Fair Value, Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Carrying Value [Member]
Financial Assets [Abstract]
Loans receivable held for sale	$ 40,653	$ 0
Loans receivable held for investment	361,793	397,847
Financial Liabilities [Abstract]
Time Deposits	147,703	190,235
Federal Home Loan Bank advances	115,500	84,000
Junior subordinated debentures	3,570	4,335
Fair Value [Member]
Financial Assets [Abstract]
Loans receivable held for sale	40,667	0
Loans receivable held for investment	366,160	404,923
Financial Liabilities [Abstract]
Time Deposits	148,380	190,353
Federal Home Loan Bank advances	119,334	84,997
Junior subordinated debentures	3,029	3,734
Level 1 [Member] \| Fair Value [Member]
Financial Assets [Abstract]
Loans receivable held for sale	0	0
Loans receivable held for investment	0	0
Financial Liabilities [Abstract]
Time Deposits	0	0
Federal Home Loan Bank advances	0	0
Junior subordinated debentures	0	0
Level 2 [Member] \| Fair Value [Member]
Financial Assets [Abstract]
Loans receivable held for sale	40,667	0
Loans receivable held for investment	0	0
Financial Liabilities [Abstract]
Time Deposits	148,380	190,353
Federal Home Loan Bank advances	119,334	84,997
Junior subordinated debentures	0	0
Level 3 [Member] \| Fair Value [Member]
Financial Assets [Abstract]
Loans receivable held for sale	0	0
Loans receivable held for investment	366,160	404,923
Financial Liabilities [Abstract]
Time Deposits	0	0
Federal Home Loan Bank advances	0	0
Junior subordinated debentures	$ 3,029	$ 3,734

Fair value portion of time deposit liabilities held by the entity.

No definition available.

Name:	byfc_TimeDepositsFairValueDisclosure
Namespace Prefix:	byfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

- Definition

Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

+ 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 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

+ References

No definition available.

+ Details

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

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

+ Details

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

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: