Average remaining life expectancy of inactive participants.

No definition available.

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- Definition

Expense for earn out liability.

+ References

No definition available.

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- Definition

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(3)

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- Definition

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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- Definition

Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)(4)

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- Definition

Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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-Publisher FASB

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-Section 50

-Paragraph 1

-Subparagraph (c)

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- Definition

Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

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- Definition

The amount of identifiable intangible assets recognized as of the acquisition date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

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- Definition

Amount of gain (loss) on sale or disposal of an equity method investment.

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No definition available.

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- Definition

Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, resulting from a business combination.

+ References

No definition available.

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- Definition

Amount of amortization expense expected to be recognized during the next fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

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- Definition

Amount of amortization expense expected to be recognized during the fifth fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of amortization expense expected to be recognized during the fourth fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of amortization expense expected to be recognized during the third fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of amortization expense expected to be recognized during the second fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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- Definition

Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill.

+ References

No definition available.

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ACCOUNTING POLICIES (Detail Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended			2 Months Ended	8 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2011	Aug. 31, 2007	Aug. 22, 2012
Accounting Policies [Abstract]
Expense for earnout liability		$ 7.9olin_ExpenseForEarnOutLiability	$ 11.5olin_ExpenseForEarnOutLiability
Gain (Loss) on Sale of Equity Investments	0	6.5	0
Asset retirement obligation non-current	44.2	47.3
Asset Retirement Obligation, Revision of Estimate	2.0	1.6
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expense	14.6us-gaap_AdjustmentForAmortization	14.6us-gaap_AdjustmentForAmortization	6.5us-gaap_AdjustmentForAmortization
Amortization expense expected in year one	14.6
Amortization expense expected in year two	14.6
Amortization expense expected in year three	14.5
Amortization expense expected in year four	14.5
Amortization expense expected in year five	14.5
Average remaining life expectancy of the inactive participants in the defined benefit pension plan (in years)	18	18.0
Goodwill
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill and Intangible Asset Impairment	0	0	0
Customers, customer contracts and relationships \| KA Steel
Acquired Finite-Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles						128.0
Amortization period (in years)	10 years 0 months 0 days
Customers, customer contracts and relationships \| SunBelt
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets				5.8
Amortization period (in years)	15 years 0 months 0 days
Customers, customer contracts and relationships \| Pioneer
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets					19.0
Amortization period (in years)	15 years 0 months 0 days
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill and Intangible Asset Impairment	0	0	0
Trademarks \| KA Steel
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)						10.9
Other Intangible Assets \| KA Steel
Acquired Finite-Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles						0.4
Amortization period (in years)	4 years 0 months 0 days
Other Intangible Assets \| Pioneer
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets					$ 1.2
Amortization period (in years)	5 years 0 months 0 days