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Financial Instruments and Derivatives - Additional Information (Details) gal in Millions, MMBTU in Millions | 1 Months Ended | 3 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Mar. 31, 2020 USD ($) | Apr. 04, 2021 USD ($) MMBTU T gal | Mar. 29, 2020 USD ($) | Apr. 28, 2021 USD ($) | Apr. 07, 2021 USD ($) | Dec. 31, 2020 USD ($) | Jan. 31, 2020 USD ($)
Derivative [Line Items] |  |  |  |  |  |  |
Fair value of commodity cash flow hedges, gain (loss) |  | $ 1,179,000 |  |  |  | $ (647,000) |
Commodity gain (loss) expected to be reclassified to the income statement during the next 12 months |  | 953,000 |  |  |  |  |
Fair value of foreign currency cash flow hedges, gain (loss) |  | 311,000 |  |  |  | 555,000 |
Foreign currency gain (loss) expected to be reclassified to the income statement during the next 12 months |  | 311,000 |  |  |  |  |
Proceeds from cross-currency swap |  | 0 | $ 14,480,000 |  |  |  |
Total fair value of other derivatives not designated as hedging instruments |  | 771,000 |  |  |  | 599,000 |
1.0% Euro loan due May 2021 |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Outstanding balance |  | $ 176,100,000 |  |  |  |  |
Interest rate (percent) |  | 1.00% |  |  |  |  |
Debt principal |  | $ 150,000,000 |  |  |  |  |
Pending offer | Subsequent Event | 5.75% debentures due November 2040 | Notes |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Amount offered to be repurchased |  |  |  | $ 300,000,000 |  |  |
Outstanding balance |  |  |  | $ 600,000,000 |  |  |
Interest rate (percent) |  |  |  | 5.75% |  |  |
Early tender premium per thousand dollar principal |  |  |  | $ 50 |  |  |
Percentage of fair value of notes in excess of carrying amount (percent) |  |  |  | 25.00% |  |  |
Natural Gas Swaps |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Approximate amount of commodity covered by swap contracts outstanding (in MMBTUs) | MMBTU |  | 7.1 |  |  |  |  |
Anticipated usage percentage covered by a swap contract for the current fiscal year (percent) |  | 67.00% |  |  |  |  |
Anticipated usage percentage covered by a swap contract for the next fiscal year (percent) |  | 41.00% |  |  |  |  |
Aluminum Swaps |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Anticipated usage percentage covered by a swap contract for the current fiscal year (percent) |  | 55.00% |  |  |  |  |
Approximate amount of commodity covered by swap contracts outstanding (in tons) | T |  | 2,763 |  |  |  |  |
Cross-currency swap |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  |  |  |  |  |  | $ 250,000,000
Proceeds from cross-currency swap | $ 14,480,000 |  |  |  |  |  |
Tax provision on foreign currency translation gain | $ 7,581,000 |  |  |  |  |  |
Cross-currency swap | Subsequent Event |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  |  |  |  | $ 150,000,000 |  |
Diesel Swaps |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Gallons of diesel fuel covered under contract (gallons) | gal |  | 0.5 |  |  |  |  |
Forward contracts |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Fair value of foreign currency cash flow hedges, gain (loss) |  | $ (289,000) |  |  |  | $ 47,000 |
Foreign currency gain (loss) expected to be reclassified to the income statement during the next 12 months |  | (266,000) |  |  |  |  |
Foreign currency gain (loss) reclassified to the income statement |  | $ 13,000 |  |  |  |  |
Reverse Treasury Lock Contract | Subsequent Event |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  |  |  | $ 100,000,000 |  |  |

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