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Commitments and Contingencies - Environmental (Details) $ in Millions | 1 Months Ended | 12 Months Ended | 36 Months Ended |
--- | --- | --- | --- | ---
Feb. 28, 2022 USD ($) MMcf | Jan. 31, 2018 USD ($) unilateral_administrative_order | Sep. 30, 2014 USD ($) property | Dec. 25, 2021 USD ($) | Dec. 26, 2020 USD ($) | Dec. 28, 2019 USD ($) | Dec. 25, 2021 USD ($) | Dec. 28, 2019 USD ($) | Dec. 25, 2021 smelter_site | Dec. 25, 2021 potentially_responsible_party
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Environmental expense |  |  |  | $ 5.0 | $ 4.2 | $ 1.7 |  |  |  |
Environmental reserves |  |  |  | 27.4 | $ 24.0 |  | $ 27.4 |  |  |
Expected environmental expenditures for 2022 |  |  |  | 9.6 |  |  | 9.6 |  |  |
Expected environmental expenditures for 2023 |  |  |  | 3.1 |  |  | 3.1 |  |  |
Expected environmental expenditures for 2024 |  |  |  | 0.8 |  |  | 0.8 |  |  |
Expected environmental expenditures for 2025 |  |  |  | 0.9 |  |  | 0.9 |  |  |
Expected environmental expenditures for 2026 |  |  |  | 0.7 |  |  | 0.7 |  |  |
Expected environmental expenditures after 2026 |  |  |  | $ 12.3 |  |  | 12.3 |  |  |
East La Harpe |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Number of parties involved in settlement negotiations |  |  |  |  |  |  |  |  | 3 | 2
Southeast Kansas Sites | Subsequent Event |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Environmental reserves | $ 5.6 |  |  |  |  |  |  |  |  |
Geographic boundary of sites | MMcf | 50 |  |  |  |  |  |  |  |  |
Shasta Area Mine Sites |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Period of permit, implementation of Best Management Practices |  |  |  | 10 years |  |  |  |  |  |
Environmental remediation expense spending |  |  |  |  |  |  |  | $ 1.5 |  |
Estimated number of years until mitigation resolution |  |  |  | 30 years |  |  |  |  |  |
Shasta Area Mine Sites | Minimum |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Mitigation estimates |  |  |  | $ 14.0 |  |  |  |  |  |
Shasta Area Mine Sites | Maximum |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Mitigation estimates |  |  |  | 16.0 |  |  |  |  |  |
Lead Refinery Site |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Environmental expense |  |  |  |  |  |  | 0.5 |  |  |
Lead Refinery Site [Abstract] |  |  |  |  |  |  |  |  |  |
EPA's estimated cost of site remediation |  |  | $ 26.0 |  |  |  |  |  |  |
Number of surrounding properties | property |  |  | 300 |  |  |  |  |  |  |
Site contingency, financial guarantee |  |  |  | $ 1.0 |  |  | 1.0 |  |  |
Lead Refinery Site | Non operating Properties |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Estimated number of years until mitigation resolution |  |  |  | 15 years |  |  |  |  |  |
Lead Refinery Site | Minimum |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Mitigation estimates |  |  |  | $ 1.6 |  |  |  |  |  |
Lead Refinery Site | Maximum |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Mitigation estimates |  |  |  | 2.3 |  |  |  |  |  |
Lead Refinery NPL Site |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Environmental reserves |  | $ 4.5 |  |  |  |  |  |  |  |
Lead Refinery Site [Abstract] |  |  |  |  |  |  |  |  |  |
Number of UAOs issued | unilateral_administrative_order |  | 2 |  |  |  |  |  |  |  |
Site contingency, total costs |  | $ 25.0 |  |  |  |  |  |  |  |
Site contingency, amount agreed upon to pay PRPs for past costs |  | 2.0 |  |  |  |  |  |  |  |
Possible further payments for ongoing work by PRPs |  | $ 0.7 |  |  |  |  |  |  |  |
Payments for unilateral administrative orders |  |  |  | 7.6 |  |  |  |  |  |
Loss contingency accrual |  |  |  | 3.3 |  |  | $ 3.3 |  |  |
Mueller Copper Tube Products, Inc. | Minimum |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Mitigation estimates |  |  |  | 0.7 |  |  |  |  |  |
Mueller Copper Tube Products, Inc. | Maximum |  |  |  |  |  |  |  |  |  |
Site Contingency [Line Items] |  |  |  |  |  |  |  |  |  |
Mitigation estimates |  |  |  | $ 0.9 |  |  |  |  |  |

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