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Namespace Prefix:	fsbc_
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Represents Loans And Leases Receivable Gross Amount Before Deferred Loan Origination Cost Increased.

No definition available.

Name:	fsbc_LoansAndLeasesReceivableGrossAmountBeforeDeferredLoanOriginationCostIncreased
Namespace Prefix:	fsbc_
Data Type:	xbrli:monetaryItemType
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Represents Loans And Leases Receivable Gross Amount Before Deferred Loan Origination Cost Percentage Increased.

No definition available.

Name:	fsbc_LoansAndLeasesReceivableGrossAmountBeforeDeferredLoanOriginationCostPercentageIncreased
Namespace Prefix:	fsbc_
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Represents the amount related to loans serviced for others.

No definition available.

Name:	fsbc_LoansServicedForOthers
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Represents the number of loans additional

No definition available.

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Represents number of Loans Newly categorized.

No definition available.

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Represents the number of loans partially payoffs.

No definition available.

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Represents the number of loans paying as agreed.

No definition available.

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Represents the number of loans payoffs.

No definition available.

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Number of nonaccrual loans.

No definition available.

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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.

No definition available.

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Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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Recorded Investment in financing receivables that are past due at the balance sheet date.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Name:	us-gaap_ServicingAssetAtFairValueAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix:
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Namespace Prefix:
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Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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Namespace Prefix:
Data Type:	na
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Namespace Prefix:
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