SEGMENT INFORMATION (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended						9 Months Ended		23 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012
Segment Reporting Information [Line Items]
Segment Reporting Information, Intersegment Revenue	$ 4.8						$ 4.8
Total sales	581.2			550.2			1,597.1	1,515.3
Income before taxes [Abstract]
Income before taxes	46.7			69.4			170.5	352.9
Environmental expense	3.6			2.5			6.7	2.9
Restructuring charges	(2.3)	(1.8)	(1.9)	(4.1)	(2.4)	(0.1)	(6.0)	(6.6)	(50.9)
Acquisition costs	8.3			0			8.3	0.8
Other operating income	1.1			4.3			1.5	5.9
Interest expense	(6.0)			(7.9)			(18.3)	(22.5)
Interest income	0.2			0.2			0.7	0.7
Other (expense) income	(2.2)			(1.6)			(6.9)	179.0
Chlor Alkali Products [Member]
Segment Reporting Information [Line Items]
Total sales	364.8			386.1			1,087.7	1,065.8
Income before taxes [Abstract]
Income before taxes	59.5			76.7			208.9	194.7
Chemical Distribution [Member]
Segment Reporting Information [Line Items]
Total sales	47.6			0			47.6	0
Income before taxes [Abstract]
Income before taxes	1.9			0			1.9	0
Winchester [Member]
Segment Reporting Information [Line Items]
Total sales	168.8			164.1			461.8	449.5
Income before taxes [Abstract]
Income before taxes	16.0			13.1			38.7	37.4
Corporate/Other [Member]
Income before taxes [Abstract]
Pension income	7.2			6.9			20.5	20.8
Environmental expense	(3.6)			(2.5)			(6.7)	(2.9)
Other corporate and unallocated costs	(16.8)			(15.7)			(55.5)	(52.8)
Restructuring charges	(2.3)			(4.1)			(6.0)	(6.6)
Acquisition costs	$ (8.3)			$ 0			$ (8.3)	$ (0.8)