RESTRUCTURING CHARGE (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		29 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2.3	$ 1.9	$ 55.7
Write-off of equipment and facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			17.5
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.6	0.9	17.1
Facility Exit Costs (asset retirement obligations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.6	0.2	11.4
Pension and other postretirement benefits curtailment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			4.1
Employee Relocation Cost [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.1	0.8	4.5
Lease and Other Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0	1.1
Winchester Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.8	1.6	21.1
Winchester Segment [Member] | Write-off of equipment and facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0
Winchester Segment [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			11.5
Winchester Segment [Member] | Facility Exit Costs (asset retirement obligations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			1.1
Winchester Segment [Member] | Pension and other postretirement benefits curtailment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			4.1
Winchester Segment [Member] | Employee Relocation Cost [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			4.4
Winchester Segment [Member] | Lease and Other Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0
Chlor Alkali Products Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.5	0.3	34.6
Chlor Alkali Products Segment [Member] | Write-off of equipment and facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			17.5
Chlor Alkali Products Segment [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			5.6
Chlor Alkali Products Segment [Member] | Facility Exit Costs (asset retirement obligations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			10.3
Chlor Alkali Products Segment [Member] | Pension and other postretirement benefits curtailment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0
Chlor Alkali Products Segment [Member] | Employee Relocation Cost [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0.1
Chlor Alkali Products Segment [Member] | Lease and Other Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 1.1