SEGMENT INFORMATION (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended			26 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Sales [Abstract]
Segment Reporting Information, Intersegment Revenue									$ 18.1
Sales	587.6	581.2	508.7	507.2	445.8	550.2	529.1	436.0	2,184.7	1,961.1	1,585.9
Income before taxes [Abstract]
Income before taxes by segment									225.2	379.4	76.9
Restructuring charge									(8.5)	(10.7)	(34.2)	(53.4)
Acquisition costs									(8.3)	(0.8)	0
Other operating income									7.6	8.8	2.5
Interest expense									(26.4)	(30.4)	(25.4)
Interest income									1.0	1.2	1.0
Other (expense) income									(11.3)	175.1	1.5
Earnings of non-consolidated affiliates [Abstract]
Total earnings of non-consolidated affiliates									3.0	9.6	29.9
Depreciation and amortization expense [Abstract]
Total depreciation and amortization expense									110.9	99.3	86.9
Capital spending [Abstract]
Total capital spending									255.7	200.9	85.3
Assets [Abstract]
Total assets	2,777.7				2,449.6				2,777.7	2,449.6		2,777.7
Investments-Affiliated Companies (at equity) [Abstract]
Investments in non-consolidated affiliates	29.3				27.6				29.3	27.6		29.3
Chlor Alkali Products Segment [Member]
Sales [Abstract]
Sales									1,410.8	1,389.1	1,036.6
Income before taxes [Abstract]
Income before taxes by segment									263.2	245.0	117.2
Restructuring charge									(2.3)	(2.8)	(28.0)	(33.1)
Earnings of non-consolidated affiliates [Abstract]
Total earnings of non-consolidated affiliates									3.0	9.6	29.9
Depreciation and amortization expense [Abstract]
Total depreciation and amortization expense									88.9	85.6	74.8
Capital spending [Abstract]
Total capital spending									221.3	134.2	67.6
Assets [Abstract]
Total assets	1,781.8				1,652.3				1,781.8	1,652.3		1,781.8
Investments-Affiliated Companies (at equity) [Abstract]
Investments in non-consolidated affiliates	29.3				27.6				29.3	27.6		29.3
Chemical Distribution [Member]
Sales [Abstract]
Sales									156.3	0	0
Income before taxes [Abstract]
Income before taxes by segment									4.5	0	0
Depreciation and amortization expense [Abstract]
Total depreciation and amortization expense									5.5	0	0
Capital spending [Abstract]
Total capital spending									0.8	0	0
Assets [Abstract]
Total assets	379.7				0				379.7	0		379.7
Winchester Segment [Member]
Sales [Abstract]
Sales									617.6	572.0	549.3
Income before taxes [Abstract]
Income before taxes by segment									55.2	37.9	63.0
Restructuring charge									(6.2)	(7.0)	(6.2)	(20.3)
Depreciation and amortization expense [Abstract]
Total depreciation and amortization expense									13.6	10.9	10.1
Capital spending [Abstract]
Total capital spending									32.1	63.9	15.2
Assets [Abstract]
Total assets	340.7				328.6				340.7	328.6		340.7
Corporate/Other [Member]
Income before taxes [Abstract]
Income before taxes by segment									(51.8)	(46.7)	(48.7)
Depreciation and amortization expense [Abstract]
Total depreciation and amortization expense									2.9	2.8	2.0
Capital spending [Abstract]
Total capital spending									1.5	2.8	2.5
Assets [Abstract]
Total assets	$ 275.5				$ 468.7				$ 275.5	$ 468.7		$ 275.5