Debt Instrument, Interest Rate Term

No definition available.

Name:	bcbp_DebtInstrumentInterestRateTerm
Namespace Prefix:	bcbp_
Data Type:	xbrli:durationItemType
Balance Type:	na
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

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

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+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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

- Definition

Amount that would be paid, determined under the conditions specified in the contract, if the holder of the share has the right to redeem the shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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

- Definition

Stated interest rate of the subordinated debt.

+ References

No definition available.

+ Details

Name:	us-gaap_SubordinatedBorrowingInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

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

- Details

Name:	us-gaap_SubordinatedBorrowingAxis=bcbp_FixedToFloatingRateSubordinatedDebenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubordinatedBorrowingAxis=bcbp_TrustPreferredJuniorSubordinatedDebentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubordinatedBorrowingAxis=bcbp_FixedToFloatingRateAndTrustPreferredJuniorSubordinatedDebenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subordinated Debt (Narrative) (Details) - USD ($) $ in Thousands		9 Months Ended
	Aug. 01, 2023	Sep. 30, 2023	Dec. 31, 2022	Jul. 30, 2018
Subordinated Borrowing [Line Items]
Face amount				$ 33,500
Fixed To Floating Rate Subordinated Debentures [Member]
Subordinated Borrowing [Line Items]
Notes term		10 years
Deferred finance costs		$ 0	$ 116
Fixed To Floating Rate Subordinated Debentures [Member] \| First Five Years [Member]
Subordinated Borrowing [Line Items]
Interest rate		5.625%
Interest rate term		5 years
Fixed To Floating Rate Subordinated Debentures [Member] \| After Five Years [Member]
Subordinated Borrowing [Line Items]
Variable interest rate spread	2.72%
Trust Preferred Junior Subordinated Debenture [Member]
Subordinated Borrowing [Line Items]
Variable interest rate spread		2.65%
Trust preferred securities		$ 4,100
Fixed To Floating Rate And Trust Preferred Junior Subordinated Debentures [Member]
Subordinated Borrowing [Line Items]
Variable interest rate spread		0.26161%