XML 67 R55.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Commitments and Contingencies - Narrative (Details) $ in Thousands | Jun. 30, 2024 USD ($) deposit_relationship | Mar. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Jun. 30, 2023 USD ($) | Mar. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
--- | --- | --- | --- | --- | --- | ---
Other Commitments [Line Items] |  |  |  |  |  |
Allowance for credit loss | $ 35,406 | $ 34,653 | $ 34,431 | $ 33,984 | $ 34,172 | $ 28,389
Real estate related loans (in percent) | 89.76% |  | 92.30% |  |  |
Number of deposits | deposit_relationship | 99 |  |  |  |  |
Deposits over five million, total | $ 5,000 |  |  |  |  |
Deposits over five million, amount | $ 1,900,000 |  |  |  |  |
Percentage of deposits over five million deposits (in percent) | 59.53% |  |  |  |  |
Largest single deposit | $ 227,700 |  |  |  |  |
Percentage of largest single deposit to total deposits (in percent) | 7.23% |  |  |  |  |
Uninsured amount | $ 23,700 |  | $ 22,300 |  |  |
Unfunded Loan Commitment |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Allowance for credit loss | $ 1,147 | $ 1,097 | $ 1,247 | $ 1,547 | $ 1,217 | $ 125

X
- Definition Deposits, $5 Million Or More, Amount + References No definition available. + Details
Name: | fsbc_Deposits5MillionOrMoreAmount
Namespace Prefix: | fsbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deposits, $5 Million Or More, Number Of Deposit Relationships + References No definition available. + Details
Name: | fsbc_Deposits5MillionOrMoreNumberOfDepositRelationships
Namespace Prefix: | fsbc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Deposits, $5 Million Or More, Per Deposit + References No definition available. + Details
Name: | fsbc_Deposits5MillionOrMorePerDeposit
Namespace Prefix: | fsbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Largest Single Deposit + References No definition available. + Details
Name: | fsbc_LargestSingleDeposit
Namespace Prefix: | fsbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage of Deposits over $5 Million to Deposits + References No definition available. + Details
Name: | fsbc_PercentageOfDepositsOver5MillionToDeposits
Namespace Prefix: | fsbc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of Largest Single Deposit to Total Deposits + References No definition available. + Details
Name: | fsbc_PercentageOfLargestSingleDepositToDeposits
Namespace Prefix: | fsbc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Real Estate Related Loans Percentage + References No definition available. + Details
Name: | fsbc_RealEstateRelatedLoansPercentage
Namespace Prefix: | fsbc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation. + References No definition available. + Details
Name: | us-gaap_CashUninsuredAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-11B Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph c -Publisher SEC Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph a -Subparagraph (1) -Publisher SEC Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph a -Subparagraph (3) -Publisher SEC Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -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 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(7)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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_OtherCommitmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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