GOODWILL AND OTHER INTANGIBLE ASSETS (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	$ 1,255.4		$ 1,255.4
Accumulated impairment charges	(2.9)		(2.6)
Accumulated amortization:	(168.6)		(152.0)
Foreign currency translation adjustment:	(16.4)		(14.2)
Net carrying amounts	1,067.5		1,086.6
Amortization expense for the definite-lived intangible assets	16.6	16.8
Total definite-lived intangible asset estimated annual amortization expense for the next five fiscal years
Year one	66.4
Year two	66.4
Year three	66.4
Year four	66.4
Year five	66.4
Customer relationships
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	1,174.5		1,174.5
Accumulated impairment charges	(2.9)		(2.6)
Accumulated amortization:	(148.8)		(133.2)
Foreign currency translation adjustment:	(16.4)		(14.2)
Net carrying amounts	1,006.4		1,024.5
Customer relationships | Weighted average
Changes made to finite-lived intangible assets by reportable segment
Weighted average estimated useful life	16 years
Supply contracts
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	42.6		42.6
Accumulated amortization:	(4.5)		(4.1)
Net carrying amounts	38.1		38.5
Supply contracts | Weighted average
Changes made to finite-lived intangible assets by reportable segment
Weighted average estimated useful life	18 years
Technology
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	32.3		32.3
Accumulated amortization:	(14.5)		(14.0)
Net carrying amounts	17.8		18.3
Technology | Weighted average
Changes made to finite-lived intangible assets by reportable segment
Weighted average estimated useful life	16 years
Trade names
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	6.0		6.0
Accumulated amortization:	(0.8)		(0.7)
Net carrying amounts	5.2		5.3
Trade names | Weighted average
Changes made to finite-lived intangible assets by reportable segment
Weighted average estimated useful life	15 years
Chlorovinyls
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	1,205.8		1,205.8
Accumulated impairment charges	(2.9)		(2.6)
Accumulated amortization:	(143.1)		(127.2)
Foreign currency translation adjustment:	(16.4)		(14.2)
Net carrying amounts	1,043.4		1,061.8
Chlorovinyls | Customer relationships
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	1,142.3		1,142.3
Accumulated impairment charges	(2.9)		(2.6)
Accumulated amortization:	(136.3)		(121.1)
Foreign currency translation adjustment:	(16.4)		(14.2)
Net carrying amounts	986.7		1,004.4
Chlorovinyls | Supply contracts
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	42.6		42.6
Accumulated amortization:	(4.5)		(4.1)
Net carrying amounts	38.1		38.5
Chlorovinyls | Technology
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	14.9		14.9
Accumulated amortization:	(1.5)		(1.3)
Net carrying amounts	13.4		13.6
Chlorovinyls | Trade names
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	6.0		6.0
Accumulated amortization:	(0.8)		(0.7)
Net carrying amounts	5.2		5.3
Building Products
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	49.6		49.6
Accumulated amortization:	(25.5)		(24.8)
Net carrying amounts	24.1		24.8
Building Products | Customer relationships
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	32.2		32.2
Accumulated amortization:	(12.5)		(12.1)
Net carrying amounts	19.7		20.1
Building Products | Technology
Changes made to finite-lived intangible assets by reportable segment
Gross carrying amounts	17.4		17.4
Accumulated amortization:	(13.0)		(12.7)
Net carrying amounts	$ 4.4		$ 4.7