Normal Retirement Age

No definition available.

Name:	bcbp_NormalRetirementAge
Namespace Prefix:	bcbp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Other Real Estate Owned, Number Of Properties

+ References

No definition available.

+ Details

Name:	bcbp_OtherRealEstateOwnedNumberOfProperties
Namespace Prefix:	bcbp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Postretirement Plan, Monthly Benefit Amount

+ References

No definition available.

+ Details

Name:	bcbp_PostretirementPlanMonthlyBenefitAmount
Namespace Prefix:	bcbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Significant Accounting Policies Disclosure [Line Items]

+ References

No definition available.

+ Details

Name:	bcbp_SignificantAccountingPoliciesDisclosureLineItems
Namespace Prefix:	bcbp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

+ Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123351718&loc=d3e2420-110228

+ Details

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Tax year being audited in the income tax examination, in YYYY format.

+ References

No definition available.

+ Details

Name:	us-gaap_IncomeTaxExaminationYearUnderExamination
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:gYearListItemType
Balance Type:	na
Period Type:	duration

- Definition

Tax year that remains open to examination under enacted tax laws, in YYYY format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32718-109319

+ Details

Name:	us-gaap_OpenTaxYear
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:gYearListItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Amount of noncash expense (reversal of expense) for pension and other postretirement benefits.

+ References

+ Details

Name:	us-gaap_PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_InvestmentInFederalHomeLoanBankStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_InternalRevenueServiceIRSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) property shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($)
Significant Accounting Policies Disclosure [Line Items]
Other real estate owned, number of properties \| property	1
Other real estate owned	$ 75,000	$ 414,000
Anti-dilutive outstanding options \| shares	3,588	0
Investment in Federal Home Loan Bank Stock [Member]
Significant Accounting Policies Disclosure [Line Items]
Impairment charges		$ 0	$ 0
Internal Revenue Service (IRS) [Member]
Significant Accounting Policies Disclosure [Line Items]
Tax years subject to examination	2020 2019 2018
State and Local Jurisdiction [Member]
Significant Accounting Policies Disclosure [Line Items]
Tax years subject to examination	2020 2019 2018
Tax years under examination		2018 2017 2016
Supplemental Executive Retirement Plan [Member]
Significant Accounting Policies Disclosure [Line Items]
Normal retirement age	65 years
Monthly benefit amount	$ 10,000
SERP plan expense	$ 597,000