GOODWILL AND INTANGIBLE ASSETS (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 1,420.6	$ 1,420.2	$ 2,119.7
Goodwill, Impairment Loss	0.0	(699.8)	0.0
Foreign currency translation adjustment	0.4	0.3
Chlor Alkali Products and Vinyls
Goodwill [Line Items]
Goodwill	1,275.6	1,275.3	1,832.7
Goodwill, Impairment Loss		557.6
Foreign currency translation adjustment	0.3	0.2
Epoxy
Goodwill [Line Items]
Goodwill	145.0	144.9	$ 287.0
Goodwill, Impairment Loss		142.2
Foreign currency translation adjustment	$ 0.1	$ 0.1