Estimated capital spending for facility relocation.

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Estimated project cost for plant relocation.

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Freeport product segment production capacity decrease announced on March 21, 2016

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Government grants for capital spending on a facility relocation.

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Henderson, NV chlor alkali product segment production capacity decrease announced on March 21, 2016

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Niagara Falls, NY chlor alkali product segment production capacity

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Tonnage capacity reduction in a product segment.

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Reduced Niagara Falls, NY chlor alkali product segment production capacity

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Total chlor alkali product segment production capacity decrease announced on March 21, 2016

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Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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Amount expected to be recognized in earnings for the specified restructuring cost.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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Amount of decrease in the reserve for full or partial settlement through consideration other than cash.

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RESTRUCTURING CHARGES (Details Textuals) $ in Millions	3 Months Ended						9 Months Ended		18 Months Ended	34 Months Ended	83 Months Ended
RESTRUCTURING CHARGES (Details Textuals) $ in Millions	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Mar. 21, 2016 T	Dec. 31, 2015 USD ($)	Dec. 12, 2014 T	Dec. 31, 2011 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 9.2	$ 8.5	$ 8.2	$ 5.2	$ 8.2	$ 92.8	$ 25.9	$ 106.2			$ 175.5
Inception to date Amounts Utilized (cash)											68.2
Inception to date Amounts Utilized (non-cash)											84.6
Accrued restructuring costs	21.9			11.9			21.9	11.9	$ 21.9	$ 21.9	21.9	$ 12.7		$ 6.7
Chlor Alkali Products and Vinyls Capacity Reductions
Restructuring Cost and Reserve [Line Items]
Total Product Segment Production Capacity Decrease \| T													433,000
Henderson Product Segment Production Capacity Decrease \| T													153,000
Niagara Product Segment Production Capacity \| T													300,000
Reduced Niagara Segment Production Capacity \| T													240,000
Freeport Product Segment Production Capacity Decrease \| T													220,000
Restructuring charges	8.8			4.9			23.7	105.0	135.0
Additional restructuring and related expected cost	25.0						25.0		25.0	25.0	25.0
Chlor Alkali Products Becancour
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.4			0.1			2.2	0.4		15.0
Additional restructuring and related expected cost	4.0						4.0		4.0	4.0	4.0
Tonnage reduction in chlor alkali manufacutring capactiy (in tons) \| T															185,000
Winchester Segment
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 0.3				$ 0.8			25.5
Estimated Project Cost For Plant Relocation	110.0						110.0		110.0	110.0	110.0
Estimated Capital Spending For Facility Relocation	$ 80.0						$ 80.0		$ 80.0	$ 80.0	$ 80.0
Government Grants for Facility Relocation Capital Spending																$ 31.0