Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Commodity forward contracts with Citibank, a major counterparty.

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Commodity forward contracts with Wells Fargo, a major counterparty.

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Interest Rate on SunBelt Notes

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Notional amount of interest rate fair value hedge that is discontinued.

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Face amount of Series G SunBelt notes.

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Face amount of Series O SunBelt Notes.

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The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

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Net fair value of all derivative instruments designated as cash flow hedging instruments, which is ordinarily reflected within other comprehensive income.

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-Name Accounting Standards Codification

-Topic 815

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-Section 45

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Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge.

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-SubTopic 25

-Section 35

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Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective interest rate fair value hedge that is amortized upon discontinuation of the interest rate fair value hedge.

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The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

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DERIVATIVE FINANCIAL INSTRUMENTS (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jun. 30, 2012	Dec. 22, 1997	Oct. 31, 2011	Dec. 31, 2014
Cash flow hedges [Abstract]
Commodity forward contracts with Wells Fargo	$ 52.6
Commodity forward contracts with Citibank	34.1
Cash Flow Hedges Derivative Instruments at Fair Value, Net	7.6
Cash Flow Hedge Gain (Loss) to be Reclassified wihtin Twelve Months	3.5
Fair value hedges [Abstract]
Amount of terminated interest rate swaps			73.1
Gain on terminated interest rate swaps	0.7		2.2
Series O Face Amount				97.5olin_SeriesOFaceAmount
Series G Face Amount				97.5olin_SeriesGFaceAmount
Interest Rate on SunBelt Notes				7.23%olin_InterestRateonSunBeltNotes
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net	0	0
Variable Interest Rate Swaps $125M
Derivative [Line Items]
Notional amount	125.0
Amount of gain included in long-term debt	3.1				11.0
Fixed Interest Rate Swaps $125M
Derivative [Line Items]
Notional amount	125.0
Interest Rate Swaps Designated As Fair Value Hedges
Derivative [Line Items]
Notional amount	$ 0	$ 0				$ 0