XML 139 R82.htm IDEA: XBRL DOCUMENT v2.4.1.9
PENSION PLANS (Details 1) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Change in Benefit Obligation [Roll Forward]      
Benefit obligation at beginning of year $ 1,978.7us-gaap_DefinedBenefitPlanBenefitObligation $ 2,139.2us-gaap_DefinedBenefitPlanBenefitObligation  
Service cost 2.8us-gaap_DefinedBenefitPlanServiceCost 3.4us-gaap_DefinedBenefitPlanServiceCost  
Interest cost 86.5us-gaap_DefinedBenefitPlanInterestCost 81.1us-gaap_DefinedBenefitPlanInterestCost 92.0us-gaap_DefinedBenefitPlanInterestCost
Actuarial (gain) loss 255.6us-gaap_DefinedBenefitPlanActuarialGainLoss (109.4)us-gaap_DefinedBenefitPlanActuarialGainLoss  
Benefits paid (135.5)us-gaap_DefinedBenefitPlanBenefitsPaid (131.3)us-gaap_DefinedBenefitPlanBenefitsPaid  
Curtailments 0.2us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1 0us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1 0us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1
Currency translation adjustments (5.5)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation (4.3)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation  
Benefit obligation at end of year 2,182.8us-gaap_DefinedBenefitPlanBenefitObligation 1,978.7us-gaap_DefinedBenefitPlanBenefitObligation 2,139.2us-gaap_DefinedBenefitPlanBenefitObligation
Change in Plan Assets [Roll Forward]      
Fair value of plans' assets at beginning of year 1,860.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 1,981.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets  
Actual return on plans' assets 253.6us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets 11.0us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets  
Employer contributions 5.4us-gaap_DefinedBenefitPlanContributionsByEmployer 4.4us-gaap_DefinedBenefitPlanContributionsByEmployer  
Benefits paid (135.5)us-gaap_DefinedBenefitPlanBenefitsPaid (131.3)us-gaap_DefinedBenefitPlanBenefitsPaid  
Currency translation adjustments (5.5)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets (4.4)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets  
Fair value of plans' assets at end of year 1,978.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 1,860.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 1,981.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Funded Status [Abstract]      
Total funded status (204.1)us-gaap_DefinedBenefitPlanFundedStatusOfPlan (118.0)us-gaap_DefinedBenefitPlanFundedStatusOfPlan  
Qualified Pension Plan      
Funded Status [Abstract]      
Total funded status (138.7)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_QualifiedPensionPlanMember
(55.9)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_QualifiedPensionPlanMember
 
Non-Qualified Pension Plan      
Change in Benefit Obligation [Roll Forward]      
Benefit obligation at end of year 65.4us-gaap_DefinedBenefitPlanBenefitObligation
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember
62.1us-gaap_DefinedBenefitPlanBenefitObligation
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember
 
Funded Status [Abstract]      
Total funded status (65.4)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember
(62.1)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember
 
United States Pension Plans of US Entity, Defined Benefit      
Change in Benefit Obligation [Roll Forward]      
Benefit obligation at beginning of year 1,916.5us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
2,070.8us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Service cost 2.3us-gaap_DefinedBenefitPlanServiceCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
2.8us-gaap_DefinedBenefitPlanServiceCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Interest cost 83.8us-gaap_DefinedBenefitPlanInterestCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
78.4us-gaap_DefinedBenefitPlanInterestCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Actuarial (gain) loss 245.8us-gaap_DefinedBenefitPlanActuarialGainLoss
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
(107.7)us-gaap_DefinedBenefitPlanActuarialGainLoss
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Benefits paid (131.9)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
(127.8)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Curtailments 0us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
0us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Currency translation adjustments 0us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
0us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Benefit obligation at end of year 2,116.5us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
1,916.5us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Change in Plan Assets [Roll Forward]      
Fair value of plans' assets at beginning of year 1,798.6us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
1,912.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Actual return on plans' assets 244.2us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
10.7us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Employer contributions 4.5us-gaap_DefinedBenefitPlanContributionsByEmployer
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
3.2us-gaap_DefinedBenefitPlanContributionsByEmployer
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Benefits paid (131.9)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
(127.8)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Currency translation adjustments 0us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
0us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Fair value of plans' assets at end of year 1,915.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
1,798.6us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
Funded Status [Abstract]      
Total funded status (201.1)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
(117.9)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
 
United States Pension Plans of US Entity, Defined Benefit | Qualified Pension Plan      
Funded Status [Abstract]      
Total funded status (137.5)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_QualifiedPensionPlanMember
(57.6)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_QualifiedPensionPlanMember
 
United States Pension Plans of US Entity, Defined Benefit | Non-Qualified Pension Plan      
Funded Status [Abstract]      
Total funded status (63.6)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember
(60.3)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember
 
Foreign Pension Plans, Defined Benefit      
Change in Benefit Obligation [Roll Forward]      
Benefit obligation at beginning of year 62.2us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
68.4us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Service cost 0.5us-gaap_DefinedBenefitPlanServiceCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
0.6us-gaap_DefinedBenefitPlanServiceCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Interest cost 2.7us-gaap_DefinedBenefitPlanInterestCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
2.7us-gaap_DefinedBenefitPlanInterestCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Actuarial (gain) loss 9.8us-gaap_DefinedBenefitPlanActuarialGainLoss
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
(1.7)us-gaap_DefinedBenefitPlanActuarialGainLoss
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Benefits paid (3.6)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
(3.5)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Curtailments 0.2us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
0us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Currency translation adjustments (5.5)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
(4.3)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Benefit obligation at end of year 66.3us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
62.2us-gaap_DefinedBenefitPlanBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Change in Plan Assets [Roll Forward]      
Fair value of plans' assets at beginning of year 62.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
68.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Actual return on plans' assets 9.4us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
0.3us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Employer contributions 0.9us-gaap_DefinedBenefitPlanContributionsByEmployer
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
1.2us-gaap_DefinedBenefitPlanContributionsByEmployer
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Benefits paid (3.6)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
(3.5)us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Currency translation adjustments (5.5)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
(4.4)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Fair value of plans' assets at end of year 63.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
62.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Funded Status [Abstract]      
Total funded status (3.0)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
(0.1)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
 
Foreign Pension Plans, Defined Benefit | Qualified Pension Plan      
Funded Status [Abstract]      
Total funded status (1.2)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_QualifiedPensionPlanMember
1.7us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_QualifiedPensionPlanMember
 
Foreign Pension Plans, Defined Benefit | Non-Qualified Pension Plan      
Funded Status [Abstract]      
Total funded status $ (1.8)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember
$ (1.8)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
/ olin_FundedStatusDefinedBenefitPlanAxis
= olin_NonQualifiedPensionPlanMember