SEGMENT INFORMATION (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 segment	Sep. 30, 2013
Segment information
Number of reportable segments			3
Segment information
Total net sales	$ 1,269.4	$ 1,197.5	$ 3,500.0	$ 3,531.5
Operating income (loss)	74.2	78.1	132.2	273.9
Interest expense, net	(19.5)	(19.7)	(56.9)	(57.4)
Loss on redemption and other debt costs				(78.5)
Gain on acquisition of controlling interest				23.5
Foreign exchange loss	(0.3)	(0.4)	(0.2)
Income before income taxes	54.4	58.0	75.1	161.5
Operating segments
Segment information
Total net sales	1,269.4	1,197.5	3,500.0	3,531.5
Chlorovinyls
Segment information
Total net sales	769.4	750.0	2,229.5	2,166.3
Operating income (loss)	69.6	101.6	159.5	311.0
Chlorovinyls | Operating segments
Segment information
Total net sales	844.8	811.8	2,424.6	2,351.1
Chlorovinyls | Intersegment elimination
Segment information
Total net sales	75.4	61.8	195.1	184.8
Building Products
Segment information
Number of primary product groups			2
Segment information
Total net sales	277.8	253.4	676.3	660.0
Operating income (loss)	24.0	(6.7)	27.4	(0.9)
Building Products | Operating segments
Segment information
Total net sales	277.8	253.4	676.3	660.0
Aromatics
Segment information
Total net sales	222.2	194.1	594.2	705.2
Operating income (loss)	2.0	5.2	(0.9)	22.5
Aromatics | Operating segments
Segment information
Total net sales	222.2	194.1	594.2	705.2
Eliminations, Unallocated and Other
Segment information
Operating income (loss)	(21.4)	(22.0)	(53.8)	(58.7)
Eliminations, Unallocated and Other | Operating segments
Segment information
Total net sales	(75.4)	(61.8)	(195.1)	(184.8)
Eliminations, Unallocated and Other | Intersegment elimination
Segment information
Total net sales	$ (75.4)	$ (61.8)	$ (195.1)	$ (184.8)