XML 68 R55.htm IDEA: XBRL DOCUMENT v3.8.0.1

Employee Benefits - Fair Value Of Plan Assets by Asset Category and Asset Categories As a Percentage of Total Assets (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by asset category	$ 88,452	$ 79,087	$ 78,264
Actual Allocation (as a percent)	100.00%	100.00%
Global equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by asset category		$ 48,134
Actual Allocation (as a percent)		61.00%
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by asset category		$ 30,493
Actual Allocation (as a percent)		38.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by asset category		$ 460
Actual Allocation (as a percent)		1.00%

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

Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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

X

- Definition

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2446-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

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

X

- Details

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

X

- Details

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