SEGMENT INFORMATION (Details 1) - USD ($) $ in Millions	3 Months Ended						9 Months Ended		90 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023
Sales [Abstract]
Sales	$ 1,671.4			$ 2,321.7			$ 5,218.4	$ 7,399.2
Income (loss) before taxes:
Income (loss) before taxes	126.7			367.9			499.4	1,432.2
Corporate/Other:
Environmental expense	6.9			7.4			23.1	18.0
Restructuring charges	(11.9)	$ (19.2)	$ (60.9)	(7.6)	$ (3.6)	$ (3.1)	(92.0)	(14.3)	$ (388.6)
Other operating (expense) income	(0.3)			13.0			27.2	16.3
Interest expense	(46.2)			(36.0)			(133.9)	(103.4)
Interest income	1.0			0.5			3.2	1.2
Non-operating pension income	5.9			9.9			17.0	29.0
Gain on the sale of domestic private trucking fleet and operations
Corporate/Other:
Other operating (expense) income							27.0
Gain for the sale of two former manufacturing facilities
Corporate/Other:
Other operating (expense) income								13.0
Corporate/other
Corporate/Other:
Environmental expense	6.9			7.4			23.1	18.0
Other corporate and unallocated costs	(22.9)			(27.5)			(79.6)	(92.8)
Restructuring charges	(11.9)			(7.6)			(92.0)	(14.3)
Chlor Alkali Products and Vinyls
Sales [Abstract]
Sales	969.6			1,263.5			3,089.0	3,912.2
Income (loss) before taxes:
Income (loss) before taxes	172.3			253.9			598.3	929.0
Epoxy
Sales [Abstract]
Sales	321.6			644.1			1,016.1	2,206.3
Income (loss) before taxes:
Income (loss) before taxes	(28.8)			80.1			(7.9)	358.0
Winchester
Sales [Abstract]
Sales	380.2			414.1			1,113.3	1,280.7
Income (loss) before taxes:
Income (loss) before taxes	$ 64.5			$ 89.0			$ 190.2	$ 327.2