| 
           Postretirement Benefits Fair Values of Trust's Pension Assets (Details) (USD $) In Millions, unless otherwise specified 
         | 
        
           Dec. 31, 2014 
         | 
        
           Dec. 31, 2013 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
$ 965.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
 | 
        [1] | 
        
$ 956.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
 | 
        [2] | 
      
      
        | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
6.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1] | 
        
27.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2] | 
      
      
        | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
964.6us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1] | 
        
944.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2] | 
      
      
        | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [2] | 
      
      
        | Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
6.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2] | 
      
      
        | Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
145.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1] | 
        
237.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2] | 
      
      
        | Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [2] | 
      
      
        | United States Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1],[3] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2],[4] | 
      
      
        | United States Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
164.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1],[3] | 
        
243.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2],[4] | 
      
      
        | United States Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1],[3] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [2],[4] | 
      
      
        | International Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1],[3] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2],[4] | 
      
      
        | International Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
28.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1],[3] | 
        
46.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2],[4] | 
      
      
        | International Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1],[3] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [2],[4] | 
      
      
        | Government Fixed-Income Securities [Member] | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1],[5] | 
        
27.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2],[6] | 
      
      
        | Government Fixed-Income Securities [Member] | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
119.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1],[5] | 
        
42.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2],[6] | 
      
      
        | Government Fixed-Income Securities [Member] | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1],[5] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [2],[6] | 
      
      
        | Corporate Fixed-Income Securities [Member] | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1],[7] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2],[7] | 
      
      
        | Corporate Fixed-Income Securities [Member] | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
372.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1],[7] | 
        
157.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2],[7] | 
      
      
        | Corporate Fixed-Income Securities [Member] | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1],[7] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [2],[7] | 
      
      
        | Commingled Funds [Member] | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1],[8] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2],[8] | 
      
      
        | Commingled Funds [Member] | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
141.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1],[8] | 
        
208.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2],[8] | 
      
      
        | Commingled Funds [Member] | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1],[8] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [2],[8],[9] | 
      
      
        | Other Investment Companies [Member] | Fair Value, Inputs, Level 1 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_OtherInvestmentCompaniesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [1],[9] | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_OtherInvestmentCompaniesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
 | 
        [2],[9] | 
      
      
        | Other Investment Companies [Member] | Fair Value, Inputs, Level 2 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
(6.2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_OtherInvestmentCompaniesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [1],[9] | 
        
9.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_OtherInvestmentCompaniesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
 | 
        [2],[9] | 
      
      
        | Other Investment Companies [Member] | Fair Value, Inputs, Level 3 [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_OtherInvestmentCompaniesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
 | 
        [1],[9] | 
         
 | 
         | 
      
      
        | Estimate of Fair Value Measurement [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
970.9us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1] | 
        
971.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2] | 
      
      
        | Estimate of Fair Value Measurement [Member] | Short-term Investments [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
151.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1] | 
        
237.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2] | 
      
      
        | Estimate of Fair Value Measurement [Member] | United States Equity Securities [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
164.4us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1],[3] | 
        
243.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_UsEquitySecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2],[4] | 
      
      
        | Estimate of Fair Value Measurement [Member] | International Equity Securities [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
28.1us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1],[3] | 
        
46.8us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_InternationalEquitySecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2],[4] | 
      
      
        | Estimate of Fair Value Measurement [Member] | Government Fixed-Income Securities [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
119.7us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1],[5] | 
        
70.2us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2],[6] | 
      
      
        | Estimate of Fair Value Measurement [Member] | Corporate Fixed-Income Securities [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
372.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1],[7] | 
        
157.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2],[7] | 
      
      
        | Estimate of Fair Value Measurement [Member] | Commingled Funds [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
141.3us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1],[8] | 
        
208.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_CommingledFundsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2],[8] | 
      
      
        | Estimate of Fair Value Measurement [Member] | Other Investment Companies [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
(6.2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_OtherInvestmentCompaniesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [1],[9] | 
        
9.0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_OtherInvestmentCompaniesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [2],[9] | 
      
      
        | Estimate of Fair Value Measurement [Member] | Other Pension Plan Liabilities [Member] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Defined Benefit Plan Disclosure [Line Items] | 
         
 | 
         | 
         
 | 
         | 
      
      
        | Total pension plan net assets | 
        
$ (5.0)us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_OtherPensionPlanAssetsLiabilitiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [10] | 
        
$ (15.8)us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = bc_OtherPensionPlanAssetsLiabilitiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | 
        [10] | 
      
      
         | 
      
      
        | 
          
         |