Line of credit accordion credit facility.

No definition available.

Name:	bxc_LineOfCreditAccordionCreditFacility
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line of Credit Facility, Alternative Base Amount Applied Against Minimum Percentage to Determine Required Excess Availability, Before Covered Ratio is Applicable

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityAlternativeBaseAmountAppliedAgainstMinimumPercentagetoDetermineRequiredExcessAvailabilityBeforeCoveredRatioisApplicable
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of Credit Facility, Alternative Base Amount Applied Against Minimum Percentage to Determine Required Excess Availability, Before Covered Ratio is Applicable While Concurrent Debt is Outstanding

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityAlternativeBaseAmountAppliedAgainstMinimumPercentagetoDetermineRequiredExcessFundsBeforeCoveredRatioisApplicableWhileConcurrentDebtisOutstanding
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of Credit Facility, Covenant Restriction, Coverage Ratio, Fixed Amount

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityCovenantRestrictionCoverageRatioFixedAmount
Namespace Prefix:	bxc_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Decrease to Borrowing Capacity, Under Amended Credit Agreement, Amount Per Month

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityDecreasetoBorrowingCapacityUnderAmendedCreditAgreementAmountPerMonth
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line of Credit Facility, Decrease to Borrowing Capacity, Unused Borrowing Capacity Threshold to Terminate Contractual Capacity Decrease, Under Amended Credit Agreement

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityDecreasetoBorrowingCapacityUnusedBorrowingCapacityThresholdtoTerminateContractualCapacityDecreaseUnderAmendedCreditAgreement
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Minimum Percentage of Maximum Borrowing Capacity or Alternative Base, Before Covered Ratio is Applicable

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityMinimumPercentageofMaximumBorrowingCapacityorAlternativeBaseBeforeCoveredRatioisApplicable
Namespace Prefix:	bxc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility, Minimum Remaining Borrowing Capacity Level Before Covered Ratio is Applicable

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityMinimumRemainingBorrowingCapacityLevelBeforeCoveredRatioisApplicable
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of Credit Facility, Minimum Remaining Borrowing Capacity Level Before Covered Ratio is Applicable While Concurrent Debt is Outstanding

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityMinimumRemainingBorrowingCapacityLevelBeforeCoveredRatioisApplicableWhileConcurrentDebtisOutstanding
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of Credit Facility, Revolving Credit Converted to Term Loan, Pursuant to Credit Agreement

+ References

No definition available.

+ Details

Name:	bxc_LineofCreditFacilityRevolvingCreditConvertedtoTermLoanPursuanttoCreditAgreement
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents amount of revolving credit facility excess availability threshold.

+ References

No definition available.

+ Details

Name:	bxc_RevolvingCreditFacilityExcessAvailabilityThresholdAmount
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

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

- Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=country_CA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Revolving Credit Facilities (Detail Textuals) (USD $)	12 Months Ended	0 Months Ended
Revolving Credit Facilities (Detail Textuals) (USD $)	Jan. 03, 2015	Aug. 14, 2014	Aug. 04, 2006
Revolving credit facility \| US
Line of Credit Facility [Line Items]
Fixed charge coverage ratio	1.1
Minimum remaining borrowing capacity level before covered ratio is applicable, while Tranche A Loan is outstanding	$ 33,200,000.0
Minimum remaining borrowing capacity level before covered ratio is applicable	31,800,000.0
Minimum percentage of maximum borrowing capacity or alternative base, before covered ratio is applicable	12.50%
Alternative base amount applied against minimum percentage to determine required excess funds, before covered ratio is applicable, while Tranche A Loan is outstanding	467,500,000.0
Alternative base amount applied against minimum percentage to determine required excess funds, before covered ratio is applicable	447,500,000.0
U.S. \| Revolving credit facility \| Wells Fargo Bank
Line of Credit Facility [Line Items]
Date of the final maturity of revolving credit facility			Apr. 15, 2016
U.S. revolving credit facility maximum available credit less the uncommitted accordion feature			467,500,000
Line of credit accordion credit			75,000,000
Revolving credit facility maximum available credit			542,500,000.0
Decrease to borrowing capacity of revolving credit facility per month		2,000,000
Outstanding lines of credit	225,600,000
Revolving credit facility excess availability	58,500,000
Interest rate on revolving credit facility	3.90%
U.S. \| Revolving credit facility \| Wells Fargo Bank \| Minimum
Line of Credit Facility [Line Items]
Unused borrowing capacity threshold of revolving credit facility to terminate contractual monthly capacity decrease		50,000,000
U.S. \| Tranche A Loan \| Wells Fargo Bank
Line of Credit Facility [Line Items]
Line of Credit Facility, Revolving Credit Converted to Term Loan, Pursuant to Credit Agreement			20,000,000.0
CANADA \| Revolving credit facility \| CIBC Asset Based Lending Inc \| Bluelinx Building Products Canada Ltd
Line of Credit Facility [Line Items]
Line of credit accordion credit	5,000,000.0
Revolving credit facility maximum available credit	15,000,000.0
Outstanding lines of credit	4,000,000
Revolving credit facility excess availability	1,000,000
Interest rate on revolving credit facility	4.00%
Maximum available credit	$ 10,000,000.0