SEGMENT INFORMATION (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Segment Reporting Information [Line Items]
Total sales	$ 550.2	$ 432.8	$ 1,515.3	$ 1,200.5
Income before taxes [Abstract]
Income before taxes	69.4	38.8	352.9	79.2
Total environmental expense	2.5	8.4	2.9	9.1
Restructuring charges	(4.1)	0	(6.6)	0
Other operating income	4.3	0.3	5.9	2.6
Interest expense	(7.9)	(6.4)	(22.5)	(19.5)
Interest income	0.2	0.3	0.7	0.7
Other (expense) income	(1.6)	0	179.0	0.1
Chlor Alkali Products [Member]
Segment Reporting Information [Line Items]
Total sales	386.1	275.3	1,065.8	763.9
Income before taxes [Abstract]
Income before taxes	76.7	44.0	194.7	80.7
Winchester [Member]
Segment Reporting Information [Line Items]
Total sales	164.1	157.5	449.5	436.6
Income before taxes [Abstract]
Income before taxes	13.1	18.8	37.4	59.4
Corporate/Other [Member]
Income before taxes [Abstract]
Total environmental expense	(2.5)	(8.4)	(2.9)	(9.1)
Pension income	6.9	7.0	20.8	18.2
Other corporate and unallocated costs	(15.7)	(16.8)	(53.6)	(53.9)
Restructuring charges	$ (4.1)	$ 0	$ (6.6)	$ 0