Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Pension Liability

No definition available.

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

- Definition

Contribution to an individual retirement account as a percentage of employee's eligible compensation.

+ References

No definition available.

+ Details

Name:	olin_ContributionToIndividualRetirementAccountPercentageOfEmployeesEligibleCompensation
Namespace Prefix:	olin_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The increase in the fair value of plan assets from contributions made by the employer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of net gain (loss) recognized in net periodic benefit cost due to settlements and curtailments. Curtailments result from an event that significantly reduces the expected years of future service of present employees or eliminates for a significant number of employees the accrual of defined benefits for some or all of their future services. Settlements result from an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include, but are not limited to, lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contracts to cover vested benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)(7)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_ForeignPensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=olin_DCPBusinessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

PENSION PLANS AND RETIREMENT BENEFITS (Details Textuals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Oct. 05, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined contribution pension plans expense	$ 6.0	$ 4.0	$ 20.8	$ 12.9
Curtailments/settlements				(0.2)
United States Pension Plan of US Entity
Defined Benefit Plan Disclosure [Line Items]
Curtailments/settlements			0.0	0.1
Employer's contribution to defined benefit pension			6.0
Foreign Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer's contribution to defined benefit pension			$ 1.1	$ 0.5
Minimum
Defined Benefit Plan Disclosure [Line Items]
Contribution to individual retirement account as a percentage of employees eligible compensation	5.00%		5.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Contribution to individual retirement account as a percentage of employees eligible compensation	10.00%		10.00%
DCP Business
Defined Benefit Plan Disclosure [Line Items]
Pension liabilities assumed					$ 442.3
DCP Business \| United States Pension Plan of US Entity
Defined Benefit Plan Disclosure [Line Items]
Pension liabilities assumed					281.7
DCP Business \| Foreign Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension liabilities assumed					$ 160.6