Debt Instrument, Percentage Of Principal, Discount

No definition available.

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Namespace Prefix:	bxc_
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Balance Type:	na
Period Type:	instant

- Definition

Amount of amortization expense attributable to debt issuance costs.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	instant

- 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

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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

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Balance Type:	credit
Period Type:	instant

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Balance Type:
Period Type:

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- Details

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- Details

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- Details

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Long-Term Debt - Narrative (Details) - USD ($)		9 Months Ended
Long-Term Debt - Narrative (Details) - USD ($)	Apr. 02, 2021	Oct. 01, 2022	Jan. 01, 2022	Oct. 31, 2021	Aug. 31, 2021
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 350,000,000
Outstanding principal balance		$ 0	$ 0
Line of credit facility, remaining borrowing capacity		$ 575,800,000	$ 431,700,000
Weighted average interest rate		0.00%	2.60%
Outstanding principal balance		$ 0	$ 0
Line of Credit \| Revolving Credit Facility \| Minimum \| LIBOR
Debt Instrument [Line Items]
Credit agreement interest rate		1.25%
Line of Credit \| Revolving Credit Facility \| Minimum \| Base Rate
Debt Instrument [Line Items]
Credit agreement interest rate		0.25%
Line of Credit \| Revolving Credit Facility \| Maximum \| LIBOR
Debt Instrument [Line Items]
Credit agreement interest rate		1.75%
Line of Credit \| Revolving Credit Facility \| Maximum \| Base Rate
Debt Instrument [Line Items]
Credit agreement interest rate		0.75%
6.0% Senior Secured Notes Due 2029 \| Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount				$ 300,000,000
Stated interest rate				6.00%
Percentage of principal, discount				98.625%
Term Loan Facility \| Secured Debt
Debt Instrument [Line Items]
Weighted average interest rate		0.00%	0.00%
Outstanding principal balance		$ 0	$ 0
Amortization of debt discount and issuance costs	$ 5,800,000