DESCRIPTION OF BUSINESS	3 Months Ended	12 Months Ended
DESCRIPTION OF BUSINESS	Mar. 31, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS	DESCRIPTION OF BUSINESS Olin Corporation (Olin) is a Virginia corporation, incorporated in 1892, having its principal executive offices in Clayton, MO. On October 5, 2015 (the Closing Date), we acquired from The Dow Chemical Company (TDCC) its U.S. Chlor Alkali and Vinyl, Global Chlorinated Organics and Global Epoxy businesses (collectively, the Acquired Business), whose operating results are included in the accompanying financial statements since the Closing Date. For segment reporting purposes, a portion of the Acquired Business’s operating results comprise the newly created Epoxy segment with the remaining operating results combined with Olin’s former Chlor Alkali Products and Chemical Distribution segments to comprise the newly created Chlor Alkali Products and Vinyls segment. We are a manufacturer concentrated in three business segments: Chlor Alkali Products and Vinyls, Epoxy and Winchester. Chlor Alkali Products and Vinyls manufactures and sells chlorine and caustic soda, ethylene dichloride and vinyl chloride monomer, methyl chloride, methylene chloride, chloroform, carbon tetrachloride, perchloroethylene, trichloroethylene and vinylidene chloride, hydrochloric acid, hydrogen, bleach products and potassium hydroxide. The Epoxy segment produces and sells a full range of epoxy materials, including allyl chloride, epichlorohydrin, liquid epoxy resins and downstream products such as converted epoxy resins and additives. The Winchester segment products include sporting ammunition, reloading components, small caliber military ammunition and components, and industrial cartridges. We have prepared the condensed financial statements included herein, without audit, pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (SEC). The preparation of the consolidated financial statements requires estimates and assumptions that affect amounts reported and disclosed in the financial statements and related notes. In our opinion, these financial statements reflect all adjustments (consisting only of normal accruals), which are necessary to present fairly the results for interim periods. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles have been condensed or omitted pursuant to such rules and regulations; however, we believe that the disclosures are appropriate. We recommend that you read these condensed financial statements in conjunction with the financial statements, accounting policies and the notes thereto and Management’s Discussion and Analysis of Financial Condition and Results of Operations included in our Annual Report on Form 10-K for the year ended December 31, 2015. Certain reclassifications were made to prior year amounts to conform to the 2016 presentation.	DESCRIPTION OF BUSINESS Olin Corporation is a Virginia corporation, incorporated in 1892, having its principal executive offices in Clayton, MO. On October 5, 2015 (the Closing Date), we acquired from The Dow Chemical Company (TDCC) its U.S. Chlor Alkali and Vinyl, Global Chlorinated Organics and Global Epoxy businesses (collectively, the Acquired Business), whose operating results are included in the accompanying financial statements since the Closing Date. For segment reporting purposes, a portion of the Acquired Business’s operating results comprise the newly created Epoxy segment with the remaining operating results combined with Olin’s Chlor Alkali Products and Chemical Distribution segments to comprise the newly created Chlor Alkali Products and Vinyls segment. We are a manufacturer concentrated in three business segments: Chlor Alkali Products and Vinyls, Epoxy and Winchester. Chlor Alkali Products and Vinyls manufactures and sells chlorine and caustic soda, ethylene dichloride and vinyl chloride monomer, methyl chloride, methylene chloride, chloroform, carbon tetrachloride, perchloroethylene, trichloroethylene and vinylidene chloride, hydrochloric acid, hydrogen, bleach products and potassium hydroxide. The Epoxy segment produces and sells a full range of epoxy materials, including allyl chloride, epichlorohydrin, liquid epoxy resins and downstream products such as converted epoxy resins and additives. The Winchester segment products include sporting ammunition, reloading components, small caliber military ammunition and components, and industrial cartridges. See our discussion of our segment disclosures contained in Item 7—“Management’s Discussion and Analysis of Financial Condition and Results of Operations” to Olin’s Annual Report on Form 10-K for the year ended December 31, 2015.