XML 80 R66.htm IDEA: XBRL DOCUMENT v3.19.1

Employee Benefits - Schedule of Fair Value of Total Assets By Category (Details) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	$ 81,241	$ 88,452	$ 79,087
Pension Plan
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	81,268	88,452
Pension Plan | Level 1
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	853	32,803
Pension Plan | Level 2
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	80,415	55,649
Pension Plan | Level 3
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Return-seeking securities - Corporate bonds
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	10,393
Pension Plan | Return-seeking securities - Corporate bonds | Level 1
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	10,393
Pension Plan | Return-seeking securities - Corporate bonds | Level 2
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Return-seeking securities - Corporate bonds | Level 3
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Global equity securities
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	25
Pension Plan | Global equity securities | Level 1
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	25
Pension Plan | Global equity securities | Level 2
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Global equity securities | Level 3
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Return-seeking securities - Collective investment trust
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	55,766	43,910
Pension Plan | Return-seeking securities - Collective investment trust | Level 1
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Return-seeking securities - Collective investment trust | Level 2
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	55,766	43,910
Pension Plan | Return-seeking securities - Collective investment trust | Level 3
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Liability-matching securities - Corporate bonds
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	20,711
Pension Plan | Liability-matching securities - Corporate bonds | Level 1
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	20,711
Pension Plan | Liability-matching securities - Corporate bonds | Level 2
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Liability-matching securities - Corporate bonds | Level 3
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Liability-matching securities - Collective investment trusts
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	24,649	11,739
Pension Plan | Liability-matching securities - Collective investment trusts | Level 1
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Liability-matching securities - Collective investment trusts | Level 2
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	24,649	11,739
Pension Plan | Liability-matching securities - Collective investment trusts | Level 3
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Cash and cash equivalents
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	853	1,674
Pension Plan | Cash and cash equivalents | Level 1
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	853	1,674
Pension Plan | Cash and cash equivalents | Level 2
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	0	0
Pension Plan | Cash and cash equivalents | Level 3
Asset allocation structure of the portfolio
Fair value of plan assets by asset category	$ 0	$ 0

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(01)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(01)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(ii)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(ii)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=bxc_ReturnSeekingSecuritiesCorporateBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=bxc_GlobalEquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=bxc_ReturnseekingSecuritiesCollectiveInvestmentTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=bxc_LiabilitymatchingSecuritiesCorporateBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=bxc_LiabilitymatchingSecuritiesCollectiveInvestmentTrustsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: