SEGMENT INFORMATION (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended		32 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013
Segment Reporting Information [Line Items]
Segment Reporting Information, Intersegment Revenue	$ (26.3)		$ 0		$ (43.6)	$ 0
Synergies Transferred Between Segments	3.3				6.2
Total sales	652.2		508.7		1,282.2	1,015.9
Income before taxes [Abstract]
Income before taxes	62.7		63.3		126.5	123.8
Environmental expense	(2.4)		(0.3)		(4.2)	(3.1)
Restructuring charges	(0.2)	(2.3)	(1.8)	(1.9)	(2.5)	(3.7)	(55.9)
Other operating income (expense)	1.5		(0.1)		1.7	0.4
Interest expense	(9.7)		(5.8)		(18.8)	(12.3)
Interest income	0.1		0.3		0.2	0.5
Other expense	(2.2)		(2.1)		(4.4)	(4.7)
Chlor Alkali Products [Member]
Segment Reporting Information [Line Items]
Total sales	367.0		363.2		715.9	722.9
Income before taxes [Abstract]
Income before taxes	50.2		75.0		108.7	149.4
Chemical Distribution [Member]
Segment Reporting Information [Line Items]
Total sales	113.4		0		223.8	0
Income before taxes [Abstract]
Income before taxes	2.2		0		6.3	0
Winchester [Member]
Segment Reporting Information [Line Items]
Total sales	198.1		145.5		386.1	293.0
Income before taxes [Abstract]
Income before taxes	37.1		11.9		68.4	22.7
Corporate/Other [Member]
Income before taxes [Abstract]
Pension income	6.4		7.0		12.7	13.3
Environmental expense	(2.4)		(0.3)		(4.2)	(3.1)
Other corporate and unallocated costs	(20.3)		(20.8)		(41.6)	(38.7)
Restructuring charges	$ (0.2)		$ (1.8)		$ (2.5)	$ (3.7)