COMMITMENTS AND CONTINGENCIES - Purchase Commitments (Details)	9 Months Ended
	Sep. 30, 2025
Maximum
COMMITMENTS AND CONTINGENCIES
Purchase commitment period	4 years
Minimum
COMMITMENTS AND CONTINGENCIES
Purchase commitment period	1 year

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.

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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/exampleRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Trinseo PLC 10-Q