GOODWILL AND INTANGIBLE ASSETS (Details 1) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill	$ 1,421.0	$ 1,421.2	$ 1,420.9	$ 1,420.6
Goodwill, Foreign Currency Translation Gain (Loss)	0.1	0.6
Chlor Alkali Products and Vinyls
Goodwill [Line Items]
Goodwill	1,275.9	1,276.1	1,275.8	1,275.6
Goodwill, Foreign Currency Translation Gain (Loss)	0.1	0.5
Epoxy
Goodwill [Line Items]
Goodwill	145.1	145.1	$ 145.1	$ 145.0
Goodwill, Foreign Currency Translation Gain (Loss)	$ 0.0	$ 0.1