ACCOUNTS RECEIVABLE (Details Textuals) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2017	Dec. 31, 2016	Dec. 22, 2016
ACCOUNTS RECEIVABLE [Abstract]
Secured Borrowing Maximum Capacity		$ 250.0
Transfers Accounted for as Secured Borrowings, Assets, Carrying Amount	$ 316.5	282.3
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount	210.0	210.0
Secured Borrowing Available Capacity	34.1
Repayments of Secured Debt		210.0
Sumitomo Credit Facility		800.0
Transfer of Financial Assets, Facility Maximum			$ 271.5
Proceeds from Sale and Collection of Receivables	389.6
Continuing Involvement with Derecognized Transferred Financial Assets, Amount Outstanding	$ 145.0	$ 126.1

ACCOUNTS RECEIVABLE [Abstract]

No definition available.

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- Definition

Represents the amount of available borrowing capacity under the Receivables Financing Agreement as of the date of the statement of financial position.

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

Maximum capacity under secured borrowing facility to be recognized in the transferor's statement of financial position at the end of each period presented.

+ References

No definition available.

+ Details

Name:	olin_SecuredBorrowingMaximumCapacity
Namespace Prefix:	olin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Term credit facility with a syndicate of lenders and Sumitomo Mitsui Banking Corporation under which Olin obtained term loans that were borrowed upon on the Closing Date of the Transactions.

+ References

No definition available.

+ Details

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Balance Type:	credit
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- Definition

Repayments of debt outstanding under the Sumitomo Credit Facility.

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

Maximum amount of potential receivables which can be sold under the facility.

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

Amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction that have been derecognized. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=51814546&loc=d3e107314-111719

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash inflow associated with the proceeds from sale and collection of receivables during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585

+ Details

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Balance Type:	debit
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- Definition

Carrying amount of financial assets accounted for as secured borrowings recognized in the transferor's statement of financial position at the end of each period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=55761124&loc=SL6224234-111729

+ Details

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Balance Type:	debit
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- Definition

Carrying amount of liabilities associated with financial assets accounted for as secured borrowings recognized in the transferor's statement of financial position at the end of each period presented.

+ References

+ Details

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