RESTRUCTURING CHARGES (Detail Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended			50 Months Ended	1 Months Ended	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2011	Dec. 12, 2014 T	Dec. 09, 2010 T
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 15.7	$ 5.5	$ 8.5	$ 74.6
Restructuring and Related Cost, Incurred Cost				27.1
Restructuring Reserve, Settled without Cash				31.8
Accrued Restructuring Costs	15.7	10.2	13.9	15.7	15.7	15.7	12.1
Chlor Alkali Products Becancour
Restructuring Cost and Reserve [Line Items]
Tonnage reduction in chlor alkali manufacturing capacity (in tons)								185,000
Restructuring charges					10.0	10.0
Additional restructuring and related expected cost	5
Chlor Alkali Products Mercury
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3.8	3.7	2.3	40.6
Previous mercury cell capacity tonnage at Charleston, TN facility (in tons)									260,000
Membrane capacity tonnage capacity at Charleston, TN facility (in tons)									200,000
Winchester Segment
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.9	1.8	6.2	24.0
Additional restructuring and related expected cost	3
Estimated Project Cost For Plant Relocation	110			110	110	110
Estimated Capital Spending For Facility Relocation	80			80	80	80
Government Grants for Facility Relocation Capital Spending							31
Winchester Segment | Minimum
Restructuring Cost and Reserve [Line Items]
Forecast to reduce Winchester's annual operating costs	35
Winchester Segment | Maximum
Restructuring Cost and Reserve [Line Items]
Forecast to reduce Winchester's annual operating costs	$ 40