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Employee Benefits Employee Benefits (Details 6) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Jan. 03, 2015
Jan. 04, 2014
Dec. 29, 2012
Multiemployer Plans [Line Items]      
Multiemployer contributions for the period $ 1.0us-gaap_MultiemployerPlanPeriodContributions $ 1.3us-gaap_MultiemployerPlanPeriodContributions $ 1.3us-gaap_MultiemployerPlanPeriodContributions
Lumber Employees Local 786 Retirement Fund      
Multiemployer Plans [Line Items]      
Multiemployer Plans, Certified Zone Status Yellow    
Entity Tax Identification Number 516067407    
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan Implemented    
Multiemployer contributions for the period 0.4us-gaap_MultiemployerPlanPeriodContributions
/ us-gaap_MultiemployerPlanNameAxis
= bxc_LumberEmployeesLocal786RetirementFundMember
0.4us-gaap_MultiemployerPlanPeriodContributions
/ us-gaap_MultiemployerPlanNameAxis
= bxc_LumberEmployeesLocal786RetirementFundMember
0.4us-gaap_MultiemployerPlanPeriodContributions
/ us-gaap_MultiemployerPlanNameAxis
= bxc_LumberEmployeesLocal786RetirementFundMember
Multiemployer Plans, Certified Zone Status, Date Dec. 31, 2014    
Other Multiemployer Plans      
Multiemployer Plans [Line Items]      
Multiemployer contributions for the period $ 0.6us-gaap_MultiemployerPlanPeriodContributions
/ us-gaap_MultiemployerPlanNameAxis
= bxc_OtherMultiemployerPlansMember
$ 0.9us-gaap_MultiemployerPlanPeriodContributions
/ us-gaap_MultiemployerPlanNameAxis
= bxc_OtherMultiemployerPlansMember
$ 0.9us-gaap_MultiemployerPlanPeriodContributions
/ us-gaap_MultiemployerPlanNameAxis
= bxc_OtherMultiemployerPlansMember