Freeport, TX chlor alkali production capacity reduction announced on December 11, 2019.

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Reduction of diaphragm-grade chlor alkali capacity at our McIntosh, AL facility announced in 2021.

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Total chlor alkali product segment production capacity decrease announced on March 21, 2016

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RESTRUCTURING CHARGES (Details 1) $ in Millions	3 Months Ended						9 Months Ended		31 Months Ended	32 Months Ended	46 Months Ended	90 Months Ended
RESTRUCTURING CHARGES (Details 1) $ in Millions	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Oct. 21, 2021 T	Dec. 11, 2019 T	Mar. 21, 2016 T
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 11.9	$ 19.2	$ 60.9	$ 7.6	$ 3.6	$ 3.1	$ 92.0	$ 14.3				$ 388.6
Inception to date Amounts Utilized (cash)												184.5
Inception to date Amounts Utilized (non-cash)												158.0
Epoxy Optimization Plan \| Epoxy
Restructuring Cost and Reserve [Line Items]
Restructuring charges	8.6						79.7					87.7
Additional restructuring and related expected cost	45.0						45.0		$ 45.0	$ 45.0	$ 45.0	45.0
McIntosh Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.7			5.5			4.6	7.1	18.5
Additional restructuring and related expected cost	25.0						25.0		25.0	25.0	25.0	25.0
McIntosh Restructuring Capacity Reduction \| T													400,000
Freeport 2021 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.7			0.4			2.8	1.9		11.9
Additional restructuring and related expected cost	15.0						15.0		15.0	15.0	15.0	15.0
Freeport 2019 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.9			$ 1.7			4.9	4.9			77.5
Additional restructuring and related expected cost	25.0						25.0		25.0	25.0	25.0	25.0
Freeport Chlor Alkali Capacity Reduction \| T														230,000
Chlor Alkali 2016 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges								$ 0.4				182.7
Additional restructuring and related expected cost	$ 0.0						$ 0.0		$ 0.0	$ 0.0	$ 0.0	$ 0.0
Total Product Segment Production Capacity Decrease \| T															433,000