RESTRUCTURING CHARGES (Details 1) $ in Millions	3 Months Ended		37 Months Ended	38 Months Ended	52 Months Ended	96 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2024 USD ($)	Oct. 21, 2021 T	Dec. 11, 2019 T
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 8.3	$ 60.9				$ 201.5
Inception to date Amounts Utilized (cash)						104.1
Inception to date Amounts Utilized (non-cash)						79.9
Epoxy Optimization Plan | Epoxy
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3.5	57.8				84.9
Additional restructuring and related expected cost	20.0		$ 20.0	$ 20.0	$ 20.0	20.0
McIntosh Plan | Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.9	1.4	20.5
Additional restructuring and related expected cost	20.0		20.0	20.0	20.0	20.0
McIntosh Restructuring Capacity Reduction | T							400,000
Freeport 2021 Plan | Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.4	0.7		13.5
Additional restructuring and related expected cost	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	2.5	$ 1.0			82.6
Additional restructuring and related expected cost	$ 15.0		$ 15.0	$ 15.0	$ 15.0	$ 15.0
Freeport Chlor Alkali Capacity Reduction | T								230,000