RESTRUCTURING CHARGES (Details 2) - USD ($) $ in Millions	6 Months Ended	12 Months Ended			33 Months Ended	34 Months Ended	35 Months Ended	49 Months Ended	93 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 89.6	$ 25.3	$ 27.9					$ 386.2
Write-off of Equipment and Facility
Restructuring Cost and Reserve [Line Items]
Restructuring charges		17.7	3.3	0.0					158.0
Employee Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		8.4	7.4	10.3					34.9
Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		34.4	13.5	11.6					113.1
Employee Relocation Cost
Restructuring Cost and Reserve [Line Items]
Restructuring charges									1.7
Lease and Other Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		29.1	1.1	6.0					78.5
McIntosh Plan | Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4.7	8.3	5.6		$ 18.6
McIntosh Plan | Chlor Alkali Products and Vinyls | Write-off of Equipment and Facility
Restructuring Cost and Reserve [Line Items]
Restructuring charges						2.7
McIntosh Plan | Chlor Alkali Products and Vinyls | Employee Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges						0.0
McIntosh Plan | Chlor Alkali Products and Vinyls | Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges						9.5
McIntosh Plan | Chlor Alkali Products and Vinyls | Employee Relocation Cost
Restructuring Cost and Reserve [Line Items]
Restructuring charges						0.0
McIntosh Plan | Chlor Alkali Products and Vinyls | Lease and Other Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges						$ 6.4
Freeport 2021 Plan | Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4.0	2.6	6.5			$ 13.1
Freeport 2021 Plan | Chlor Alkali Products and Vinyls | Write-off of Equipment and Facility
Restructuring Cost and Reserve [Line Items]
Restructuring charges							0.0
Freeport 2021 Plan | Chlor Alkali Products and Vinyls | Employee Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges							0.0
Freeport 2021 Plan | Chlor Alkali Products and Vinyls | Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges							13.1
Freeport 2021 Plan | Chlor Alkali Products and Vinyls | Employee Relocation Cost
Restructuring Cost and Reserve [Line Items]
Restructuring charges							0.0
Freeport 2021 Plan | Chlor Alkali Products and Vinyls | Lease and Other Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges							$ 0.0
Freeport 2019 Plan | Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		7.5	6.0	3.9				$ 80.1
Freeport 2019 Plan | Chlor Alkali Products and Vinyls | Write-off of Equipment and Facility
Restructuring Cost and Reserve [Line Items]
Restructuring charges								58.9
Freeport 2019 Plan | Chlor Alkali Products and Vinyls | Employee Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges								2.1
Freeport 2019 Plan | Chlor Alkali Products and Vinyls | Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges								19.1
Freeport 2019 Plan | Chlor Alkali Products and Vinyls | Employee Relocation Cost
Restructuring Cost and Reserve [Line Items]
Restructuring charges								0.0
Freeport 2019 Plan | Chlor Alkali Products and Vinyls | Lease and Other Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges								$ 0.0
Chlor Alkali 2016 Plan | Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0.4	1.6					182.7
Chlor Alkali 2016 Plan | Chlor Alkali Products and Vinyls | Write-off of Equipment and Facility
Restructuring Cost and Reserve [Line Items]
Restructuring charges									78.1
Chlor Alkali 2016 Plan | Chlor Alkali Products and Vinyls | Employee Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges									6.7
Chlor Alkali 2016 Plan | Chlor Alkali Products and Vinyls | Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges									53.2
Chlor Alkali 2016 Plan | Chlor Alkali Products and Vinyls | Employee Relocation Cost
Restructuring Cost and Reserve [Line Items]
Restructuring charges									1.7
Chlor Alkali 2016 Plan | Chlor Alkali Products and Vinyls | Lease and Other Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges									$ 43.0
Stade Plan | Epoxy
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 81.4	73.4	$ 8.0
Stade Plan | Epoxy | Write-off of Equipment and Facility
Restructuring Cost and Reserve [Line Items]
Restructuring charges		18.3
Stade Plan | Epoxy | Employee Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		15.8
Stade Plan | Epoxy | Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		18.2
Stade Plan | Epoxy | Employee Relocation Cost
Restructuring Cost and Reserve [Line Items]
Restructuring charges		0.0
Stade Plan | Epoxy | Lease and Other Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 29.1
Productivity Plan | Corporate and Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 10.3	$ 10.3
Productivity Plan | Corporate and Other | Write-off of Equipment and Facility
Restructuring Cost and Reserve [Line Items]
Restructuring charges					0.0
Productivity Plan | Corporate and Other | Employee Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges					10.3
Productivity Plan | Corporate and Other | Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges					0.0
Productivity Plan | Corporate and Other | Employee Relocation Cost
Restructuring Cost and Reserve [Line Items]
Restructuring charges					0.0
Productivity Plan | Corporate and Other | Lease and Other Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges					$ 0.0