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

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RESTRUCTURING CHARGES (Details) $ in Millions	6 Months Ended	12 Months Ended			33 Months Ended	34 Months Ended	35 Months Ended	49 Months Ended	93 Months Ended
RESTRUCTURING CHARGES (Details) $ in Millions	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Mar. 15, 2021 T	Dec. 31, 2020 USD ($)	Dec. 11, 2019 T	Mar. 21, 2016 T
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 89.6	$ 25.3	$ 27.9					$ 386.2
Restructuring and Related Cost, Incurred Cost									200.7
Restructuring Reserve, Settled without Cash									158.0
Accrued Restructuring Costs	$ 27.5	27.5	13.6	12.3	$ 27.5	$ 27.5	$ 27.5	$ 27.5	27.5		$ 3.5
Stade Plan \| Epoxy
Restructuring Cost and Reserve [Line Items]
Restructuring charges	81.4	73.4	8.0
Additional restructuring and related expected cost	25.0	25.0			25.0	25.0	25.0	25.0	25.0
McIntosh Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4.7	8.3	5.6		18.6
Additional restructuring and related expected cost	20.0	20.0			20.0	20.0	20.0	20.0	20.0
Total Product Segment Production Capacity Decrease \| T										400,000
Productivity Plan \| Corporate and Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges				10.3	10.3
Additional restructuring and related expected cost	0.0	0.0			0.0	0.0	0.0	0.0	0.0
Freeport 2021 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4.0	2.6	6.5			13.1
Additional restructuring and related expected cost	10.0	10.0			10.0	10.0	10.0	10.0	10.0
Freeport 2019 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		7.5	6.0	3.9				80.1
Additional restructuring and related expected cost	15.0	15.0			15.0	15.0	15.0	15.0	15.0
Total Product Segment Production Capacity Decrease \| T												230,000
Chlor Alkali 2016 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 0.4	$ 1.6					182.7
Additional restructuring and related expected cost	$ 0.0	$ 0.0			$ 0.0	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Total Product Segment Production Capacity Decrease \| T													433,000