XML 147 R88.htm IDEA: XBRL DOCUMENT v2.4.1.9
Income Taxes (Narrative) (Details) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended 1 Months Ended 3 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Mar. 31, 2014
Dec. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Dec. 31, 2012
Income Taxes [Line Items]                    
Unrecognized Tax Benefits $ 142.6us-gaap_UnrecognizedTaxBenefits $ 145.2us-gaap_UnrecognizedTaxBenefits $ 138.4us-gaap_UnrecognizedTaxBenefits $ 127.2us-gaap_UnrecognizedTaxBenefits     142.6us-gaap_UnrecognizedTaxBenefits 145.2us-gaap_UnrecognizedTaxBenefits   138.4us-gaap_UnrecognizedTaxBenefits
Valuation allowances 87.9us-gaap_DeferredTaxAssetsValuationAllowance 109.3us-gaap_DeferredTaxAssetsValuationAllowance         87.9us-gaap_DeferredTaxAssetsValuationAllowance 109.3us-gaap_DeferredTaxAssetsValuationAllowance    
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued 1.5us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued           1.5us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued      
Deferred Tax Assets, Gross 331.8us-gaap_DeferredTaxAssetsGross 419.1us-gaap_DeferredTaxAssetsGross         331.8us-gaap_DeferredTaxAssetsGross 419.1us-gaap_DeferredTaxAssetsGross    
Deferred Tax Assets, Valuation Allowance 87.9us-gaap_DeferredTaxAssetsValuationAllowance 109.3us-gaap_DeferredTaxAssetsValuationAllowance         87.9us-gaap_DeferredTaxAssetsValuationAllowance 109.3us-gaap_DeferredTaxAssetsValuationAllowance    
Foreign tax credit carryforward gross 54.3awi_DeferredTaxAssetsTaxCreditCarryforwardsForeignGross                  
Foreign tax credit carryforward 12.1us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign 94.4us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign         12.1us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign 94.4us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign    
Estimated future taxable income to realize foreign tax credits 155.2awi_EstimatedFutureTaxableIncomeToRealizeForeignTaxCredits                  
Valuation allowance, decrease 21.4awi_ValuationAllowanceIncreaseDecrease                  
Dividend on foreign earnings       169.6awi_DividendOnForeignEarnings 169.6awi_DividendOnForeignEarnings          
Unremitted earnings not taxed 319.8awi_UnremittedEarningsInForeignInvestment                  
Unrecognized tax benefits 142.6us-gaap_UnrecognizedTaxBenefits 145.2us-gaap_UnrecognizedTaxBenefits 138.4us-gaap_UnrecognizedTaxBenefits 127.2us-gaap_UnrecognizedTaxBenefits     142.6us-gaap_UnrecognizedTaxBenefits 145.2us-gaap_UnrecognizedTaxBenefits   138.4us-gaap_UnrecognizedTaxBenefits
UTB if recognized would impact the reported effective tax rate 101.9us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate           101.9us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate      
UTB if recognized would impact the reported effective tax rate, net of federal benefit 99.5awi_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRateNetOfFederalBenefit           99.5awi_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRateNetOfFederalBenefit      
UTB increase (decrease) due to uncertain tax positions 10.5us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease 8.5us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease 10.2us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease              
Interest and penalty exposure reported as accrued income tax 1.5us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued           1.5us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued      
Deferred tax asset, net 243.9us-gaap_DeferredTaxAssetsNet 309.8us-gaap_DeferredTaxAssetsNet         243.9us-gaap_DeferredTaxAssetsNet 309.8us-gaap_DeferredTaxAssetsNet    
Federal [Member]                    
Income Taxes [Line Items]                    
Valuation allowances 31.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
          31.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
     
Deferred Tax Assets, Valuation Allowance 31.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
          31.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
     
Valuation allowance, decrease 6.3awi_ValuationAllowanceIncreaseDecrease
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
                 
UTB increase (decrease) due to uncertain tax positions 6.3us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
                 
State [Member]                    
Income Taxes [Line Items]                    
Operating loss carryforwards 969.6us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
1,067.3us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
        969.6us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
1,067.3us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
   
Valuation allowances 14.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
          14.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
     
Deferred Tax Assets, Valuation Allowance 14.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
          14.6us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
     
Estimated future taxable income to utilize deferred tax assets 1,012.8awi_EstimatedFutureTaxableIncomeToUtilizeDeferredTaxAsset
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
                 
Valuation allowance, decrease 5.2awi_ValuationAllowanceIncreaseDecrease
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
                 
UTB increase (decrease) due to uncertain tax positions (0.6)us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
                 
Foreign [Member]                    
Income Taxes [Line Items]                    
Operating loss carryforwards 158.3us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
252.8us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
        158.3us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
252.8us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
   
Operating loss carryforwards, finite 99.9awi_OperatingLossCarryforwardsFinite
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
          99.9awi_OperatingLossCarryforwardsFinite
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
     
Operating loss carryforwards, indefinite 58.4awi_OperatingLossCarryforwardsIndefinite
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
          58.4awi_OperatingLossCarryforwardsIndefinite
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
     
Valuation allowances 41.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  15.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
15.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
    41.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
    15.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Deferred Tax Assets, Valuation Allowance 41.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  15.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
15.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
    41.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
    15.7us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Foreign tax credit carryforward       21.1us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
           
Estimated future taxable income to realize foreign tax credits 51.7awi_EstimatedFutureTaxableIncomeToRealizeForeignTaxCredits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
                 
Valuation allowance, decrease 32.9awi_ValuationAllowanceIncreaseDecrease
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
                 
Deferred tax asset, net       5.4us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
           
Minimum [Member]                    
Income Taxes [Line Items]                    
Estimated reduction of net earnings 4.0awi_EstimatedReductionOfNetEarnings
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
                 
Minimum [Member] | State [Member]                    
Income Taxes [Line Items]                    
Operating loss carryforwards, expiration date 2015                  
Minimum [Member] | Foreign [Member]                    
Income Taxes [Line Items]                    
Operating loss carryforwards, expiration date 2015                  
Tax credit carryforward, expiration year 2015                  
Maximum [Member]                    
Income Taxes [Line Items]                    
Estimated reduction of net earnings $ 8.0awi_EstimatedReductionOfNetEarnings
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
                 
Maximum [Member] | State [Member]                    
Income Taxes [Line Items]                    
Operating loss carryforwards, expiration date 2034                  
Maximum [Member] | Foreign [Member]                    
Income Taxes [Line Items]                    
Operating loss carryforwards, expiration date 2032                  
Tax credit carryforward, expiration year 2022                  
Asbestos PI Trust And TPG [Member]                    
Income Taxes [Line Items]                    
Sale of stock by investee           3,900,000awi_SaleOfStockNumberOfSharesSoldByTwoMajorityShareholders
/ invest_InvestmentIssuerAxis
= awi_AsbestosPITrustAndArmorTPGHoldingsLLCMember
3,900,000awi_SaleOfStockNumberOfSharesSoldByTwoMajorityShareholders
/ invest_InvestmentIssuerAxis
= awi_AsbestosPITrustAndArmorTPGHoldingsLLCMember
6,000,000awi_SaleOfStockNumberOfSharesSoldByTwoMajorityShareholders
/ invest_InvestmentIssuerAxis
= awi_AsbestosPITrustAndArmorTPGHoldingsLLCMember
12,057,382awi_SaleOfStockNumberOfSharesSoldByTwoMajorityShareholders
/ invest_InvestmentIssuerAxis
= awi_AsbestosPITrustAndArmorTPGHoldingsLLCMember
5,980,000awi_SaleOfStockNumberOfSharesSoldByTwoMajorityShareholders
/ invest_InvestmentIssuerAxis
= awi_AsbestosPITrustAndArmorTPGHoldingsLLCMember