XML 42 R32.htm IDEA: XBRL DOCUMENT
v3.25.3

Note 4 - Loans - Schedule of Allowance for Credit Loss (Details) - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024
Beginning balance | $ 2,590,950 | $ 2,747,949 | $ 2,620,949 | $ 2,785,949 | $ 2,785,949
Provision for (recovery) of credit losses | (50,000) | 0 | (79,999) | (38,000) |
Loans charged off | 0 | 0 | 0 | 0 |
Recoveries | 0 | 0 | 0 | 0 |
Total ending allowance balance | 2,540,950 | 2,747,949 | 2,540,950 | 2,747,949 | 2,620,949
Commercial and Industrial [Member] |  |  |  |  |
Beginning balance | 24,340 | 33,221 | 20,000 | 22,000 | 22,000
Provision for (recovery) of credit losses | (6,563) | 536 | (2,223) | 11,757 |
Loans charged off | 0 | 0 | 0 | 0 | 0
Recoveries | 0 | 0 | 0 | 0 |
Total ending allowance balance | 17,777 | 33,757 | 17,777 | 33,757 | 20,000
Consumer Portfolio Segment [Member] |  |  |  |  |
Beginning balance | 223 | 0 | 0 | 0 | 0
Provision for (recovery) of credit losses | (36) | 0 | 187 | 0 |
Loans charged off | 0 | 0 | 0 | 0 | 0
Recoveries | 0 | 0 | 0 | 0 |
Total ending allowance balance | 187 | 0 | 187 | 0 | 0
Real Estate Loan [Member] | Residential Portfolio Segment [Member] |  |  |  |  |
Beginning balance | 1,660,885 | 1,836,909 | 1,680,949 | 1,851,969 | 1,851,969
Provision for (recovery) of credit losses | (41,284) | (10,371) | (61,348) | (25,431) |
Loans charged off | 0 | 0 | 0 | 0 | 0
Recoveries | 0 | 0 | 0 | 0 |
Total ending allowance balance | 1,619,601 | 1,826,538 | 1,619,601 | 1,826,538 | 1,680,949
Real Estate Loan [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |  |
Beginning balance | 533,874 | 456,898 | 508,000 | 437,180 | 437,180
Provision for (recovery) of credit losses | 22,684 | 5,417 | 48,558 | 25,135 |
Loans charged off | 0 | 0 | 0 | 0 | 0
Recoveries | 0 | 0 | 0 | 0 |
Total ending allowance balance | 556,558 | 462,315 | 556,558 | 462,315 | 508,000
Real Estate Loan [Member] | Multi-Family Real Estate [Member] |  |  |  |  |
Beginning balance | 278,916 | 315,495 | 289,000 | 317,300 | 317,300
Provision for (recovery) of credit losses | 9,125 | (2,274) | (959) | (4,079) |
Loans charged off | 0 | 0 | 0 | 0 | 0
Recoveries | 0 | 0 | 0 | 0 |
Total ending allowance balance | 288,041 | 313,221 | 288,041 | 313,221 | 289,000
Real Estate Loan [Member] | Construction Loans [Member] |  |  |  |  |
Beginning balance | 92,712 | 105,426 | 123,000 | 157,500 | 157,500
Provision for (recovery) of credit losses | (33,926) | 6,692 | (64,214) | (45,382) |
Loans charged off | 0 | 0 | 0 | 0 | 0
Recoveries | 0 | 0 | 0 | 0 |
Total ending allowance balance | $ 58,786 | $ 112,118 | $ 58,786 | $ 112,118 | $ 123,000

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476148/220-40-50-22 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=bsbk_CommercialAndIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RealEstateLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=bsbk_MultifamilyRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |