SEGMENT INFORMATION (Details 1) - USD ($) $ in Millions	3 Months Ended		72 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022
Sales [Abstract]
Sales	$ 2,461.4	$ 1,918.8
Income before taxes:
Income (loss) before taxes	523.6	306.1
Corporate/Other:
Environmental expense	5.6	2.5
Restructuring charges	(3.1)	(6.9)	$ (274.4)
Interest expense	(32.9)	(84.5)
Interest income	0.4	0.1
Non-operating pension income	9.6	9.3
Corporate/other
Corporate/Other:
Environmental expense	5.6	0.3
Other corporate and unallocated costs	(30.3)	(33.0)
Restructuring charges	(3.1)	(6.9)
Chlor Alkali Products and Vinyls
Sales [Abstract]
Sales	1,245.2	867.0
Income before taxes:
Income (loss) before taxes	328.6	271.1
Epoxy
Sales [Abstract]
Sales	789.5	662.6
Income before taxes:
Income (loss) before taxes	138.0	65.2
Winchester
Sales [Abstract]
Sales	426.7	389.2
Income before taxes:
Income (loss) before taxes	$ 118.9	$ 85.1