RESTRUCTURING CHARGE (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended		44 Months Ended			3 Months Ended		6 Months Ended		44 Months Ended		3 Months Ended		6 Months Ended		44 Months Ended		6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014 Chlor Alkali Products Segment	Jun. 30, 2013 Chlor Alkali Products Segment	Jun. 30, 2014 Chlor Alkali Products Segment	Jun. 30, 2013 Chlor Alkali Products Segment	Jun. 30, 2014 Chlor Alkali Products Segment	Dec. 09, 2010 Chlor Alkali Products Segment T	Jun. 30, 2014 Winchester Segment	Jun. 30, 2013 Winchester Segment	Jun. 30, 2014 Winchester Segment	Jun. 30, 2013 Winchester Segment	Jun. 30, 2014 Winchester Segment	Dec. 31, 2011 Winchester Segment	Jun. 30, 2014 Winchester Segment Minimum	Jun. 30, 2014 Winchester Segment Maximum
Restructuring Cost and Reserve [Line Items]
Previous mercury cell capacity tonnage at Charleston, TN facility (in tons)															260,000
Membrane capacity tonnage capability at Charleston, TN facility (in tons)															200,000
Percentage reduction of electricity usage per ECU produced (in hundredths)										25.00%		25.00%		25.00%
Product Segment Production Capacity Decrease															160,000
Restructuring charges (credits)	$ 2.3	$ 1.0	$ 0.2	$ 2.3	$ 3.3	$ 2.5	$ 62.2			$ 1.7	$ (0.1)	$ 2.3	$ 1.4	$ 39.1		$ 0.6	$ 0.3	$ 1.0	$ 1.1	$ 23.1
Restructuring And Related Cost Expected Cost												1						4
Forecast annual reduction of Winchester's annual operating costs																						35	40
Estimated five-year project cost for Winchester relocation																110		110		110
Estimated capital spending for Winchester relocation																80		80		80
Government Grants for Facility Relocation Capital Spending																					31
Inception to date Amounts Utilized (cash)							23.2
Inception to date Amounts Utilized (non-cash)							28.6
Accrued restructuring costs	$ 10.4		$ 12.0		$ 10.4	$ 12.0	$ 10.4	$ 10.2	$ 13.9