SEGMENT INFORMATION (Details 1) - USD ($) $ in Millions	3 Months Ended		96 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024
Sales [Abstract]
Sales	$ 1,635.3	$ 1,844.3
Income before Taxes
Income (loss) before taxes	60.3	194.8
Corporate/Other:
Environmental expense	5.8	3.2
Restructuring charges	(8.3)	(60.9)	$ (201.5)
Other operating income	0.2	0.5
Interest expense	(44.6)	(42.4)
Interest income	0.8	1.1
Non-operating pension income	6.8	5.7
Corporate/other
Corporate/Other:
Environmental expense	5.8	3.2
Other corporate and unallocated costs	(25.8)	(34.3)
Restructuring charges	(8.3)	(60.9)
Chlor Alkali Products and Vinyls
Sales [Abstract]
Sales	884.6	1,117.1
Income before Taxes
Income (loss) before taxes	76.6	245.9
Epoxy
Sales [Abstract]
Sales	341.3	360.7
Income before Taxes
Income (loss) before taxes	(11.8)	21.4
Winchester
Sales [Abstract]
Sales	409.4	366.5
Income before Taxes
Income (loss) before taxes	$ 72.2	$ 61.0