GOODWILL AND INTANGIBLE ASSETS (Details 1) - USD ($) $ in Millions |
9 Months Ended | ||||
|---|---|---|---|---|---|
Sep. 30, 2025 |
Sep. 30, 2024 |
Sep. 30, 2021 |
Dec. 31, 2024 |
Dec. 31, 2023 |
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| Goodwill [Line Items] | |||||
| Goodwill | $ 1,425.9 | $ 1,423.7 | $ 1,423.6 | $ 1,424.0 | |
| Goodwill, Period Increase (Decrease) | 2.4 | (0.3) | |||
| Goodwill, Foreign Currency Translation Gain (Loss) | (0.1) | ||||
| Chlor Alkali Products and Vinyls | |||||
| Goodwill [Line Items] | |||||
| Goodwill | 1,276.3 | 1,276.1 | 1,276.4 | 1,276.1 | |
| Goodwill, Period Increase (Decrease) | 0.0 | 0.0 | |||
| Goodwill, Foreign Currency Translation Gain (Loss) | (0.1) | ||||
| Goodwill, Impairment Loss | $ 557.6 | ||||
| Epoxy | |||||
| Goodwill [Line Items] | |||||
| Goodwill | 144.8 | 145.2 | 144.8 | 145.2 | |
| Goodwill, Period Increase (Decrease) | 0.0 | 0.0 | |||
| Goodwill, Foreign Currency Translation Gain (Loss) | 0.0 | ||||
| Goodwill, Impairment Loss | $ 142.2 | ||||
| Winchester | |||||
| Goodwill [Line Items] | |||||
| Goodwill | 4.8 | 2.4 | $ 2.4 | $ 2.7 | |
| Goodwill, Period Increase (Decrease) | 2.4 | $ (0.3) | |||
| Goodwill, Foreign Currency Translation Gain (Loss) | $ 0.0 | ||||
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- Definition Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of foreign currency translation gain (loss) which increases (decreases) asset representing future economic benefit from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase (decrease) of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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