XML 70 R64.htm IDEA: XBRL DOCUMENT
v3.24.1.1.u2

Borrowings - Schedule of Available Unused Lines of Credit (Details) - Unused lines of Credit [Member] - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 | Dec. 31, 2023
Correspondent Banks [Member] |  |  |
Short Term Debt [Line Items] |  |  |
Collateral Requirements |  | None |
Available lines of credit |  | $ 48.0 | $ 48.0
FHLB Advances [Member] |  |  |
Short Term Debt [Line Items] |  |  |
Collateral Requirements | [1] | Subject to collateral |
Available lines of credit | [1] | $ 276.8 | 279.4
FRB [Member] |  |  |
Short Term Debt [Line Items] |  |  |
Collateral Requirements | [2] | Subject to collateral |
Available lines of credit | [2] | $ 158.8 | $ 161.7
[1] | These amounts represent the total remaining credit the Company has from the FHLB, but this credit can only be utilized to the extent that underlying collateral exists. The total lendable collateral value of assets pledged (including loans and investment securities) associated with FHLB advances and letters of credit totaled $60.9 million and $61.7 million as of March 31, 2024 and December 31, 2023, respectively. The Company’s collateral exposure with the FHLB in the form of advances and letters of credit was $45.0 million and $40.0 million as of March 31, 2024 and December 31, 2023, respectively, leaving an excess of collateral of $15.9 million and $21.7 million, respectively, available to utilize for additional credit as of the respective dates. The Company also has the ability to pledge additional assets to increase the availability of borrowings.
[2] | The Company has access to the FRB's discount window, which allows borrowing on pledged collateral that includes eligible investment securities and loans under 90-day terms. The amounts shown in the table represent the Company's unused borrowing capacity as of the applicable date based on collateral pledged to the FRB's discount window.

X
- Definition Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13(3)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 470 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480876/942-470-45-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22 (b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Describes the collateral pledged in support of Federal Home Loan Bank advances outstanding as of the Balance Sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 470 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480876/942-470-45-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480848/942-470-50-3 + Details
Name: | us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresDescriptionOfCollateralPledged
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_UnusedLinesOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShortTermDebtTypeAxis=fusb_CorrespondentBanksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShortTermDebtTypeAxis=us-gaap_FederalHomeLoanBankAdvancesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShortTermDebtTypeAxis=us-gaap_FederalReserveBankAdvancesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |