XML 60 R48.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Interest Bearing Deposits - Interest Expense Recognized on Interest-bearing Deposits (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023
Interest-bearing Deposits |  |  |  |
Interest-bearing transaction accounts | $ 1,104 | $ 825 | $ 2,230 | $ 1,258
Savings accounts | 856 | 758 | 1,718 | 1,303
Money market accounts | 13,388 | 8,136 | 25,543 | 13,572
Time accounts, $250 or more | 2,412 | 2,634 | 6,235 | 4,597
Other time accounts | 957 | 1,616 | 2,502 | 2,617
Total interest expense on interest-bearing deposits | $ 18,717 | $ 13,969 | 38,228 | $ 23,347
Time deposits minimum |  |  | $ 250 |

X
- Definition Interest-bearing Deposits + References No definition available. + Details
Name: | fsbc_DisclosureInterestbearingDepositsAbstract
Namespace Prefix: | fsbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest Expense Domestic Deposit Liabilities Time Deposit 250000, Minimum + References No definition available. + Details
Name: | fsbc_InterestExpenseDomesticDepositLiabilitiesTimeDeposit250000Minimum
Namespace Prefix: | fsbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest Expense Domestic Deposit Liabilities Time Deposit 250000 Or More + References No definition available. + Details
Name: | fsbc_InterestExpenseDomesticDepositLiabilitiesTimeDeposit250000OrMore
Namespace Prefix: | fsbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Aggregate amount of interest expense on all deposits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 + Details
Name: | us-gaap_InterestExpenseDeposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest expense on domestic checking deposit liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 + Details
Name: | us-gaap_InterestExpenseDomesticDepositLiabilitiesChecking
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest expense on domestic money market demand account deposit liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 + Details
Name: | us-gaap_InterestExpenseDomesticDepositLiabilitiesMoneyMarket
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest expense on domestic time deposit liabilities other than certificates of liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 + Details
Name: | us-gaap_InterestExpenseDomesticDepositLiabilitiesOtherTimeDeposit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest expense on domestic savings deposit liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 + Details
Name: | us-gaap_InterestExpenseDomesticDepositLiabilitiesSavings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration