest expense | $ | 15,626\u00a0 | $ | 12,806\u00a0 |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Interest incurred on debt | $ | 17,095\u00a0 | $ | 10,622\u00a0 | |||||||
| Accretion of original issue discount | 520\u00a0 | 168\u00a0 | |||||||||
| Amortization of debt issuance costs | 748\u00a0 | 655\u00a0 | |||||||||
| Amortization of interest rate swap deferred gains | (2,737) | \u2014\u00a0 | |||||||||
| Unrealized mark-to-market loss on de-designated interest rate swap | \u2014\u00a0 | 1,361\u00a0 | |||||||||
| Total interest expense | $ | 15,626\u00a0 | $ | 12,806\u00a0 |
(Dollars in thousands) | |||||
| Balance as of December 31, 2023 | $ | 77\u00a0 | |||
| Product warranty charges/adjustments | 144\u00a0 | ||||
| Payments and settlements | (1) | ||||
| Balance as of March 31, 2024 | $ | 220\u00a0 |
(Dollars in thousands) | |||||
| Balance as of December 31, 2023 | $ | 77\u00a0 | |||
| Product warranty charges/adjustments | 144\u00a0 | ||||
| Payments and settlements | (1) | ||||
| Balance as of March 31, 2024 | $ | 220\u00a0 |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||
| Benefit for income taxes | $ | (4,201) | $ | (2,904) | |||||||
| Pre-tax loss | (35,070) | (10,273) | |||||||||
| Effective tax rate | 12.0\u00a0 | % | 28.3\u00a0 | % |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||
| Benefit for income taxes | $ | (4,201) | $ | (2,904) | |||||||
| Pre-tax loss | (35,070) | (10,273) | |||||||||
| Effective tax rate | 12.0\u00a0 | % | 28.3\u00a0 | % |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | Notional Amount | Notional Amount | |||||||||
| (Dollars in thousands) | |||||||||||
| Derivative instruments designated as hedges: | |||||||||||
| Foreign currency derivatives | $ | \u2014\u00a0 | $ | 10,684\u00a0 | |||||||
| Derivative instruments not designated as hedges: | |||||||||||
| Foreign currency derivatives | $ | 21,953\u00a0 | $ | 41,863\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | \u00a0\u00a0\u00a0Fair\u00a0Value | \u00a0\u00a0\u00a0Fair\u00a0Value | |||||||||
| (Dollars in thousands) | |||||||||||
| Prepaid and other current assets | |||||||||||
| Foreign currency derivatives | $ | \u2014\u00a0 | $ | 386\u00a0 | |||||||
| Total | $ | \u2014\u00a0 | $ | 386\u00a0 | |||||||
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||
| Location of Realized (Gain)/Loss Recognized in the Condensed Consolidated Statement of Operations | Three Months Ended March 31, | |||||||||||||||||||
| 2024 | 2023 | |||||||||||||||||||
| Derivatives designated as cash flow hedges: | (Dollars in thousands) | |||||||||||||||||||
| Foreign currency derivatives | Cost of goods sold | $ | (68) | $ | 2,040\u00a0 | |||||||||||||||
| Commodity derivative contracts | Cost of goods sold | (2,462) | (2,817) | |||||||||||||||||
| Interest rate swap contracts | Interest expense | (2,737) | (2,445) | |||||||||||||||||
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||
| Location of (Gain)/Loss Recognized in the Condensed Consolidated Statement of Operations | Three Months Ended March 31, | |||||||||||||||||||
| 2024 | 2023 | |||||||||||||||||||
| Derivatives not designated as hedges: | (Dollars in thousands) | |||||||||||||||||||
| Foreign currency derivatives | Cost of goods sold, other expense (income), net | $ | 127\u00a0 | $ | 436\u00a0 | |||||||||||||||
| Interest rate swap contracts | Interest expense | \u2014\u00a0 | 1,361\u00a0 | |||||||||||||||||
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | \u00a0\u00a0\u00a0Fair\u00a0Value | \u00a0\u00a0\u00a0Fair\u00a0Value | |||||||||
| (Dollars in thousands) | |||||||||||
| Prepaid and other current assets | |||||||||||
| Foreign currency derivatives | 232\u00a0 | 244\u00a0 | |||||||||
| Other accrued liabilities | |||||||||||
| Foreign currency derivatives | (133) | (519) | |||||||||
| Net liability | $ | 99\u00a0 | $ | (275) |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | Notional Amount | Notional Amount | |||||||||
| (Dollars in thousands) | |||||||||||
| Derivative instruments designated as hedges: | |||||||||||
| Foreign currency derivatives | $ | \u2014\u00a0 | $ | 10,684\u00a0 | |||||||
| Derivative instruments not designated as hedges: | |||||||||||
| Foreign currency derivatives | $ | 21,953\u00a0 | $ | 41,863\u00a0 |
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | \u00a0\u00a0\u00a0Fair\u00a0Value | \u00a0\u00a0\u00a0Fair\u00a0Value | |||||||||
| (Dollars in thousands) | |||||||||||
| Prepaid and other current assets | |||||||||||
| Foreign currency derivatives | $ | \u2014\u00a0 | $ | 386\u00a0 | |||||||
| Total | $ | \u2014\u00a0 | $ | 386\u00a0 | |||||||
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||
| Location of Realized (Gain)/Loss Recognized in the Condensed Consolidated Statement of Operations | Three Months Ended March 31, | |||||||||||||||||||
| 2024 | 2023 | |||||||||||||||||||
| Derivatives designated as cash flow hedges: | (Dollars in thousands) | |||||||||||||||||||
| Foreign currency derivatives | Cost of goods sold | $ | (68) | $ | 2,040\u00a0 | |||||||||||||||
| Commodity derivative contracts | Cost of goods sold | (2,462) | (2,817) | |||||||||||||||||
| Interest rate swap contracts | Interest expense | (2,737) | (2,445) | |||||||||||||||||
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||
| Location of (Gain)/Loss Recognized in the Condensed Consolidated Statement of Operations | Three Months Ended March 31, | |||||||||||||||||||
| 2024 | 2023 | |||||||||||||||||||
| Derivatives not designated as hedges: | (Dollars in thousands) | |||||||||||||||||||
| Foreign currency derivatives | Cost of goods sold, other expense (income), net | $ | 127\u00a0 | $ | 436\u00a0 | |||||||||||||||
| Interest rate swap contracts | Interest expense | \u2014\u00a0 | 1,361\u00a0 | |||||||||||||||||
| March 31, 2024 | December 31, 2023 | ||||||||||
| \u00a0 | \u00a0\u00a0\u00a0Fair\u00a0Value | \u00a0\u00a0\u00a0Fair\u00a0Value | |||||||||
| (Dollars in thousands) | |||||||||||
| Prepaid and other current assets | |||||||||||
| Foreign currency derivatives | 232\u00a0 | 244\u00a0 | |||||||||
| Other accrued liabilities | |||||||||||
| Foreign currency derivatives | (133) | (519) | |||||||||
| Net liability | $ | 99\u00a0 | $ | (275) |
| \u00a0 | March 31, 2024 | December 31, 2023 | |||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Foreign currency translation adjustments, net of tax | $ | (25,660) | $ | (19,188) | |||||||
| Commodity, interest rate, and foreign currency derivatives, net of tax | 3,477\u00a0 | 7,730\u00a0 | |||||||||
| Total accumulated other comprehensive loss | $ | (22,183) | $ | (11,458) |
| \u00a0 | March 31, 2024 | December 31, 2023 | |||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Foreign currency translation adjustments, net of tax | $ | (25,660) | $ | (19,188) | |||||||
| Commodity, interest rate, and foreign currency derivatives, net of tax | 3,477\u00a0 | 7,730\u00a0 | |||||||||
| Total accumulated other comprehensive loss | $ | (22,183) | $ | (11,458) |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars\u00a0in\u00a0thousands, except per share amounts) | |||||||||||
| Numerator for basic and diluted loss per share: | |||||||||||
| Net loss | $ | (30,869) | $ | (7,369) | |||||||
| Denominator: | |||||||||||
| Weighted average common shares outstanding for basic calculation | 257,399,365\u00a0 | 256,974,904\u00a0 | |||||||||
| Add: Effect of equity awards | \u2014\u00a0 | \u2014\u00a0 | |||||||||
| Weighted average common shares outstanding for diluted calculation | 257,399,365\u00a0 | 256,974,904\u00a0 | |||||||||
| Basic loss per share | $ | (0.12) | $ | (0.03) | |||||||
| Diluted loss per share | $ | (0.12) | $ | (0.03) |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars\u00a0in\u00a0thousands, except per share amounts) | |||||||||||
| Numerator for basic and diluted loss per share: | |||||||||||
| Net loss | $ | (30,869) | $ | (7,369) | |||||||
| Denominator: | |||||||||||
| Weighted average common shares outstanding for basic calculation | 257,399,365\u00a0 | 256,974,904\u00a0 | |||||||||
| Add: Effect of equity awards | \u2014\u00a0 | \u2014\u00a0 | |||||||||
| Weighted average common shares outstanding for diluted calculation | 257,399,365\u00a0 | 256,974,904\u00a0 | |||||||||
| Basic loss per share | $ | (0.12) | $ | (0.03) | |||||||
| Diluted loss per share | $ | (0.12) | $ | (0.03) |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||
| Recorded in Cost of Goods Sold | |||||||||||
| Inventory write-offs | $ | 2,202\u00a0 | $ | \u2014\u00a0 | |||||||
| Fixed asset write-offs | 453\u00a0 | \u2014\u00a0 | |||||||||
| Total rationalization-related expenses | $ | 2,655\u00a0 | $ | \u2014\u00a0 | |||||||
| Recorded in Rationalization Expenses | |||||||||||
| Severance and related costs | $ | 2,878\u00a0 | $ | \u2014\u00a0 | |||||||
| Contract terminations | 267\u00a0 | \u2014\u00a0 | |||||||||
| Total rationalization expenses | $ | 3,145\u00a0 | $ | \u2014\u00a0 |
| Balance Sheet Line Item | |||||||||||
| Other Accrued Liabilities | Other Long-Term Obligations | ||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||
| Balance as of December 31, 2023 | $ | \u2014\u00a0 | $ | \u2014\u00a0 | |||||||
| Charges incurred | 2,543\u00a0 | 602\u00a0 | |||||||||
| Payments and settlements | (363) | \u2014\u00a0 | |||||||||
| Balance as of March 31, 2024 | $ | 2,180\u00a0 | $ | 602\u00a0 |
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||
| Recorded in Cost of Goods Sold | |||||||||||
| Inventory write-offs | $ | 2,202\u00a0 | $ | \u2014\u00a0 | |||||||
| Fixed asset write-offs | 453\u00a0 | \u2014\u00a0 | |||||||||
| Total rationalization-related expenses | $ | 2,655\u00a0 | $ | \u2014\u00a0 | |||||||
| Recorded in Rationalization Expenses | |||||||||||
| Severance and related costs | $ | 2,878\u00a0 | $ | \u2014\u00a0 | |||||||
| Contract terminations | 267\u00a0 | \u2014\u00a0 | |||||||||
| Total rationalization expenses | $ | 3,145\u00a0 | $ | \u2014\u00a0 |
| Balance Sheet Line Item | |||||||||||
| Other Accrued Liabilities | Other Long-Term Obligations | ||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||
| Balance as of December 31, 2023 | $ | \u2014\u00a0 | $ | \u2014\u00a0 | |||||||
| Charges incurred | 2,543\u00a0 | 602\u00a0 | |||||||||
| Payments and settlements | (363) | \u2014\u00a0 | |||||||||
| Balance as of March 31, 2024 | $ | 2,180\u00a0 | $ | 602\u00a0 |