SEGMENT INFORMATION (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Sales by Product Line
Total net sales	$ 1,134.5	$ 1,197.5	$ 1,272.8	$ 1,061.2	$ 784.7	$ 813.5	$ 867.7	$ 859.9	$ 4,666.0	$ 3,325.8	$ 3,222.9
Chlorovinyls
Sales by Product Line
Total net sales									2,917.3	1,344.9	1,318.7
Chlorovinyls | Chlor-alkali and derivative products
Sales by Product Line
Total net sales									2,447.2	886.2	888.3
Chlorovinyls | Compound products
Sales by Product Line
Total net sales									470.1	458.7	430.4
Building Products
Sales by Product Line
Total net sales									849.9	876.6	883.9
Building Products | Window and door profiles and moulding products
Sales by Product Line
Total net sales									314.4	319.1	331.0
Building Products | Outdoor building products
Sales by Product Line
Total net sales									535.5	557.5	552.9
Aromatics
Sales by Product Line
Total net sales									898.8	1,104.3	1,020.3
Aromatics | Cumene products
Sales by Product Line
Total net sales									569.8	763.5	603.8
Aromatics | Phenol and acetone products
Sales by Product Line
Total net sales									$ 329.0	$ 340.8	$ 416.5