Document And Entity Information - USD ($)
 9 Months Ended
Sep. 30, 2016
Jun. 30, 2015
Document and Entity Information [Abstract]    
Entity Registrant Name Olin Corporation  
Entity Central Index Key 0000074303  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Sep. 30, 2016  
Document Fiscal Year Focus 2016  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Entity Common Stock, Shares Outstanding 165,272,408  
Entity Well-known Seasoned Issuer Yes  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes  
Entity Public Float   $ 2,060,950,212