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Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions |  |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
May 22, 2019 | Jun. 18, 2018 | May 31, 2017 | Dec. 31, 2020 | Dec. 31, 2019
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Environmental loss contingency accrual |  |  |  | $ 53 | $ 47
Minimum [Member] |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Environmental Exit Costs, Reasonably Possible Additional Loss |  |  |  | 65 |
Maximum [Member] |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Environmental Exit Costs, Reasonably Possible Additional Loss |  |  |  | $ 130 |
Avient [Member] |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties | 100.00% |  |  |  |
Avient [Member] | Pending Litigation [Member] |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties |  |  |  | 100.00% |
Loss Contingency, Damages Sought, Value |  |  | $ 11 |  |
Environmental Protection Agency [Member] | Operation and Maintenance [Member] |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Environmental Remediation Expense |  | $ 107 |  |  |
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Minimum [Member] |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Environmental Exit Costs, Anticipated Cost |  |  |  | $ 1 |
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Maximum [Member] |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |
Environmental Exit Costs, Anticipated Cost |  |  |  | $ 3 |

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- Definition Total anticipated costs associated with remediation, site restoration, postclosure, monitoring commitments, or other exit costs that may occur on the sale, disposal, or abandonment of a particular property resulting from unanticipated contamination of the assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q4) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 + Details
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