Document And Entity Information (USD $)	9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012
Entity Registrant Name	Olin Corporation
Entity Central Index Key	0000074303
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$ 1,658,588,540
Entity Common Stock, Shares Outstanding	80,150,713
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2012