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Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Aug. 06, 2020 | Sep. 30, 2020 | Sep. 30, 2020
Environmental Contingency |  |  |
Environmental accrual increased during the period |  | $ 3.8 |
Environmental accrual |  | 20.7 | $ 20.7
Expected period related to remediation expenditures for environmental contingencies period |  |  | 30 years
Potential increase in environmental costs |  | 11.6 | $ 11.6
Time period within which recorded estimate of its obligation may change |  |  | 12 months
Comprehensive Environmental Response, Compensation and Liability Act |  |  |
Environmental Contingency |  |  |
Environmental accrual |  | 1.9 | $ 1.9
Environmental accrual remained |  | $ 1.2 | $ 1.2
Comprehensive Environmental Response, Compensation and Liability Act | Administrative Settlement Agreement |  |  |
Environmental Contingency |  |  |
Consent for Removal Actions, first phase estimated completion period | 3 months |  |
Minimum |  |  |
Environmental Contingency |  |  |
Period for final feasibility study |  |  | 12 months
Maximum |  |  |
Environmental Contingency |  |  |
Period for final feasibility study |  |  | 24 months

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