Loans Receivable Held for Investment, Purchased Credit Deteriorated (PCD) Loans (Details) $ in Thousands	3 Months Ended
Mar. 31, 2024 USD ($) Loan	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Purchased Credit Deteriorated Loans [Abstract]
Number of acquired loans with evidence of credit deterioration of credit quality since origination at acquisition \| Loan	0
Loans receivable	$ 926,497		$ 880,457
Purchased Credit Impaired Loans [Member]
Discount on Purchased Credit Deteriorated Loans [Roll Forward]
Balance at the beginning of the period	2	$ 27
Deduction due to payoffs	0	(12)
Accretion	(2)	(4)
Balance at the end of the period	0	$ 11
Real Estate [Member] \| Purchased Credit Impaired Loans [Member]
Purchased Credit Deteriorated Loans [Abstract]
Loans receivable	47		47
Real Estate [Member] \| Single-Family [Member] \| Purchased Credit Impaired Loans [Member]
Purchased Credit Deteriorated Loans [Abstract]
Loans receivable	0		0
Commercial - Other [Member] \| Purchased Credit Impaired Loans [Member]
Purchased Credit Deteriorated Loans [Abstract]
Loans receivable	$ 47		$ 47

Number of acquired loans with evidence of credit deterioration of credit quality since origination at acquisition.

No definition available.

Name:	byfc_AcquiredLoansWithEvidenceOfCreditDeteriorationOfCreditQualitySinceOriginationAtAcquisition
Namespace Prefix:	byfc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of financing receivable purchased with credit deterioration.

+ References

No definition available.

+ Details

Name:	byfc_FinancingReceivablePurchasedWithCreditDeterioration
Namespace Prefix:	byfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of deduction due to payoff of financing receivable purchased with credit deterioration.

+ References

No definition available.

+ Details

Name:	byfc_FinancingReceivablePurchasedWithCreditDeteriorationDeductionDueToPayoff
Namespace Prefix:	byfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

Name:	byfc_PurchasedCreditDeterioratedLoansAbstract
Namespace Prefix:	byfc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount of discount (premium) attributable to other factors on financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 19
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-19

+ Details

Name:	us-gaap_FinancingReceivablePurchasedWithCreditDeteriorationDiscountPremium
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(5)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481990/310-10-45-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-5

+ Details

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

- Details

Name:	us-gaap_CreditLossStatusAxis=us-gaap_FinancialAssetAcquiredWithCreditDeteriorationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=byfc_SingleFamilyLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: