XML 130 R82.htm IDEA: XBRL DOCUMENT v2.4.1.9
Retirement Plans and Post Retirement Benefits Funded Status, Assumptions Used in Benefit Obligations and Amounts Recognized in Balance Sheets (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 12 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]          
Defined Benefit Plan, Actual Plan Asset Allocation     100.00%lpx_DefinedBenefitPlanActualPlanAssetAllocation 100.00%lpx_DefinedBenefitPlanActualPlanAssetAllocation  
Defined Benefit Plan, Target Allocation Percentage     1    
Change in Benefit Obligation [Roll Forward]          
Benefit obligation, beginning of year balance $ 352.0us-gaap_DefinedBenefitPlanBenefitObligation   $ 322.1us-gaap_DefinedBenefitPlanBenefitObligation $ 352.0us-gaap_DefinedBenefitPlanBenefitObligation  
Service cost     3.5us-gaap_DefinedBenefitPlanServiceCost 3.4us-gaap_DefinedBenefitPlanServiceCost 3.7us-gaap_DefinedBenefitPlanServiceCost
Interest cost     14.1us-gaap_DefinedBenefitPlanInterestCost 12.7us-gaap_DefinedBenefitPlanInterestCost 14.6us-gaap_DefinedBenefitPlanInterestCost
Actuarial (gain)/loss     37.4us-gaap_DefinedBenefitPlanActuarialGainLoss (24.1)us-gaap_DefinedBenefitPlanActuarialGainLoss  
Defined Benefit Plan, Transfers 0lpx_DefinedBenefitPlanTransfers 0.3lpx_DefinedBenefitPlanTransfers 0lpx_DefinedBenefitPlanTransfers 0.3lpx_DefinedBenefitPlanTransfers  
Curtailments/settlements     9.4us-gaap_DefinedBenefitPlanCurtailments 0us-gaap_DefinedBenefitPlanCurtailments  
Foreign exchange rate changes     (5.3)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation (3.6)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation  
Benefits paid     (17.1)us-gaap_DefinedBenefitPlanBenefitsPaid (18.6)us-gaap_DefinedBenefitPlanBenefitsPaid  
Benefit obligation, end of year balance     364.1us-gaap_DefinedBenefitPlanBenefitObligation 322.1us-gaap_DefinedBenefitPlanBenefitObligation 352.0us-gaap_DefinedBenefitPlanBenefitObligation
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, beginning of year balance 259.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets   270.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 259.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets  
Actual return on plan assets     10.2us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets 28.3us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets  
Employer contribution     9.6us-gaap_DefinedBenefitPlanContributionsByEmployer 4.2us-gaap_DefinedBenefitPlanContributionsByEmployer  
Foreign exchange rate changes     (5.0)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets (3.2)us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets  
Benefits paid     (17.1)us-gaap_DefinedBenefitPlanBenefitsPaid (18.6)us-gaap_DefinedBenefitPlanBenefitsPaid  
Fair value of plan assets, end of year balance     268.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 270.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 259.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Funded status     (96.1)us-gaap_DefinedBenefitPlanFundedStatusOfPlan (51.8)us-gaap_DefinedBenefitPlanFundedStatusOfPlan  
Weighted average assumptions for obligations as of measurement date [Abstract]          
Discount rate     3.82%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate 4.58%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate  
Rate of compensation increase     0.57%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease 0.63%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease  
Amounts Recognized in Balance Sheet [Abstract]          
Noncurrent pension assets, included in “Other assets”     0.6us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent 0.6us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent  
Current pension liabilities, included in “Accounts payable and accrued liabilities”     (2.7)us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities (0.2)us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities  
Noncurrent pension liabilities, included in “Other long-term liabilities”     (93.8)us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent (52.2)us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent  
Total     (95.9)us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet (51.8)us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet  
Amounts recognized in other comprehensive income—pre-tax          
Net actuarial loss     149.6us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax 112.1us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax  
Prior service cost     9.5us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax 0.1us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax  
Total     159.1us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax 112.2us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax  
Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]          
Accumulated benefit obligations     348.0us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation 304.7us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation  
Fair value of plan assets     217.9us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets 256.7us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets  
Plans with Projected Benefit Obligations in Excess of Plan Assets [Abstract]          
Projected benefit obligations     350.7us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateBenefitObligation 309.0us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateBenefitObligation  
Fair value of plan assets     217.9us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets 256.7us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets  
Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]          
Net actuarial loss     7.1us-gaap_DefinedBenefitPlanFutureAmortizationOfGainLoss    
Prior service cost     0.5us-gaap_DefinedBenefitPlanFutureAmortizationOfPriorServiceCostCredit    
Total     7.6us-gaap_DefinedBenefitPlanAmountToBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossNextFiscalYear    
Supplemental employee retirement plans, defined benefit          
Change in Benefit Obligation [Roll Forward]          
Benefits paid         (10.4)us-gaap_DefinedBenefitPlanBenefitsPaid
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Change in Assets (Fair Value) [Roll Forward]          
Benefits paid         (10.4)us-gaap_DefinedBenefitPlanBenefitsPaid
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Equity Securities          
Defined Benefit Plan Disclosure [Line Items]          
Defined Benefit Plan, Target Plan Asset Allocations     47.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_EquitySecuritiesMember
   
Defined Benefit Plan, Actual Plan Asset Allocation     45.70%lpx_DefinedBenefitPlanActualPlanAssetAllocation
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= us-gaap_EquitySecuritiesMember
46.40%lpx_DefinedBenefitPlanActualPlanAssetAllocation
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= us-gaap_EquitySecuritiesMember
 
Multi-strategy Funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     26.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_HedgeFundsMultistrategyMember
[1] 25.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= us-gaap_HedgeFundsMultistrategyMember
[1]  
Domestic stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     84.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_EquityFundsDomesticStockFundsMember
[2] 83.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= lpx_EquityFundsDomesticStockFundsMember
[2]  
International stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     37.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_EquityFundsInternationalStockFundsMember
[2] 42.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= lpx_EquityFundsInternationalStockFundsMember
[2]  
Domestic bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     62.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDomesticEquitiesMember
[3] 54.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= lpx_FixedIncomeFundsDomesticEquitiesMember
[2]  
International bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     40.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsInternationalBondFundMemberMember
[3] 34.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= lpx_FixedIncomeFundsInternationalBondFundMemberMember
[3]  
Diversified real asset funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     13.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDiversifiedRealAssetsMember
[3] 11.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= lpx_FixedIncomeFundsDiversifiedRealAssetsMember
[3]  
Real Estate          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[4] 16.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= us-gaap_RealEstateFundsMember
[4]  
Cash and Cash Equivalents          
Defined Benefit Plan Disclosure [Line Items]          
Defined Benefit Plan, Target Plan Asset Allocations     18.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
   
Defined Benefit Plan, Actual Plan Asset Allocation     10.50%lpx_DefinedBenefitPlanActualPlanAssetAllocation
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
10.60%lpx_DefinedBenefitPlanActualPlanAssetAllocation
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
 
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, beginning of year balance     3.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
   
Fair value of plan assets, end of year balance     2.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
3.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= us-gaap_CashAndCashEquivalentsMember
 
Debt Securities          
Defined Benefit Plan Disclosure [Line Items]          
Defined Benefit Plan, Target Plan Asset Allocations     27.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_DebtSecuritiesMember
   
Defined Benefit Plan, Actual Plan Asset Allocation     43.80%lpx_DefinedBenefitPlanActualPlanAssetAllocation
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= us-gaap_DebtSecuritiesMember
36.80%lpx_DefinedBenefitPlanActualPlanAssetAllocation
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= us-gaap_DebtSecuritiesMember
 
Real Estate          
Defined Benefit Plan Disclosure [Line Items]          
Defined Benefit Plan, Target Plan Asset Allocations     8.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_RealEstateMember
   
Defined Benefit Plan, Actual Plan Asset Allocation     0.00%lpx_DefinedBenefitPlanActualPlanAssetAllocation
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_RealEstateMember
6.20%lpx_DefinedBenefitPlanActualPlanAssetAllocation
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_RealEstateMember
 
Significant Unobservable Inputs (Level 3)          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     26.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
41.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= us-gaap_FairValueInputsLevel3Member
64.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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= us-gaap_FairValueInputsLevel3Member
Significant Unobservable Inputs (Level 3) | Multi-strategy Funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     26.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[1] 25.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[1] 49.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Significant Unobservable Inputs (Level 3) | Domestic stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2]  
Significant Unobservable Inputs (Level 3) | International stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
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[2] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2]  
Significant Unobservable Inputs (Level 3) | Domestic bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2]  
Significant Unobservable Inputs (Level 3) | International bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2]  
Significant Unobservable Inputs (Level 3) | Diversified real asset funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[3] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[3]  
Significant Unobservable Inputs (Level 3) | Real Estate          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[4] 16.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[4] 15.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Significant Unobservable Inputs (Level 3) | Cash and Cash Equivalents          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Fair Value, Inputs, Level 1 [Member]          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     160.6us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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148.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Fair Value, Inputs, Level 1 [Member] | Multi-strategy Funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[1]  
Fair Value, Inputs, Level 1 [Member] | Domestic stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     71.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2] 68.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2]  
Fair Value, Inputs, Level 1 [Member] | International stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     12.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2] 14.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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[2]  
Fair Value, Inputs, Level 1 [Member] | Domestic bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     62.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[2] 54.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDomesticEquitiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[2]  
Fair Value, Inputs, Level 1 [Member] | International bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsInternationalBondFundMemberMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[2] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsInternationalBondFundMemberMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[2]  
Fair Value, Inputs, Level 1 [Member] | Diversified real asset funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     13.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDiversifiedRealAssetsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[3] 11.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDiversifiedRealAssetsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[3]  
Fair Value, Inputs, Level 1 [Member] | Real Estate          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_RealEstateFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[4] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_RealEstateFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
[4]  
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
 
Fair Value, Inputs, Level 2          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     81.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
79.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
 
Fair Value, Inputs, Level 2 | Multi-strategy Funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_HedgeFundsMultistrategyMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[1] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_HedgeFundsMultistrategyMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[1]  
Fair Value, Inputs, Level 2 | Domestic stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     13.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_EquityFundsDomesticStockFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2] 14.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_EquityFundsDomesticStockFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2]  
Fair Value, Inputs, Level 2 | International stock funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     25.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_EquityFundsInternationalStockFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2] 28.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_EquityFundsInternationalStockFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2]  
Fair Value, Inputs, Level 2 | Domestic bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDomesticEquitiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDomesticEquitiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2]  
Fair Value, Inputs, Level 2 | International bond funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     40.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsInternationalBondFundMemberMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2] 34.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsInternationalBondFundMemberMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[2]  
Fair Value, Inputs, Level 2 | Diversified real asset funds          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDiversifiedRealAssetsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[3] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= lpx_FixedIncomeFundsDiversifiedRealAssetsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[3]  
Fair Value, Inputs, Level 2 | Real Estate          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_RealEstateFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[4] 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_RealEstateFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
[4]  
Fair Value, Inputs, Level 2 | Cash and Cash Equivalents          
Change in Assets (Fair Value) [Roll Forward]          
Fair value of plan assets, end of year balance     $ 2.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
$ 3.5us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_CashAndCashEquivalentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
 
[1] The multi-strategy funds invest in various hedge funds that employ a fund of funds strategy.
[2] Equity investments include investments in funds that are primarily invested in large capitalization U.S. and international equity securities and a mutual fund.
[3] Fixed income investments include investments in funds that are primarily invested in a diversified portfolio of investment grade U.S. and international debt securities.
[4] Real estate investments are primarily invested in U.S. commercial real estate.