GOODWILL AND OTHER INTANGIBLE ASSETS (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2015 USD ($) segment	Dec. 31, 2014 USD ($)
Goodwill [Line Items]
Goodwill impairment charge	$ (847.8)	$ (847.8)
GOODWILL AND OTHER INTANGIBLE ASSETS
Number of segments that contain reporting units with goodwill and intangible assets | segment		2
Changes made to goodwill by reportable segment
Gross goodwill at the beginning of the period	1,081.7	$ 1,081.7	$ 1,951.0
Foreign currency translation adjustment		(21.5)
Accumulated impairment losses at the end of the period	(210.0)	(210.0)	(210.0)
Net goodwill at the end of the period	871.7	871.7	1,741.0
Goodwill impairment charge	(847.8)	(847.8)
Trade names
Changes made to goodwill by reportable segment
Indefinite-lived intangible assets, net of cumulative translation adjustment	5.9	5.9	6.0
Chlorovinyls
Goodwill [Line Items]
Goodwill impairment charge	(847.8)	(847.8)
Changes made to goodwill by reportable segment
Gross goodwill at the beginning of the period	921.5	921.5	1,790.8
Foreign currency translation adjustment		(21.5)
Accumulated impairment losses at the end of the period	(59.6)	(59.6)	(59.6)
Net goodwill at the end of the period	861.9	861.9	1,731.2
Goodwill impairment charge	(847.8)	(847.8)
Building Products
Changes made to goodwill by reportable segment
Gross goodwill at the beginning of the period	160.2	160.2	160.2
Accumulated impairment losses at the end of the period	(150.4)	(150.4)	(150.4)
Net goodwill at the end of the period	$ 9.8	$ 9.8	$ 9.8
Minimum | Compound, mouldings and siding reporting unit
Goodwill [Line Items]
Percentage that estimated fair values exceeded carrying values for the reporting unit	10.00%	10.00%