| \u00a0 | Years | ||||
| Buildings | 25-40 | ||||
| Land improvements | 20 | ||||
| Machinery and equipment | 5-20 | ||||
| Furniture and fixtures | 5-10 |
| \u00a0 | Years | ||||
| Trade name | 5-20 | ||||
| Technology and know-how | 5-14 | ||||
| Customer related intangible | 5-15 |
| \u00a0 | Years | ||||
| Buildings | 25-40 | ||||
| Land improvements | 20 | ||||
| Machinery and equipment | 5-20 | ||||
| Furniture and fixtures | 5-10 |
| \u00a0 | Years | ||||
| Buildings | 25-40 | ||||
| Land improvements | 20 | ||||
| Machinery and equipment | 5-20 | ||||
| Furniture and fixtures | 5-10 |
| \u00a0 | Years | ||||
| Trade name | 5-20 | ||||
| Technology and know-how | 5-14 | ||||
| Customer related intangible | 5-15 |
| \u00a0 | Years | ||||
| Trade name | 5-20 | ||||
| Technology and know-how | 5-14 | ||||
| Customer related intangible | 5-15 |
| For the Year Ended December 31, | |||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||
| (Dollars in thousands) | |||||||||||||||||
| Graphite Electrodes - Long-term agreements | $ | 1,069,772\u00a0 | $ | 1,437,354\u00a0 | $ | 1,341,557\u00a0 | |||||||||||
| Graphite Electrodes - Short-term agreements and spot sales | 123,845\u00a0 | 260,979\u00a0 | 395,928\u00a0 | ||||||||||||||
| By-products and other | 30,744\u00a0 | 92,460\u00a0 | 158,425\u00a0 | ||||||||||||||
| Total Revenues | $ | 1,224,361\u00a0 | $ | 1,790,793\u00a0 | $ | 1,895,910\u00a0 |
| Current deferred revenue | Long-Term deferred revenue | ||||||||||
| (Dollars in thousands) | |||||||||||
| Balance as of December 31, 2018 | $ | 5,380\u00a0 | $ | 7,716\u00a0 | |||||||
| Increases due to cash received | 7,961\u00a0 | \u2014\u00a0 | |||||||||
| Revenue recognized | (4,678) | \u2014\u00a0 | |||||||||
| Revision of estimates | \u2014\u00a0 | (694) | |||||||||
| Reclassification between long-term and current | 3,042\u00a0 | (3,042) | |||||||||
| Foreign currency impact | 71\u00a0 | (122) | |||||||||
| Balance as of December 31, 2019 | 11,776\u00a0 | 3,858\u00a0 | |||||||||
| Increases due to cash received | 10,110\u00a0 | \u2014\u00a0 | |||||||||
| Revenue recognized | (6,270) | \u2014\u00a0 | |||||||||
| Reclassification between long-term and current | (1,804) | 1,804\u00a0 | |||||||||
| Foreign currency impact | (756) | \u2014\u00a0 | |||||||||
| Balance as of December 31, 2020 | $ | 13,056\u00a0 | $ | 5,662\u00a0 |
| 2021 | 2022 | 2023 through 2024 | |||||||||||||||
| (Dollars in millions) | |||||||||||||||||
| Estimated LTA revenue | $925-$1,025 | $910-$1,010 | $350-$450(1) |
| For the Year Ended December 31, | |||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||
| (Dollars in thousands) | |||||||||||||||||
| Graphite Electrodes - Long-term agreements | $ | 1,069,772\u00a0 | $ | 1,437,354\u00a0 | $ | 1,341,557\u00a0 | |||||||||||
| Graphite Electrodes - Short-term agreements and spot sales | 123,845\u00a0 | 260,979\u00a0 | 395,928\u00a0 | ||||||||||||||
| By-products and other | 30,744\u00a0 | 92,460\u00a0 | 158,425\u00a0 | ||||||||||||||
| Total Revenues | $ | 1,224,361\u00a0 | $ | 1,790,793\u00a0 | $ | 1,895,910\u00a0 |
| Current deferred revenue | Long-Term deferred revenue | ||||||||||
| (Dollars in thousands) | |||||||||||
| Balance as of December 31, 2018 | $ | 5,380\u00a0 | $ | 7,716\u00a0 | |||||||
| Increases due to cash received | 7,961\u00a0 | \u2014\u00a0 | |||||||||
| Revenue recognized | (4,678) | \u2014\u00a0 | |||||||||
| Revision of estimates | \u2014\u00a0 | (694) | |||||||||
| Reclassification between long-term and current | 3,042\u00a0 | (3,042) | |||||||||
| Foreign currency impact | 71\u00a0 | (122) | |||||||||
| Balance as of December 31, 2019 | 11,776\u00a0 | 3,858\u00a0 | |||||||||
| Increases due to cash received | 10,110\u00a0 | \u2014\u00a0 | |||||||||
| Revenue recognized | (6,270) | \u2014\u00a0 | |||||||||
| Reclassification between long-term and current | (1,804) | 1,804\u00a0 | |||||||||
| Foreign currency impact | (756) | \u2014\u00a0 | |||||||||
| Balance as of December 31, 2020 | $ | 13,056\u00a0 | $ | 5,662\u00a0 |
| 2021 | 2022 | 2023 through 2024 | |||||||||||||||
| (Dollars in millions) | |||||||||||||||||
| Estimated LTA revenue | $925-$1,025 | $910-$1,010 | $350-$450(1) |
| 2020 | 2019 | 2018 | |||||||||||||||
| Award type: | |||||||||||||||||
| \u00a0\u00a0\u00a0\u00a0Stock options | 308,875\u00a0 | 229,250\u00a0 | 979,790\u00a0 | ||||||||||||||
| \u00a0\u00a0\u00a0\u00a0Deferred share units | 58,207\u00a0 | 31,829\u00a0 | 42,243\u00a0 | ||||||||||||||
| \u00a0\u00a0\u00a0\u00a0Restricted stock units | 334,062\u00a0 | 260,640\u00a0 | 6,740\u00a0 |
| Number of Shares | Weighted- Average Grant Date Fair Value | |||||||||||||
| Outstanding unvested as of December 31, 2019 | 282,716\u00a0 | $ | 12.83\u00a0 | |||||||||||
| \u00a0\u00a0\u00a0\u00a0Granted | 392,269\u00a0 | 8.84\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Cancelled | (45,760) | 12.24\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Vested | (104,737) | 10.30\u00a0 | ||||||||||||
| Outstanding unvested as of December 31, 2020 | 524,488\u00a0 | $ | 10.41\u00a0 |
| For the Year Ended December\u00a031,2020 | For the Year Ended December\u00a031,2019 | For the Year Ended December\u00a031,2018 | |||||||||||||||
| Dividend yield | 0.44% - 3.77% | 2.39% - 3.05% | 1.70% - 2.27% | ||||||||||||||
| Expected volatility | 50\u00a0 | % | 50\u00a0 | % | 45\u00a0 | % | |||||||||||
| Risk-free interest rate | 0.37% - 1.22% | 1.79% - 2.63% | 2.84% - 2.98% | ||||||||||||||
| Expected term in years | 6.5 years | 6.5 years | 6.5 years |
| \u00a0 | Options Outstanding | Options Exercisable | ||||||||||||||||||||||||||||||||||||
| Range of Exercise Prices | Number Outstanding | Weighted Average Remaining Contractual Life in Years | Weighted Average Exercise Prices | Number Exercisable | Weighted Average Exercise Prices | |||||||||||||||||||||||||||||||||
| $7.28 | - | $20.00 | 1,248,935\u00a0 | 7.9 | $13.66 | 342,574\u00a0 | $ | 15.38\u00a0 |
| Number of Shares | Weighted- Average Exercise Price | |||||||||||||
| Outstanding unvested as of December 31, 2019 | 931,658\u00a0 | $ | 15.06\u00a0 | |||||||||||
| \u00a0\u00a0\u00a0\u00a0Granted | 308,875\u00a0 | 8.99\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Vested | (190,212) | 15.13\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Forfeited | (143,960) | 14.82\u00a0 | ||||||||||||
| Outstanding unvested as of December 31, 2020 | 906,361\u00a0 | $ | 13.01\u00a0 |
| 2020 | 2019 | 2018 | |||||||||||||||
| Award type: | |||||||||||||||||
| \u00a0\u00a0\u00a0\u00a0Stock options | 308,875\u00a0 | 229,250\u00a0 | 979,790\u00a0 | ||||||||||||||
| \u00a0\u00a0\u00a0\u00a0Deferred share units | 58,207\u00a0 | 31,829\u00a0 | 42,243\u00a0 | ||||||||||||||
| \u00a0\u00a0\u00a0\u00a0Restricted stock units | 334,062\u00a0 | 260,640\u00a0 | 6,740\u00a0 |
| Number of Shares | Weighted- Average Grant Date Fair Value | |||||||||||||
| Outstanding unvested as of December 31, 2019 | 282,716\u00a0 | $ | 12.83\u00a0 | |||||||||||
| \u00a0\u00a0\u00a0\u00a0Granted | 392,269\u00a0 | 8.84\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Cancelled | (45,760) | 12.24\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Vested | (104,737) | 10.30\u00a0 | ||||||||||||
| Outstanding unvested as of December 31, 2020 | 524,488\u00a0 | $ | 10.41\u00a0 |
| Number of Shares | Weighted- Average Exercise Price | |||||||||||||
| Outstanding unvested as of December 31, 2019 | 931,658\u00a0 | $ | 15.06\u00a0 | |||||||||||
| \u00a0\u00a0\u00a0\u00a0Granted | 308,875\u00a0 | 8.99\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Vested | (190,212) | 15.13\u00a0 | ||||||||||||
| \u00a0\u00a0\u00a0\u00a0Forfeited | (143,960) | 14.82\u00a0 | ||||||||||||
| Outstanding unvested as of December 31, 2020 | 906,361\u00a0 | $ | 13.01\u00a0 |
| For the Year Ended December\u00a031,2020 | For the Year Ended December\u00a031,2019 | For the Year Ended December\u00a031,2018 | |||||||||||||||
| Dividend yield | 0.44% - 3.77% | 2.39% - 3.05% | 1.70% - 2.27% | ||||||||||||||
| Expected volatility | 50\u00a0 | % | 50\u00a0 | % | 45\u00a0 | % | |||||||||||
| Risk-free interest rate | 0.37% - 1.22% | 1.79% - 2.63% | 2.84% - 2.98% | ||||||||||||||
| Expected term in years | 6.5 years | 6.5 years | 6.5 years |
| \u00a0 | Options Outstanding | Options Exercisable | ||||||||||||||||||||||||||||||||||||
| Range of Exercise Prices | Number Outstanding | Weighted Average Remaining Contractual Life in Years | Weighted Average Exercise Prices | Number Exercisable | Weighted Average Exercise Prices | |||||||||||||||||||||||||||||||||
| $7.28 | - | $20.00 | 1,248,935\u00a0 | 7.9 | $13.66 | 342,574\u00a0 | $ | 15.38\u00a0 |
| 2020 | 2019 | 2018 | |||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| Net sales: | |||||||||||||||||
| United States | $ | 260,867\u00a0 | $ | 403,916\u00a0 | $ | 429,599\u00a0 | |||||||||||
| Americas (excluding the United States) | 187,779\u00a0 | 348,670\u00a0 | 367,561\u00a0 | ||||||||||||||
| Asia Pacific | 127,415\u00a0 | 172,439\u00a0 | 131,578\u00a0 | ||||||||||||||
| Europe, Middle East, Africa | 648,300\u00a0 | 865,768\u00a0 | 967,172\u00a0 | ||||||||||||||
| Total | $ | 1,224,361\u00a0 | $ | 1,790,793\u00a0 | $ | 1,895,910\u00a0 |
| \u00a0 | At December\u00a031, | ||||||||||
| 2020 | 2019 | ||||||||||
| (Dollars in thousands) | |||||||||||
| Long-lived assets (a): | |||||||||||
| United States | $ | 169,208\u00a0 | $ | 174,307\u00a0 | |||||||
| Mexico | 132,867\u00a0 | 141,621\u00a0 | |||||||||
| Brazil | 4,309\u00a0 | 5,694\u00a0 | |||||||||
| France | 92,805\u00a0 | 88,514\u00a0 | |||||||||
| Spain | 106,467\u00a0 | 102,577\u00a0 | |||||||||
| Other countries | 561\u00a0 | 307\u00a0 | |||||||||
| Total | $ | 506,217\u00a0 | $ | 513,020\u00a0 |
| 2020 | 2019 | 2018 | |||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| Net sales: | |||||||||||||||||
| United States | $ | 260,867\u00a0 | $ | 403,916\u00a0 | $ | 429,599\u00a0 | |||||||||||
| Americas (excluding the United States) | 187,779\u00a0 | 348,670\u00a0 | 367,561\u00a0 | ||||||||||||||
| Asia Pacific | 127,415\u00a0 | 172,439\u00a0 | 131,578\u00a0 | ||||||||||||||
| Europe, Middle East, Africa | 648,300\u00a0 | 865,768\u00a0 | 967,172\u00a0 | ||||||||||||||
| Total | $ | 1,224,361\u00a0 | $ | 1,790,793\u00a0 | $ | 1,895,910\u00a0 |
| \u00a0 | At December\u00a031, | ||||||||||
| 2020 | 2019 | ||||||||||
| (Dollars in thousands) | |||||||||||
| Long-lived assets (a): | |||||||||||
| United States | $ | 169,208\u00a0 | $ | 174,307\u00a0 | |||||||
| Mexico | 132,867\u00a0 | 141,621\u00a0 | |||||||||
| Brazil | 4,309\u00a0 | 5,694\u00a0 | |||||||||
| France | 92,805\u00a0 | 88,514\u00a0 | |||||||||
| Spain | 106,467\u00a0 | 102,577\u00a0 | |||||||||
| Other countries | 561\u00a0 | 307\u00a0 | |||||||||
| Total | $ | 506,217\u00a0 | $ | 513,020\u00a0 |
| As of December 31, 2020 | As of December 31, 2019 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| 2018 Credit Facility (2018 Term Loan and 2018 Revolving Facility) | $ | 943,708\u00a0 | $ | 1,843,750\u00a0 | |||||||
| 2020 Senior Notes | $ | 500,000\u00a0 | \u2014\u00a0 | ||||||||
| Other Debt | 615\u00a0 | 705\u00a0 | |||||||||
| Unamortized debt discount and issuance costs | (24,192) | (31,632) | |||||||||
| Total Debt | 1,420,131\u00a0 | 1,812,823\u00a0 | |||||||||
| Less: Short-term Debt | (131) | (141) | |||||||||
| Long-term Debt | $ | 1,420,000\u00a0 | $ | 1,812,682\u00a0 |
| As of December 31, 2020 | As of December 31, 2019 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| 2018 Credit Facility (2018 Term Loan and 2018 Revolving Facility) | $ | 943,708\u00a0 | $ | 1,843,750\u00a0 | |||||||
| 2020 Senior Notes | $ | 500,000\u00a0 | \u2014\u00a0 | ||||||||
| Other Debt | 615\u00a0 | 705\u00a0 | |||||||||
| Unamortized debt discount and issuance costs | (24,192) | (31,632) | |||||||||
| Total Debt | 1,420,131\u00a0 | 1,812,823\u00a0 | |||||||||
| Less: Short-term Debt | (131) | (141) | |||||||||
| Long-term Debt | $ | 1,420,000\u00a0 | $ | 1,812,682\u00a0 |
| \u00a0 | As of December 31, 2020 | As of December 31, 2019 | |||||||||||||||||||||||||||||||||
| Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | ||||||||||||||||||||||||||||||
| (Dollars in thousands) | |||||||||||||||||||||||||||||||||||
| Trade name | $ | 22,500\u00a0 | $ | (11,932) | $ | 10,568\u00a0 | $ | 22,500\u00a0 | $ | (9,861) | $ | 12,639\u00a0 | |||||||||||||||||||||||
| Technology\u00a0and know-how | 55,300\u00a0 | (34,091) | 21,209\u00a0 | 55,300\u00a0 | (29,112) | 26,188\u00a0 | |||||||||||||||||||||||||||||
| Customer\u00a0related\u00a0intangible | 64,500\u00a0 | (23,848) | 40,652\u00a0 | 64,500\u00a0 | (19,473) | 45,027\u00a0 | |||||||||||||||||||||||||||||
| Total finite-lived intangible assets | $ | 142,300\u00a0 | $ | (69,871) | $ | 72,429\u00a0 | $ | 142,300\u00a0 | $ | (58,446) | $ | 83,854\u00a0 |
| \u00a0 | As of December 31, 2020 | As of December 31, 2019 | |||||||||||||||||||||||||||||||||
| Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | ||||||||||||||||||||||||||||||
| (Dollars in thousands) | |||||||||||||||||||||||||||||||||||
| Trade name | $ | 22,500\u00a0 | $ | (11,932) | $ | 10,568\u00a0 | $ | 22,500\u00a0 | $ | (9,861) | $ | 12,639\u00a0 | |||||||||||||||||||||||
| Technology\u00a0and know-how | 55,300\u00a0 | (34,091) | 21,209\u00a0 | 55,300\u00a0 | (29,112) | 26,188\u00a0 | |||||||||||||||||||||||||||||
| Customer\u00a0related\u00a0intangible | 64,500\u00a0 | (23,848) | 40,652\u00a0 | 64,500\u00a0 | (19,473) | 45,027\u00a0 | |||||||||||||||||||||||||||||
| Total finite-lived intangible assets | $ | 142,300\u00a0 | $ | (69,871) | $ | 72,429\u00a0 | $ | 142,300\u00a0 | $ | (58,446) | $ | 83,854\u00a0 |
| \u00a0 | For the Year Ended December 31 | ||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| Interest incurred on debt | $ | 83,555\u00a0 | $ | 121,010\u00a0 | $ | 100,844\u00a0 | |||||||||||
| Related Party Promissory Note interest expense | \u2014\u00a0 | \u2014\u00a0 | 5,090\u00a0 | ||||||||||||||
| 2012 Senior Note redemption premium | \u2014\u00a0 | \u2014\u00a0 | 4,782\u00a0 | ||||||||||||||
| Accretion of fair value adjustment on 2012 Senior Notes | \u2014\u00a0 | \u2014\u00a0 | 19,414\u00a0 | ||||||||||||||
| Accretion of original issue discount on 2018 Term Loans | 5,340\u00a0 | 2,196\u00a0 | 1,455\u00a0 | ||||||||||||||
| Amortization of debt issuance costs | 9,179\u00a0 | 4,125\u00a0 | 3,476\u00a0 | ||||||||||||||
| Total interest expense | $ | 98,074\u00a0 | $ | 127,331\u00a0 | $ | 135,061\u00a0 |
| \u00a0 | For the Year Ended December 31 | ||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| Interest incurred on debt | $ | 83,555\u00a0 | $ | 121,010\u00a0 | $ | 100,844\u00a0 | |||||||||||
| Related Party Promissory Note interest expense | \u2014\u00a0 | \u2014\u00a0 | 5,090\u00a0 | ||||||||||||||
| 2012 Senior Note redemption premium | \u2014\u00a0 | \u2014\u00a0 | 4,782\u00a0 | ||||||||||||||
| Accretion of fair value adjustment on 2012 Senior Notes | \u2014\u00a0 | \u2014\u00a0 | 19,414\u00a0 | ||||||||||||||
| Accretion of original issue discount on 2018 Term Loans | 5,340\u00a0 | 2,196\u00a0 | 1,455\u00a0 | ||||||||||||||
| Amortization of debt issuance costs | 9,179\u00a0 | 4,125\u00a0 | 3,476\u00a0 | ||||||||||||||
| Total interest expense | $ | 98,074\u00a0 | $ | 127,331\u00a0 | $ | 135,061\u00a0 |
| Asset Derivatives | Liability Derivatives | ||||||||||||||||||||||
| \u00a0 | Location | Fair\u00a0 Value | Location | Fair\u00a0 Value | |||||||||||||||||||
| As of December 31, 2020 | (Dollars in thousands) | ||||||||||||||||||||||
| Derivatives designated as cash flow hedges: | |||||||||||||||||||||||
| Commodity derivative contracts | Prepaid and other current assets | $ | 518\u00a0 | Other accrued liabilities | $ | 888\u00a0 | |||||||||||||||||
| Other long-term assets | 63\u00a0 | Other long-term obligations | 1,898\u00a0 | ||||||||||||||||||||
| Interest rate swap contracts | Prepaid and other current assets | \u2014\u00a0 | Other accrued liabilities | 4,080\u00a0 | |||||||||||||||||||
| Other long-term assets | \u2014\u00a0 | Other long-term obligations | 6,903\u00a0 | ||||||||||||||||||||
| Total fair value | $ | 581\u00a0 | $ | 13,769\u00a0 | |||||||||||||||||||
| As of December 31, 2019 | |||||||||||||||||||||||
| Commodity derivative contracts | Prepaid and other current assets | $ | 104\u00a0 | Other accrued liabilities | $ | 1,872\u00a0 | |||||||||||||||||
| Other long-term assets | 369\u00a0 | Other long-term obligations | 2,255\u00a0 | ||||||||||||||||||||
| Interest rate swap contracts | Prepaid and other current assets | $ | 253\u00a0 | Other accrued liabilities | $ | \u2014\u00a0 | |||||||||||||||||
| Other long-term assets | $ | 2,684\u00a0 | Other long-term obligations | $ | 72\u00a0 | ||||||||||||||||||
| Total fair value | $ | 3,410\u00a0 | $ | 4,199\u00a0 | |||||||||||||||||||
| \u00a0 | Asset Derivatives | Liability Derivatives | |||||||||||||||||||||
| \u00a0 | Location | Fair\u00a0 Value | Location | Fair\u00a0 Value | |||||||||||||||||||
| As of December 31, 2020 | (Dollars in Thousands) | ||||||||||||||||||||||
| Derivatives not designated as hedges: | |||||||||||||||||||||||
| Foreign currency derivatives | Prepaid and other current assets | $ | 6\u00a0 | Other accrued liabilities | $ | 111\u00a0 | |||||||||||||||||
| Interest rate swap contracts | Prepaid and other current assets | \u2014\u00a0 | Other accrued liabilities | 952 | |||||||||||||||||||
| Total fair value | $ | 6\u00a0 | $ | 1,063\u00a0 | |||||||||||||||||||
| As of December 31, 2019 | |||||||||||||||||||||||
| Derivatives not designated as hedges: | |||||||||||||||||||||||
| Foreign currency derivatives | Prepaid and other current assets | $ | 239\u00a0 | Other accrued liabilities | $ | 81\u00a0 | |||||||||||||||||
| Commodity derivative contracts | Prepaid and other current assets | 376\u00a0 | Other accrued liabilities | \u2014\u00a0 | |||||||||||||||||||
| Total fair value | $ | 615\u00a0 | $ | 81\u00a0 |
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||||||||
| Location of Realized (Gain)/Loss Recognized in the Consolidated Statement of Operations | 2020 | 2019 | 2018 | |||||||||||||||||||||||
| Derivatives designated as cash flow hedges: | (Dollars in thousands) | |||||||||||||||||||||||||
| Commodity derivative contracts | Cost of sales | $ | (4,134) | $ | (8,892) | $ | (919) | |||||||||||||||||||
| Interest rate swaps | Interest expense (income) | 4,390\u00a0 | (1,050) | \u2014\u00a0 |
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||||||||
| Location of Realized (Gain)/Loss Recognized in the Consolidated Statement of Operations | 2020 | 2019 | 2018 | |||||||||||||||||||||||
| Derivatives not designated as hedges: | (Dollars in thousands) | |||||||||||||||||||||||||
| Foreign currency derivatives | Cost of sales, Other expense/(income) | $ | (2,671) | $ | (506) | $ | (522) | |||||||||||||||||||
| Commodity derivative contracts | Cost of sales | (530) | (223) | \u2014\u00a0 |
| \u00a0 | Asset Derivatives | Liability Derivatives | |||||||||||||||||||||
| \u00a0 | Location | Fair\u00a0 Value | Location | Fair\u00a0 Value | |||||||||||||||||||
| As of December 31, 2020 | (Dollars in Thousands) | ||||||||||||||||||||||
| Derivatives not designated as hedges: | |||||||||||||||||||||||
| Foreign currency derivatives | Prepaid and other current assets | $ | 6\u00a0 | Other accrued liabilities | $ | 111\u00a0 | |||||||||||||||||
| Interest rate swap contracts | Prepaid and other current assets | \u2014\u00a0 | Other accrued liabilities | 952 | |||||||||||||||||||
| Total fair value | $ | 6\u00a0 | $ | 1,063\u00a0 | |||||||||||||||||||
| As of December 31, 2019 | |||||||||||||||||||||||
| Derivatives not designated as hedges: | |||||||||||||||||||||||
| Foreign currency derivatives | Prepaid and other current assets | $ | 239\u00a0 | Other accrued liabilities | $ | 81\u00a0 | |||||||||||||||||
| Commodity derivative contracts | Prepaid and other current assets | 376\u00a0 | Other accrued liabilities | \u2014\u00a0 | |||||||||||||||||||
| Total fair value | $ | 615\u00a0 | $ | 81\u00a0 |
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||||||||
| Location of Realized (Gain)/Loss Recognized in the Consolidated Statement of Operations | 2020 | 2019 | 2018 | |||||||||||||||||||||||
| Derivatives designated as cash flow hedges: | (Dollars in thousands) | |||||||||||||||||||||||||
| Commodity derivative contracts | Cost of sales | $ | (4,134) | $ | (8,892) | $ | (919) | |||||||||||||||||||
| Interest rate swaps | Interest expense (income) | 4,390\u00a0 | (1,050) | \u2014\u00a0 |
| \u00a0 | \u00a0 | Amount\u00a0of\u00a0(Gain)/Loss Recognized | ||||||||||||||||||||||||
| Location of Realized (Gain)/Loss Recognized in the Consolidated Statement of Operations | 2020 | 2019 | 2018 | |||||||||||||||||||||||
| Derivatives not designated as hedges: | (Dollars in thousands) | |||||||||||||||||||||||||
| Foreign currency derivatives | Cost of sales, Other expense/(income) | $ | (2,671) | $ | (506) | $ | (522) | |||||||||||||||||||
| Commodity derivative contracts | Cost of sales | (530) | (223) | \u2014\u00a0 |
| As of December 31, 2020 | As of December 31, 2019 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| Inventories *: | |||||||||||
| \u00a0\u00a0\u00a0Raw materials and supplies | $ | 101,098\u00a0 | $ | 129,879\u00a0 | |||||||
| \u00a0\u00a0\u00a0Work in process | 110,331\u00a0 | 131,435\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Finished goods | 54,535\u00a0 | 52,334\u00a0 | |||||||||
| $ | 265,964\u00a0 | $ | 313,648\u00a0 | ||||||||
| Prepaid expenses and other current assets: | |||||||||||
| \u00a0\u00a0\u00a0Prepaid expenses | $ | 9,242\u00a0 | $ | 9,986\u00a0 | |||||||
| \u00a0\u00a0\u00a0Value added tax and other indirect taxes receivable | 10,666\u00a0 | 13,890\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Spare parts inventory | 11,825\u00a0 | 12,738\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Other current assets | 3,381\u00a0 | 4,332\u00a0 | |||||||||
| $ | 35,114\u00a0 | $ | 40,946\u00a0 | ||||||||
| Property, plant and equipment: | |||||||||||
| \u00a0\u00a0\u00a0Land and improvements | $ | 50,285\u00a0 | $ | 46,548\u00a0 | |||||||
| \u00a0\u00a0\u00a0Buildings | 80,041\u00a0 | 71,784\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Machinery and equipment and other | 621,478\u00a0 | 567,715\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Construction in progress | 33,098\u00a0 | 47,370\u00a0 | |||||||||
| $ | 784,902\u00a0 | $ | 733,417\u00a0 | ||||||||
| Other accrued liabilities: | |||||||||||
| \u00a0\u00a0\u00a0Payrolls (including incentive programs) | $ | 13,159\u00a0 | $ | 11,801\u00a0 | |||||||
| \u00a0\u00a0\u00a0Employee benefits | 7,128\u00a0 | 7,416\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Deferred revenue | 13,056\u00a0 | 11,776\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Other | 23,158\u00a0 | 17,342\u00a0 | |||||||||
| $ | 56,501\u00a0 | $ | 48,335\u00a0 | ||||||||
| Other long term obligations: | |||||||||||
| \u00a0\u00a0\u00a0Postretirement benefits | $ | 15,669\u00a0 | $ | 16,528\u00a0 | |||||||
| \u00a0\u00a0\u00a0Pension and related benefits | 37,847\u00a0 | 37,431\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Other | 27,962\u00a0 | 18,603\u00a0 | |||||||||
| $ | 81,478\u00a0 | $ | 72,562\u00a0 |
| 2020 | 2019 | 2018 | |||||||||||||||
| \u00a0 | |||||||||||||||||
| Balance at beginning of year | $ | 5,474\u00a0 | $ | 1,129\u00a0 | $ | 1,097\u00a0 | |||||||||||
| ASC 326 adoption impact | 2,026\u00a0 | \u2014\u00a0 | \u2014\u00a0 | ||||||||||||||
| Additions | 1,458\u00a0 | 4,636\u00a0 | 122\u00a0 | ||||||||||||||
| Deductions | (715) | (291) | (90) | ||||||||||||||
| Balance at end of year | $ | 8,243\u00a0 | $ | 5,474\u00a0 | $ | 1,129\u00a0 |
| As of December 31, 2020 | As of December 31, 2019 | ||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||
| Inventories *: | |||||||||||
| \u00a0\u00a0\u00a0Raw materials and supplies | $ | 101,098\u00a0 | $ | 129,879\u00a0 | |||||||
| \u00a0\u00a0\u00a0Work in process | 110,331\u00a0 | 131,435\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Finished goods | 54,535\u00a0 | 52,334\u00a0 | |||||||||
| $ | 265,964\u00a0 | $ | 313,648\u00a0 | ||||||||
| Prepaid expenses and other current assets: | |||||||||||
| \u00a0\u00a0\u00a0Prepaid expenses | $ | 9,242\u00a0 | $ | 9,986\u00a0 | |||||||
| \u00a0\u00a0\u00a0Value added tax and other indirect taxes receivable | 10,666\u00a0 | 13,890\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Spare parts inventory | 11,825\u00a0 | 12,738\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Other current assets | 3,381\u00a0 | 4,332\u00a0 | |||||||||
| $ | 35,114\u00a0 | $ | 40,946\u00a0 | ||||||||
| Property, plant and equipment: | |||||||||||
| \u00a0\u00a0\u00a0Land and improvements | $ | 50,285\u00a0 | $ | 46,548\u00a0 | |||||||
| \u00a0\u00a0\u00a0Buildings | 80,041\u00a0 | 71,784\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Machinery and equipment and other | 621,478\u00a0 | 567,715\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Construction in progress | 33,098\u00a0 | 47,370\u00a0 | |||||||||
| $ | 784,902\u00a0 | $ | 733,417\u00a0 | ||||||||
| Other accrued liabilities: | |||||||||||
| \u00a0\u00a0\u00a0Payrolls (including incentive programs) | $ | 13,159\u00a0 | $ | 11,801\u00a0 | |||||||
| \u00a0\u00a0\u00a0Employee benefits | 7,128\u00a0 | 7,416\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Deferred revenue | 13,056\u00a0 | 11,776\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Other | 23,158\u00a0 | 17,342\u00a0 | |||||||||
| $ | 56,501\u00a0 | $ | 48,335\u00a0 | ||||||||
| Other long term obligations: | |||||||||||
| \u00a0\u00a0\u00a0Postretirement benefits | $ | 15,669\u00a0 | $ | 16,528\u00a0 | |||||||
| \u00a0\u00a0\u00a0Pension and related benefits | 37,847\u00a0 | 37,431\u00a0 | |||||||||
| \u00a0\u00a0\u00a0Other | 27,962\u00a0 | 18,603\u00a0 | |||||||||
| $ | 81,478\u00a0 | $ | 72,562\u00a0 |
| 2020 | 2019 | 2018 | |||||||||||||||
| \u00a0 | |||||||||||||||||
| Balance at beginning of year | $ | 5,474\u00a0 | $ | 1,129\u00a0 | $ | 1,097\u00a0 | |||||||||||
| ASC 326 adoption impact | 2,026\u00a0 | \u2014\u00a0 | \u2014\u00a0 | ||||||||||||||
| Additions | 1,458\u00a0 | 4,636\u00a0 | 122\u00a0 | ||||||||||||||
| Deductions | (715) | (291) | (90) | ||||||||||||||
| Balance at end of year | $ | 8,243\u00a0 | $ | 5,474\u00a0 | $ | 1,129\u00a0 |
| For the Year Ended December 31, | ||||||||||||||
| 2020 | 2019 | |||||||||||||
| (Dollars\u00a0in\u00a0thousands) | ||||||||||||||
| Operating lease cost | 6,138\u00a0 | 4,816\u00a0 | ||||||||||||
| Short-term lease cost | 159\u00a0 | 14\u00a0 | ||||||||||||
| Variable lease cost | 429\u00a0 | 227\u00a0 | ||||||||||||
| Total lease cost | $ | 6,726\u00a0 | $ | 5,057\u00a0 |
| For the Year Ended December 31, | ||||||||||||||
| 2020 | 2019 | |||||||||||||
| (Dollars\u00a0in\u00a0thousands) | ||||||||||||||
| RoU assets obtained in exchange for new operating lease liabilities (non-cash) | 5,262\u00a0 | 4,995\u00a0 | ||||||||||||
| Operating (use of cash) from operating leases | (6,177) | (4,724) |
| As of December 31, | |||||||||||||||||
| 2020 | 2019 | ||||||||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||||||||
| Location | |||||||||||||||||
| Operating RoU Assets | \u00a0 | $ | 7,164\u00a0 | $ | 7,994\u00a0 | ||||||||||||
| Current operating lease liabilities | Other accrued liabilities | 4,102\u00a0 | 4,475\u00a0 | ||||||||||||||
| Non-current operating lease liabilities | 3,195\u00a0 | 3,598\u00a0 | |||||||||||||||
| Total operating lease liabilities | $ | 7,297\u00a0 | $ | 8,073\u00a0 | |||||||||||||
| Weighted average remaining lease term (in years) | 2.7 | 2.3 | |||||||||||||||
| Weighted average discount rate - operating leases | 5.82\u00a0 | % | 5.61\u00a0 | % |
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | |||||||
| 2021 | 4,124\u00a0 | |||||||
| 2022 | 1,377\u00a0 | |||||||
| 2023 | 1,024\u00a0 | |||||||
| 2024 | 872\u00a0 | |||||||
| 2025 and thereafter | 449\u00a0 | |||||||
| Total lease payments | $ | 7,846\u00a0 | ||||||
| Less: Imputed interest | (549) | |||||||
| Present value of lease payments | $ | 7,297\u00a0 |
| For the Year Ended December 31, | ||||||||||||||
| 2020 | 2019 | |||||||||||||
| (Dollars\u00a0in\u00a0thousands) | ||||||||||||||
| Operating lease cost | 6,138\u00a0 | 4,816\u00a0 | ||||||||||||
| Short-term lease cost | 159\u00a0 | 14\u00a0 | ||||||||||||
| Variable lease cost | 429\u00a0 | 227\u00a0 | ||||||||||||
| Total lease cost | $ | 6,726\u00a0 | $ | 5,057\u00a0 |
| For the Year Ended December 31, | ||||||||||||||
| 2020 | 2019 | |||||||||||||
| (Dollars\u00a0in\u00a0thousands) | ||||||||||||||
| RoU assets obtained in exchange for new operating lease liabilities (non-cash) | 5,262\u00a0 | 4,995\u00a0 | ||||||||||||
| Operating (use of cash) from operating leases | (6,177) | (4,724) |
| As of December 31, | |||||||||||||||||
| 2020 | 2019 | ||||||||||||||||
| (Dollars\u00a0in\u00a0thousands) | |||||||||||||||||
| Location | |||||||||||||||||
| Operating RoU Assets | \u00a0 | $ | 7,164\u00a0 | $ | 7,994\u00a0 | ||||||||||||
| Current operating lease liabilities | Other accrued liabilities | 4,102\u00a0 | 4,475\u00a0 | ||||||||||||||
| Non-current operating lease liabilities | 3,195\u00a0 | 3,598\u00a0 | |||||||||||||||
| Total operating lease liabilities | $ | 7,297\u00a0 | $ | 8,073\u00a0 | |||||||||||||
| Weighted average remaining lease term (in years) | 2.7 | 2.3 | |||||||||||||||
| Weighted average discount rate - operating leases | 5.82\u00a0 | % | 5.61\u00a0 | % |
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | |||||||
| 2021 | 4,124\u00a0 | |||||||
| 2022 | 1,377\u00a0 | |||||||
| 2023 | 1,024\u00a0 | |||||||
| 2024 | 872\u00a0 | |||||||
| 2025 and thereafter | 449\u00a0 | |||||||
| Total lease payments | $ | 7,846\u00a0 | ||||||
| Less: Imputed interest | (549) | |||||||
| Present value of lease payments | $ | 7,297\u00a0 |
| For the Year Ended December 31, | |||||||||||||||||||||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||||||||||||
| (Dollars in thousands) | |||||||||||||||||||||||||||||||||||
| Service cost | $ | 1,322\u00a0 | $ | 1,183\u00a0 | $ | 1,297\u00a0 | $ | 624\u00a0 | $ | 1,315\u00a0 | $ | 674\u00a0 | |||||||||||||||||||||||
| Interest cost | 3,949\u00a0 | 174\u00a0 | 5,070\u00a0 | 275\u00a0 | 4,709\u00a0 | 253\u00a0 | |||||||||||||||||||||||||||||
| Expected return on assets | (4,730) | (401) | (5,026) | (424) | (5,679) | (330) | |||||||||||||||||||||||||||||
| Mark- to- market loss | 613\u00a0 | 2,596\u00a0 | 205\u00a0 | 3,302\u00a0 | 2,473\u00a0 | 503\u00a0 | |||||||||||||||||||||||||||||
| Pension costs | $ | 1,154\u00a0 | $ | 3,552\u00a0 | $ | 1,546\u00a0 | $ | 3,777\u00a0 | $ | 2,818\u00a0 | $ | 1,100\u00a0 |
| \u00a0 | As of December 31, 2020 | As of December 31, 2019 | |||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||||||||
| Changes in Benefit Obligation: | |||||||||||||||||||||||
| Net benefit obligation at beginning of period | $ | 135,810\u00a0 | $ | 28,903\u00a0 | $ | 126,985\u00a0 | $ | 22,332\u00a0 | |||||||||||||||
| Service cost | 1,322\u00a0 | 1,183\u00a0 | 1,297\u00a0 | 624\u00a0 | |||||||||||||||||||
| Interest cost | 3,949\u00a0 | 174\u00a0 | 5,070\u00a0 | 275\u00a0 | |||||||||||||||||||
| Participant contributions | \u2014\u00a0 | 470\u00a0 | \u2014\u00a0 | 417\u00a0 | |||||||||||||||||||
| Foreign currency exchange changes | \u2014\u00a0 | 2,869\u00a0 | \u2014\u00a0 | 379\u00a0 | |||||||||||||||||||
| Actuarial (gain) loss | 9,583\u00a0 | 2,683\u00a0 | 12,868\u00a0 | 3,319\u00a0 | |||||||||||||||||||
| Benefits paid* | (10,410) | 2,434\u00a0 | (10,410) | 1,557\u00a0 | |||||||||||||||||||
| Net benefit obligation at end of period | $ | 140,254\u00a0 | $ | 38,716\u00a0 | $ | 135,810\u00a0 | $ | 28,903\u00a0 | |||||||||||||||
| Changes in Plan Assets: | |||||||||||||||||||||||
| Fair value of plan assets at beginning of period | $ | 107,832\u00a0 | $ | 18,980\u00a0 | $ | 99,845\u00a0 | $ | 15,354\u00a0 | |||||||||||||||
| Actual return on plan assets | 13,700\u00a0 | 488\u00a0 | 17,689\u00a0 | 441\u00a0 | |||||||||||||||||||
| Foreign currency exchange rate changes | \u2014\u00a0 | 1,893\u00a0 | \u2014\u00a0 | 377\u00a0 | |||||||||||||||||||
| Employer contributions | 4,446\u00a0 | 817\u00a0 | 708\u00a0 | 834\u00a0 | |||||||||||||||||||
| Participant contributions | \u2014\u00a0 | 470\u00a0 | \u2014\u00a0 | 417\u00a0 | |||||||||||||||||||
| Benefits paid* | (10,410) | 2,434\u00a0 | (10,410) | 1,557\u00a0 | |||||||||||||||||||
| Fair value of plan assets at end of period | $ | 115,568\u00a0 | $ | 25,082\u00a0 | $ | 107,832\u00a0 | $ | 18,980\u00a0 | |||||||||||||||
| Funded status (underfunded): | $ | (24,686) | $ | (13,634) | $ | (27,978) | $ | (9,923) | |||||||||||||||
| Amounts recognized in the statement of financial position: | |||||||||||||||||||||||
| Non-current assets | $ | \u2014\u00a0 | $ | 13\u00a0 | $ | \u2014\u00a0 | $ | 37\u00a0 | |||||||||||||||
| Current liabilities | (423) | (50) | (427) | (43) | |||||||||||||||||||
| Non-current liabilities | (24,263) | (13,597) | (27,551) | (9,917) | |||||||||||||||||||
| Net amount recognized | $ | (24,686) | $ | (13,634) | $ | (27,978) | $ | (9,923) |
| \u00a0 | As of December 31, 2020 | ||||||||||||||||||||||
| Level\u00a01 | Level\u00a02 | Level 3 | Total | ||||||||||||||||||||
| U.S. Plan Assets | |||||||||||||||||||||||
| Cash\u00a0and\u00a0cash\u00a0equivalents | $ | 1,850\u00a0 | $ | \u2014\u00a0 | $ | \u2014\u00a0 | $ | 1,850\u00a0 | |||||||||||||||
| International\u00a0Plan\u00a0Assets | |||||||||||||||||||||||
| Foreign\u00a0government\u00a0bonds | \u2014\u00a0 | 995\u00a0 | \u2014\u00a0 | 995\u00a0 | |||||||||||||||||||
| Fixed\u00a0insurance\u00a0contracts | \u2014\u00a0 | \u2014\u00a0 | 24,087\u00a0 | 24,087\u00a0 | |||||||||||||||||||
| Total assets in the fair value hierarchy | $ | \u2014\u00a0 | $ | 995\u00a0 | $ | 24,087\u00a0 | $ | 25,082\u00a0 | |||||||||||||||
| U.S. Plan - Investments measured at net asset value | $ | 113,718\u00a0 | |||||||||||||||||||||
| Total | $ | 1,850\u00a0 | $ | 995\u00a0 | $ | 24,087\u00a0 | $ | 140,650\u00a0 | |||||||||||||||
| As of December 31, 2019 | |||||||||||||||||||||||
| Level\u00a01 | Level 2 | Level 3 | Total | ||||||||||||||||||||
| U.S. Plan Assets | |||||||||||||||||||||||
| Cash\u00a0and\u00a0cash\u00a0equivalents | $ | 1,524\u00a0 | $ | \u2014\u00a0 | $ | \u2014\u00a0 | $ | 1,524\u00a0 | |||||||||||||||
| International\u00a0Plan\u00a0Assets | |||||||||||||||||||||||
| Foreign\u00a0government\u00a0bonds | $ | \u2014\u00a0 | $ | 995\u00a0 | $ | \u2014\u00a0 | $ | 995\u00a0 | |||||||||||||||
| Fixed\u00a0insurance\u00a0contracts | \u2014\u00a0 | \u2014\u00a0 | 17,985\u00a0 | 17,985\u00a0 | |||||||||||||||||||
| Total assets in the fair value hierarchy | $ | \u2014\u00a0 | $ | 995\u00a0 | $ | 17,985\u00a0 | $ | 18,980\u00a0 | |||||||||||||||
| U.S. Plan - Investments measured at net asset value | $ | 106,308\u00a0 | |||||||||||||||||||||
| Total | $ | 1,524\u00a0 | $ | 995\u00a0 | $ | 17,985\u00a0 | $ | 126,812\u00a0 | |||||||||||||||
| Fixed\u00a0Insurance Contracts | |||||
| Balance at December\u00a031, 2018 | $ | 14,396\u00a0 | |||
| \u00a0\u00a0\u00a0Gain / contributions / currency impact | 3,603\u00a0 | ||||
| \u00a0\u00a0\u00a0Distributions | (14) | ||||
| Balance at December\u00a031, 2019 | 17,985\u00a0 | ||||
| \u00a0\u00a0\u00a0Gain / contributions / currency impact | 6,149\u00a0 | ||||
| \u00a0\u00a0\u00a0Distributions | (16) | ||||
| Balance at December\u00a031, 2020 | $ | 24,118\u00a0 |
| Pension Benefit Obligations Key Assumptions | As of December\u00a031, | ||||||||||
| \u00a0 | 2020 | 2019 | |||||||||
| Weighted average assumptions to determine benefit obligations: | |||||||||||
| Discount rate | 1.78\u00a0 | % | 2.59\u00a0 | % | |||||||
| Rate\u00a0of\u00a0compensation\u00a0increase | 1.46\u00a0 | % | 1.50\u00a0 | % |
| Pension Cost Key Assumptions | |||||||||||
| Weighted average assumptions to determine net cost: | |||||||||||
| Discount rate | 2.59\u00a0 | % | 3.71\u00a0 | % | |||||||
| Expected return on plan assets | 4.14\u00a0 | % | 4.92\u00a0 | % | |||||||
| Rate of compensation increase | 1.50\u00a0 | % | 1.74\u00a0 | % |
| \u00a0 | Percentage\u00a0of\u00a0Plan\u00a0Assets as of\u00a0December\u00a031, 2020 | ||||||||||
| \u00a0 | US | Foreign | |||||||||
| Equity securities and return seeking assets | 20\u00a0 | % | \u2014\u00a0 | % | |||||||
| Fixed income, debt securities, or cash | 80\u00a0 | % | 100\u00a0 | % | |||||||
| Total | 100\u00a0 | % | 100\u00a0 | % |
| \u00a0 | 2020 | 2019 | |||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||||||||
| Accumulated benefit obligation | $ | 140,254\u00a0 | $ | 35,316\u00a0 | $ | 135,810\u00a0 | $ | 26,829\u00a0 | |||||||||||||||
| Fair value of plan assets | 115,568\u00a0 | 24,118\u00a0 | 107,832\u00a0 | 17,985\u00a0 |
| \u00a0 | 2020 | 2019 | |||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||||||||
| Projected benefit obligation | $ | 140,254\u00a0 | $ | 37,734\u00a0 | $ | 135,810\u00a0 | $ | 27,944\u00a0 | |||||||||||||||
| Fair value of plan assets | 115,568\u00a0 | 24,118\u00a0 | 107,832\u00a0 | 17,985\u00a0 |
| U.S. | Foreign | ||||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Expected contributions in 2021: | |||||||||||
| Expected employer contributions | $ | 2,363\u00a0 | $ | 886\u00a0 | |||||||
| Expected employee contributions | \u2014\u00a0 | \u2014\u00a0 | |||||||||
| Estimated future benefit payments reflecting expected future service for the years ending December\u00a031: | |||||||||||
| 2021 | 9,254\u00a0 | 1,102\u00a0 | |||||||||
| 2022 | 9,211\u00a0 | 1,087\u00a0 | |||||||||
| 2023 | 9,149\u00a0 | 1,229\u00a0 | |||||||||
| 2024 | 9,022\u00a0 | 2,763\u00a0 | |||||||||
| 2025 | 8,976\u00a0 | 1,330\u00a0 | |||||||||
| 2026-2030 | 42,021\u00a0 | 13,164\u00a0 |
| For the Year Ended December 31, | |||||||||||||||||||||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||||||||||||
| (Dollars in thousands) | |||||||||||||||||||||||||||||||||||
| Service cost | $ | 1,322\u00a0 | $ | 1,183\u00a0 | $ | 1,297\u00a0 | $ | 624\u00a0 | $ | 1,315\u00a0 | $ | 674\u00a0 | |||||||||||||||||||||||
| Interest cost | 3,949\u00a0 | 174\u00a0 | 5,070\u00a0 | 275\u00a0 | 4,709\u00a0 | 253\u00a0 | |||||||||||||||||||||||||||||
| Expected return on assets | (4,730) | (401) | (5,026) | (424) | (5,679) | (330) | |||||||||||||||||||||||||||||
| Mark- to- market loss | 613\u00a0 | 2,596\u00a0 | 205\u00a0 | 3,302\u00a0 | 2,473\u00a0 | 503\u00a0 | |||||||||||||||||||||||||||||
| Pension costs | $ | 1,154\u00a0 | $ | 3,552\u00a0 | $ | 1,546\u00a0 | $ | 3,777\u00a0 | $ | 2,818\u00a0 | $ | 1,100\u00a0 |
| \u00a0 | As of December 31, 2020 | As of December 31, 2019 | |||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||||||||
| Changes in Benefit Obligation: | |||||||||||||||||||||||
| Net benefit obligation at beginning of period | $ | 135,810\u00a0 | $ | 28,903\u00a0 | $ | 126,985\u00a0 | $ | 22,332\u00a0 | |||||||||||||||
| Service cost | 1,322\u00a0 | 1,183\u00a0 | 1,297\u00a0 | 624\u00a0 | |||||||||||||||||||
| Interest cost | 3,949\u00a0 | 174\u00a0 | 5,070\u00a0 | 275\u00a0 | |||||||||||||||||||
| Participant contributions | \u2014\u00a0 | 470\u00a0 | \u2014\u00a0 | 417\u00a0 | |||||||||||||||||||
| Foreign currency exchange changes | \u2014\u00a0 | 2,869\u00a0 | \u2014\u00a0 | 379\u00a0 | |||||||||||||||||||
| Actuarial (gain) loss | 9,583\u00a0 | 2,683\u00a0 | 12,868\u00a0 | 3,319\u00a0 | |||||||||||||||||||
| Benefits paid* | (10,410) | 2,434\u00a0 | (10,410) | 1,557\u00a0 | |||||||||||||||||||
| Net benefit obligation at end of period | $ | 140,254\u00a0 | $ | 38,716\u00a0 | $ | 135,810\u00a0 | $ | 28,903\u00a0 | |||||||||||||||
| Changes in Plan Assets: | |||||||||||||||||||||||
| Fair value of plan assets at beginning of period | $ | 107,832\u00a0 | $ | 18,980\u00a0 | $ | 99,845\u00a0 | $ | 15,354\u00a0 | |||||||||||||||
| Actual return on plan assets | 13,700\u00a0 | 488\u00a0 | 17,689\u00a0 | 441\u00a0 | |||||||||||||||||||
| Foreign currency exchange rate changes | \u2014\u00a0 | 1,893\u00a0 | \u2014\u00a0 | 377\u00a0 | |||||||||||||||||||
| Employer contributions | 4,446\u00a0 | 817\u00a0 | 708\u00a0 | 834\u00a0 | |||||||||||||||||||
| Participant contributions | \u2014\u00a0 | 470\u00a0 | \u2014\u00a0 | 417\u00a0 | |||||||||||||||||||
| Benefits paid* | (10,410) | 2,434\u00a0 | (10,410) | 1,557\u00a0 | |||||||||||||||||||
| Fair value of plan assets at end of period | $ | 115,568\u00a0 | $ | 25,082\u00a0 | $ | 107,832\u00a0 | $ | 18,980\u00a0 | |||||||||||||||
| Funded status (underfunded): | $ | (24,686) | $ | (13,634) | $ | (27,978) | $ | (9,923) | |||||||||||||||
| Amounts recognized in the statement of financial position: | |||||||||||||||||||||||
| Non-current assets | $ | \u2014\u00a0 | $ | 13\u00a0 | $ | \u2014\u00a0 | $ | 37\u00a0 | |||||||||||||||
| Current liabilities | (423) | (50) | (427) | (43) | |||||||||||||||||||
| Non-current liabilities | (24,263) | (13,597) | (27,551) | (9,917) | |||||||||||||||||||
| Net amount recognized | $ | (24,686) | $ | (13,634) | $ | (27,978) | $ | (9,923) |
| \u00a0 | As of December 31, 2020 | ||||||||||||||||||||||
| Level\u00a01 | Level\u00a02 | Level 3 | Total | ||||||||||||||||||||
| U.S. Plan Assets | |||||||||||||||||||||||
| Cash\u00a0and\u00a0cash\u00a0equivalents | $ | 1,850\u00a0 | $ | \u2014\u00a0 | $ | \u2014\u00a0 | $ | 1,850\u00a0 | |||||||||||||||
| International\u00a0Plan\u00a0Assets | |||||||||||||||||||||||
| Foreign\u00a0government\u00a0bonds | \u2014\u00a0 | 995\u00a0 | \u2014\u00a0 | 995\u00a0 | |||||||||||||||||||
| Fixed\u00a0insurance\u00a0contracts | \u2014\u00a0 | \u2014\u00a0 | 24,087\u00a0 | 24,087\u00a0 | |||||||||||||||||||
| Total assets in the fair value hierarchy | $ | \u2014\u00a0 | $ | 995\u00a0 | $ | 24,087\u00a0 | $ | 25,082\u00a0 | |||||||||||||||
| U.S. Plan - Investments measured at net asset value | $ | 113,718\u00a0 | |||||||||||||||||||||
| Total | $ | 1,850\u00a0 | $ | 995\u00a0 | $ | 24,087\u00a0 | $ | 140,650\u00a0 | |||||||||||||||
| As of December 31, 2019 | |||||||||||||||||||||||
| Level\u00a01 | Level 2 | Level 3 | Total | ||||||||||||||||||||
| U.S. Plan Assets | |||||||||||||||||||||||
| Cash\u00a0and\u00a0cash\u00a0equivalents | $ | 1,524\u00a0 | $ | \u2014\u00a0 | $ | \u2014\u00a0 | $ | 1,524\u00a0 | |||||||||||||||
| International\u00a0Plan\u00a0Assets | |||||||||||||||||||||||
| Foreign\u00a0government\u00a0bonds | $ | \u2014\u00a0 | $ | 995\u00a0 | $ | \u2014\u00a0 | $ | 995\u00a0 | |||||||||||||||
| Fixed\u00a0insurance\u00a0contracts | \u2014\u00a0 | \u2014\u00a0 | 17,985\u00a0 | 17,985\u00a0 | |||||||||||||||||||
| Total assets in the fair value hierarchy | $ | \u2014\u00a0 | $ | 995\u00a0 | $ | 17,985\u00a0 | $ | 18,980\u00a0 | |||||||||||||||
| U.S. Plan - Investments measured at net asset value | $ | 106,308\u00a0 | |||||||||||||||||||||
| Total | $ | 1,524\u00a0 | $ | 995\u00a0 | $ | 17,985\u00a0 | $ | 126,812\u00a0 | |||||||||||||||
| Fixed\u00a0Insurance Contracts | |||||
| Balance at December\u00a031, 2018 | $ | 14,396\u00a0 | |||
| \u00a0\u00a0\u00a0Gain / contributions / currency impact | 3,603\u00a0 | ||||
| \u00a0\u00a0\u00a0Distributions | (14) | ||||
| Balance at December\u00a031, 2019 | 17,985\u00a0 | ||||
| \u00a0\u00a0\u00a0Gain / contributions / currency impact | 6,149\u00a0 | ||||
| \u00a0\u00a0\u00a0Distributions | (16) | ||||
| Balance at December\u00a031, 2020 | $ | 24,118\u00a0 |
| Pension Benefit Obligations Key Assumptions | As of December\u00a031, | ||||||||||
| \u00a0 | 2020 | 2019 | |||||||||
| Weighted average assumptions to determine benefit obligations: | |||||||||||
| Discount rate | 1.78\u00a0 | % | 2.59\u00a0 | % | |||||||
| Rate\u00a0of\u00a0compensation\u00a0increase | 1.46\u00a0 | % | 1.50\u00a0 | % |
| Pension Cost Key Assumptions | |||||||||||
| Weighted average assumptions to determine net cost: | |||||||||||
| Discount rate | 2.59\u00a0 | % | 3.71\u00a0 | % | |||||||
| Expected return on plan assets | 4.14\u00a0 | % | 4.92\u00a0 | % | |||||||
| Rate of compensation increase | 1.50\u00a0 | % | 1.74\u00a0 | % |
| \u00a0 | Percentage\u00a0of\u00a0Plan\u00a0Assets as of\u00a0December\u00a031, 2020 | ||||||||||
| \u00a0 | US | Foreign | |||||||||
| Equity securities and return seeking assets | 20\u00a0 | % | \u2014\u00a0 | % | |||||||
| Fixed income, debt securities, or cash | 80\u00a0 | % | 100\u00a0 | % | |||||||
| Total | 100\u00a0 | % | 100\u00a0 | % |
| \u00a0 | 2020 | 2019 | |||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||||||||
| Accumulated benefit obligation | $ | 140,254\u00a0 | $ | 35,316\u00a0 | $ | 135,810\u00a0 | $ | 26,829\u00a0 | |||||||||||||||
| Fair value of plan assets | 115,568\u00a0 | 24,118\u00a0 | 107,832\u00a0 | 17,985\u00a0 |
| \u00a0 | 2020 | 2019 | |||||||||||||||||||||
| \u00a0 | U.S. | Foreign | U.S. | Foreign | |||||||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||||||||
| Projected benefit obligation | $ | 140,254\u00a0 | $ | 37,734\u00a0 | $ | 135,810\u00a0 | $ | 27,944\u00a0 | |||||||||||||||
| Fair value of plan assets | 115,568\u00a0 | 24,118\u00a0 | 107,832\u00a0 | 17,985\u00a0 |
| U.S. | Foreign | ||||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Expected contributions in 2021: | |||||||||||
| Expected employer contributions | $ | 2,363\u00a0 | $ | 886\u00a0 | |||||||
| Expected employee contributions | \u2014\u00a0 | \u2014\u00a0 | |||||||||
| Estimated future benefit payments reflecting expected future service for the years ending December\u00a031: | |||||||||||
| 2021 | 9,254\u00a0 | 1,102\u00a0 | |||||||||
| 2022 | 9,211\u00a0 | 1,087\u00a0 | |||||||||
| 2023 | 9,149\u00a0 | 1,229\u00a0 | |||||||||
| 2024 | 9,022\u00a0 | 2,763\u00a0 | |||||||||
| 2025 | 8,976\u00a0 | 1,330\u00a0 | |||||||||
| 2026-2030 | 42,021\u00a0 | 13,164\u00a0 |
| \u00a0 | (Dollars\u00a0in\u00a0Thousands) | ||||
| Balance as of December\u00a031, 2018 | $ | 1,528\u00a0 | |||
| Product warranty charges/adjustments | 1,033\u00a0 | ||||
| Payments and settlements | (726) | ||||
| Balance as of December\u00a031, 2019 | $ | 1,835\u00a0 | |||
| Product warranty charges/adjustments | 1,220\u00a0 | ||||
| Payments and settlements | (1,058) | ||||
| Balance as of December\u00a031, 2020 | $ | 1,997\u00a0 |
| \u00a0 | (Dollars\u00a0in\u00a0Thousands) | ||||
| Balance as of December\u00a031, 2018 | $ | 1,528\u00a0 | |||
| Product warranty charges/adjustments | 1,033\u00a0 | ||||
| Payments and settlements | (726) | ||||
| Balance as of December\u00a031, 2019 | $ | 1,835\u00a0 | |||
| Product warranty charges/adjustments | 1,220\u00a0 | ||||
| Payments and settlements | (1,058) | ||||
| Balance as of December\u00a031, 2020 | $ | 1,997\u00a0 |
| For the Year Ended December 31, | |||||||||||||||||
| \u00a0 | 2020 | 2019 | 2018 | ||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| U.S. | $ | 51,672\u00a0 | $ | 85,365\u00a0 | $ | (68,032) | |||||||||||
| Non-U.S. | 458,373\u00a0 | 757,462\u00a0 | 970,840\u00a0 | ||||||||||||||
| $ | 510,045\u00a0 | $ | 842,827\u00a0 | $ | 902,808\u00a0 |
| \u00a0 | For the Year Ended December 31, | ||||||||||||||||
| \u00a0 | 2020 | 2019 | 2018 | ||||||||||||||
| \u00a0 | |||||||||||||||||
| U.S. income taxes: | |||||||||||||||||
| Current | $ | (7,660) | $ | 16,589\u00a0 | $ | 787\u00a0 | |||||||||||
| Deferred | 27,822\u00a0 | 5,690\u00a0 | (52,145) | ||||||||||||||
| 20,162\u00a0 | 22,279\u00a0 | (51,358) | |||||||||||||||
| Non-U.S. income taxes: | |||||||||||||||||
| Current | 63,092\u00a0 | 64,134\u00a0 | 85,252\u00a0 | ||||||||||||||
| Deferred | (7,583) | 11,812\u00a0 | 15,026\u00a0 | ||||||||||||||
| 55,509\u00a0 | 75,946\u00a0 | 100,278\u00a0 | |||||||||||||||
| Total income tax expense (benefit) | $ | 75,671\u00a0 | $ | 98,225\u00a0 | $ | 48,920\u00a0 |
| For the Year Ended December 31, | |||||||||||||||||
| \u00a0 | 2020 | 2019 | 2018 | ||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| Tax at statutory U.S. federal rate | $ | 107,109\u00a0 | $ | 176,994\u00a0 | $ | 189,590\u00a0 | |||||||||||
| Impact of U.S. Tax Act - GILTI | 45,539\u00a0 | 65,531\u00a0 | 93,739\u00a0 | ||||||||||||||
| Impact of Tax Receivable Agreement | (4,429) | 713\u00a0 | 18,160\u00a0 | ||||||||||||||
| Valuation allowance | (980) | (14,548) | (93,125) | ||||||||||||||
| State taxes, net of federal tax benefit | 3,591\u00a0 | 4,231\u00a0 | 1,529\u00a0 | ||||||||||||||
| U.S. tax impact of foreign earnings (net of foreign tax credits) | 2,113\u00a0 | 2,181\u00a0 | 792\u00a0 | ||||||||||||||
| Establishment/resolution of uncertain tax positions | (78) | (1,293) | (345) | ||||||||||||||
| Adjustment for foreign income taxed at different rates | (38,464) | (76,922) | (95,822) | ||||||||||||||
| Foreign tax credits | (37,280) | (56,171) | (65,046) | ||||||||||||||
| Other | (1,450) | (2,491) | (552) | ||||||||||||||
| Provision (benefit) for income taxes | $ | 75,671\u00a0 | $ | 98,225\u00a0 | $ | 48,920\u00a0 |
| \u00a0 | As of December\u00a031, | ||||||||||
| \u00a0 | 2020 | 2019 | |||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Deferred tax assets: | |||||||||||
| Postretirement and other employee benefits | $ | 18,202\u00a0 | $ | 18,256\u00a0 | |||||||
| Foreign tax credit and other carryforwards | 37,101\u00a0 | 55,103\u00a0 | |||||||||
| Capitalized research and experimental costs | 3,897\u00a0 | 5,566\u00a0 | |||||||||
| Environmental reserves | 1,111\u00a0 | 1,110\u00a0 | |||||||||
| Inventory adjustments | 7,381\u00a0 | 14,863\u00a0 | |||||||||
| Long-term contract option amortization | 1,031\u00a0 | 1,080\u00a0 | |||||||||
| Provision for rationalization charges | 96\u00a0 | 232\u00a0 | |||||||||
| Mark- to- market Hedges | 3,552\u00a0 | 768\u00a0 | |||||||||
| Other | 3,646\u00a0 | 1,104\u00a0 | |||||||||
| Total gross deferred tax assets | 76,017\u00a0 | 98,082\u00a0 | |||||||||
| Less: valuation allowance | (12,773) | (13,736) | |||||||||
| Total deferred tax assets | 63,244\u00a0 | 84,346\u00a0 | |||||||||
| Deferred tax liabilities: | |||||||||||
| Fixed assets | $ | 54,485\u00a0 | $ | 56,659\u00a0 | |||||||
| Inventory | 8,573\u00a0 | 12,778\u00a0 | |||||||||
| Goodwill and acquired intangibles | 7,552\u00a0 | 6,996\u00a0 | |||||||||
| Other | 3,254\u00a0 | 2,468\u00a0 | |||||||||
| Total deferred tax liabilities | 73,864\u00a0 | 78,901\u00a0 | |||||||||
| Net deferred tax ( liability) asset | $ | (10,620) | $ | 5,445\u00a0 |
| (Dollars in thousands) | |||||
| Balance as of December 31, 2018 | $ | 58,446\u00a0 | |||
| \u00a0\u00a0\u00a0Credited to income | (14,548) | ||||
| \u00a0\u00a0\u00a0Changes attributable to write-off of underlying assets | (30,138) | ||||
| \u00a0\u00a0\u00a0Translation adjustment | (24) | ||||
| Balance as of December 31, 2019 | $ | 13,736\u00a0 | |||
| \u00a0\u00a0\u00a0Credited to income | (980) | ||||
| \u00a0\u00a0\u00a0Translation adjustment | 17\u00a0 | ||||
| Balance as of December 31, 2020 | $ | 12,773\u00a0 |
| (Dollars in thousands) | |||||
| Balance as of December 31, 2018 | $ | 1,990\u00a0 | |||
| \u00a0\u00a0\u00a0Settlements | (1,383) | ||||
| \u00a0\u00a0\u00a0Reductions for tax positions of prior years | (421) | ||||
| \u00a0\u00a0\u00a0Foreign currency impact | (2) | ||||
| Balance as of December 31, 2019 | $ | 184\u00a0 | |||
| \u00a0\u00a0\u00a0Lapse of statutes of limitations | (75) | ||||
| \u00a0\u00a0\u00a0Foreign currency impact | 16\u00a0 | ||||
| Balance as of December 31, 2020 | $ | 125\u00a0 |
| For the Year Ended December 31, | |||||||||||||||||
| \u00a0 | 2020 | 2019 | 2018 | ||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| U.S. | $ | 51,672\u00a0 | $ | 85,365\u00a0 | $ | (68,032) | |||||||||||
| Non-U.S. | 458,373\u00a0 | 757,462\u00a0 | 970,840\u00a0 | ||||||||||||||
| $ | 510,045\u00a0 | $ | 842,827\u00a0 | $ | 902,808\u00a0 |
| \u00a0 | For the Year Ended December 31, | ||||||||||||||||
| \u00a0 | 2020 | 2019 | 2018 | ||||||||||||||
| \u00a0 | |||||||||||||||||
| U.S. income taxes: | |||||||||||||||||
| Current | $ | (7,660) | $ | 16,589\u00a0 | $ | 787\u00a0 | |||||||||||
| Deferred | 27,822\u00a0 | 5,690\u00a0 | (52,145) | ||||||||||||||
| 20,162\u00a0 | 22,279\u00a0 | (51,358) | |||||||||||||||
| Non-U.S. income taxes: | |||||||||||||||||
| Current | 63,092\u00a0 | 64,134\u00a0 | 85,252\u00a0 | ||||||||||||||
| Deferred | (7,583) | 11,812\u00a0 | 15,026\u00a0 | ||||||||||||||
| 55,509\u00a0 | 75,946\u00a0 | 100,278\u00a0 | |||||||||||||||
| Total income tax expense (benefit) | $ | 75,671\u00a0 | $ | 98,225\u00a0 | $ | 48,920\u00a0 |
| For the Year Ended December 31, | |||||||||||||||||
| \u00a0 | 2020 | 2019 | 2018 | ||||||||||||||
| \u00a0 | (Dollars in thousands) | ||||||||||||||||
| Tax at statutory U.S. federal rate | $ | 107,109\u00a0 | $ | 176,994\u00a0 | $ | 189,590\u00a0 | |||||||||||
| Impact of U.S. Tax Act - GILTI | 45,539\u00a0 | 65,531\u00a0 | 93,739\u00a0 | ||||||||||||||
| Impact of Tax Receivable Agreement | (4,429) | 713\u00a0 | 18,160\u00a0 | ||||||||||||||
| Valuation allowance | (980) | (14,548) | (93,125) | ||||||||||||||
| State taxes, net of federal tax benefit | 3,591\u00a0 | 4,231\u00a0 | 1,529\u00a0 | ||||||||||||||
| U.S. tax impact of foreign earnings (net of foreign tax credits) | 2,113\u00a0 | 2,181\u00a0 | 792\u00a0 | ||||||||||||||
| Establishment/resolution of uncertain tax positions | (78) | (1,293) | (345) | ||||||||||||||
| Adjustment for foreign income taxed at different rates | (38,464) | (76,922) | (95,822) | ||||||||||||||
| Foreign tax credits | (37,280) | (56,171) | (65,046) | ||||||||||||||
| Other | (1,450) | (2,491) | (552) | ||||||||||||||
| Provision (benefit) for income taxes | $ | 75,671\u00a0 | $ | 98,225\u00a0 | $ | 48,920\u00a0 |
| \u00a0 | As of December\u00a031, | ||||||||||
| \u00a0 | 2020 | 2019 | |||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Deferred tax assets: | |||||||||||
| Postretirement and other employee benefits | $ | 18,202\u00a0 | $ | 18,256\u00a0 | |||||||
| Foreign tax credit and other carryforwards | 37,101\u00a0 | 55,103\u00a0 | |||||||||
| Capitalized research and experimental costs | 3,897\u00a0 | 5,566\u00a0 | |||||||||
| Environmental reserves | 1,111\u00a0 | 1,110\u00a0 | |||||||||
| Inventory adjustments | 7,381\u00a0 | 14,863\u00a0 | |||||||||
| Long-term contract option amortization | 1,031\u00a0 | 1,080\u00a0 | |||||||||
| Provision for rationalization charges | 96\u00a0 | 232\u00a0 | |||||||||
| Mark- to- market Hedges | 3,552\u00a0 | 768\u00a0 | |||||||||
| Other | 3,646\u00a0 | 1,104\u00a0 | |||||||||
| Total gross deferred tax assets | 76,017\u00a0 | 98,082\u00a0 | |||||||||
| Less: valuation allowance | (12,773) | (13,736) | |||||||||
| Total deferred tax assets | 63,244\u00a0 | 84,346\u00a0 | |||||||||
| Deferred tax liabilities: | |||||||||||
| Fixed assets | $ | 54,485\u00a0 | $ | 56,659\u00a0 | |||||||
| Inventory | 8,573\u00a0 | 12,778\u00a0 | |||||||||
| Goodwill and acquired intangibles | 7,552\u00a0 | 6,996\u00a0 | |||||||||
| Other | 3,254\u00a0 | 2,468\u00a0 | |||||||||
| Total deferred tax liabilities | 73,864\u00a0 | 78,901\u00a0 | |||||||||
| Net deferred tax ( liability) asset | $ | (10,620) | $ | 5,445\u00a0 |
| (Dollars in thousands) | |||||
| Balance as of December 31, 2018 | $ | 58,446\u00a0 | |||
| \u00a0\u00a0\u00a0Credited to income | (14,548) | ||||
| \u00a0\u00a0\u00a0Changes attributable to write-off of underlying assets | (30,138) | ||||
| \u00a0\u00a0\u00a0Translation adjustment | (24) | ||||
| Balance as of December 31, 2019 | $ | 13,736\u00a0 | |||
| \u00a0\u00a0\u00a0Credited to income | (980) | ||||
| \u00a0\u00a0\u00a0Translation adjustment | 17\u00a0 | ||||
| Balance as of December 31, 2020 | $ | 12,773\u00a0 |
| (Dollars in thousands) | |||||
| Balance as of December 31, 2018 | $ | 1,990\u00a0 | |||
| \u00a0\u00a0\u00a0Settlements | (1,383) | ||||
| \u00a0\u00a0\u00a0Reductions for tax positions of prior years | (421) | ||||
| \u00a0\u00a0\u00a0Foreign currency impact | (2) | ||||
| Balance as of December 31, 2019 | $ | 184\u00a0 | |||
| \u00a0\u00a0\u00a0Lapse of statutes of limitations | (75) | ||||
| \u00a0\u00a0\u00a0Foreign currency impact | 16\u00a0 | ||||
| Balance as of December 31, 2020 | $ | 125\u00a0 |
| \u00a0 | As of December 31, 2020 | As of December 31, 2019 | |||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Foreign currency translation adjustments, net of tax | $ | (2,725) | $ | (9,293) | |||||||
| Commodities, foreign currency and interest rate derivatives, net of tax | (16,916) | 1,932\u00a0 | |||||||||
| Total accumulated comprehensive (loss) income | $ | (19,641) | $ | (7,361) |
| \u00a0 | As of December 31, 2020 | As of December 31, 2019 | |||||||||
| \u00a0 | (Dollars\u00a0in\u00a0thousands) | ||||||||||
| Foreign currency translation adjustments, net of tax | $ | (2,725) | $ | (9,293) | |||||||
| Commodities, foreign currency and interest rate derivatives, net of tax | (16,916) | 1,932\u00a0 | |||||||||
| Total accumulated comprehensive (loss) income | $ | (19,641) | $ | (7,361) |
| For the Year Ended December 31, | |||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||
| Weighted average common shares outstanding for basic calculation | 267,916,483\u00a0 | 289,057,356\u00a0 | 297,748,327\u00a0 | ||||||||||||||
| Add: Effect of equity awards | 14,161\u00a0 | 17,245\u00a0 | 5,443\u00a0 | ||||||||||||||
| Weighted average common shares outstanding for diluted calculation | 267,930,644\u00a0 | 289,074,601\u00a0 | 297,753,770\u00a0 |
| For the Year Ended December 31, | |||||||||||||||||
| 2020 | 2019 | 2018 | |||||||||||||||
| Weighted average common shares outstanding for basic calculation | 267,916,483\u00a0 | 289,057,356\u00a0 | 297,748,327\u00a0 | ||||||||||||||
| Add: Effect of equity awards | 14,161\u00a0 | 17,245\u00a0 | 5,443\u00a0 | ||||||||||||||
| Weighted average common shares outstanding for diluted calculation | 267,930,644\u00a0 | 289,074,601\u00a0 | 297,753,770\u00a0 |
| 2020 | 2019 | |||||||||||||||||||||||||||||||||||||||||||||||||
| March 31 | June 30 | September 30 | December 31 | March 31 | June 30 | September 30 | December 31 | |||||||||||||||||||||||||||||||||||||||||||
| (Dollars in thousands, except per share amounts) | ||||||||||||||||||||||||||||||||||||||||||||||||||
| As Reported: | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Net Sales | $ | 318,646\u00a0 | $ | 280,718\u00a0 | $ | 286,987\u00a0 | $ | 338,010\u00a0 | $ | 474,994\u00a0 | $ | 480,390\u00a0 | $ | 420,797\u00a0 | $ | 414,612\u00a0 | ||||||||||||||||||||||||||||||||||
| Gross profit | 179,729\u00a0 | 150,118\u00a0 | 155,125\u00a0 | 175,525\u00a0 | 279,470\u00a0 | 283,343\u00a0 | 242,300\u00a0 | 235,290\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Research and development | 712\u00a0 | 710\u00a0 | 650\u00a0 | 1,903\u00a0 | 637\u00a0 | 713\u00a0 | 611\u00a0 | 723\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Selling and administrative expenses | 14,932\u00a0 | 16,001\u00a0 | 19,062\u00a0 | 17,918\u00a0 | 15,226\u00a0 | 15,394\u00a0 | 15,708\u00a0 | 17,346\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Other expense (income), net | (3,314) | 311\u00a0 | 694\u00a0 | 5,639\u00a0 | 467\u00a0 | 863\u00a0 | (688) | 4,561\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Related party Tax Receivable Agreement (benefit) expense | (3,346) | \u2014\u00a0 | \u2014\u00a0 | (17,744) | \u2014\u00a0 | \u2014\u00a0 | \u2014\u00a0 | 3,393\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Interest Expense | 25,672\u00a0 | 20,880\u00a0 | 22,474\u00a0 | 29,048\u00a0 | 33,700\u00a0 | 32,969\u00a0 | 31,803\u00a0 | 28,859\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Interest Income | (1,141) | (348) | (93) | (168) | (414) | (731) | (1,765) | (1,799) | ||||||||||||||||||||||||||||||||||||||||||
| Net income | 122,268\u00a0 | 92,776\u00a0 | 94,234\u00a0 | 125,096\u00a0 | 197,436\u00a0 | 196,368\u00a0 | 175,876\u00a0 | 174,922\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Net income per share | $ | 0.45\u00a0 | $ | 0.35\u00a0 | $ | 0.35\u00a0 | $ | 0.47\u00a0 | $ | 0.68\u00a0 | $ | 0.68\u00a0 | $ | 0.61\u00a0 | $ | 0.61\u00a0 |
| 2020 | 2019 | |||||||||||||||||||||||||||||||||||||||||||||||||
| March 31 | June 30 | September 30 | December 31 | March 31 | June 30 | September 30 | December 31 | |||||||||||||||||||||||||||||||||||||||||||
| (Dollars in thousands, except per share amounts) | ||||||||||||||||||||||||||||||||||||||||||||||||||
| As Reported: | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Net Sales | $ | 318,646\u00a0 | $ | 280,718\u00a0 | $ | 286,987\u00a0 | $ | 338,010\u00a0 | $ | 474,994\u00a0 | $ | 480,390\u00a0 | $ | 420,797\u00a0 | $ | 414,612\u00a0 | ||||||||||||||||||||||||||||||||||
| Gross profit | 179,729\u00a0 | 150,118\u00a0 | 155,125\u00a0 | 175,525\u00a0 | 279,470\u00a0 | 283,343\u00a0 | 242,300\u00a0 | 235,290\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Research and development | 712\u00a0 | 710\u00a0 | 650\u00a0 | 1,903\u00a0 | 637\u00a0 | 713\u00a0 | 611\u00a0 | 723\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Selling and administrative expenses | 14,932\u00a0 | 16,001\u00a0 | 19,062\u00a0 | 17,918\u00a0 | 15,226\u00a0 | 15,394\u00a0 | 15,708\u00a0 | 17,346\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Other expense (income), net | (3,314) | 311\u00a0 | 694\u00a0 | 5,639\u00a0 | 467\u00a0 | 863\u00a0 | (688) | 4,561\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Related party Tax Receivable Agreement (benefit) expense | (3,346) | \u2014\u00a0 | \u2014\u00a0 | (17,744) | \u2014\u00a0 | \u2014\u00a0 | \u2014\u00a0 | 3,393\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Interest Expense | 25,672\u00a0 | 20,880\u00a0 | 22,474\u00a0 | 29,048\u00a0 | 33,700\u00a0 | 32,969\u00a0 | 31,803\u00a0 | 28,859\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Interest Income | (1,141) | (348) | (93) | (168) | (414) | (731) | (1,765) | (1,799) | ||||||||||||||||||||||||||||||||||||||||||
| Net income | 122,268\u00a0 | 92,776\u00a0 | 94,234\u00a0 | 125,096\u00a0 | 197,436\u00a0 | 196,368\u00a0 | 175,876\u00a0 | 174,922\u00a0 | ||||||||||||||||||||||||||||||||||||||||||
| Net income per share | $ | 0.45\u00a0 | $ | 0.35\u00a0 | $ | 0.35\u00a0 | $ | 0.47\u00a0 | $ | 0.68\u00a0 | $ | 0.68\u00a0 | $ | 0.61\u00a0 | $ | 0.61\u00a0 |