XML 79 R67.htm IDEA: XBRL DOCUMENT
v3.20.4

Loans and Allowance for Loan and Lease Losses - Summarizes of All COVID19 Loan Payment Deferment and the Percentage of Loans (Details) - COVID-19 [Member] $ in Thousands | Dec. 31, 2020 USD ($) DeferredLoan | Sep. 30, 2020 USD ($) DeferredLoan | Jun. 30, 2020 USD ($) DeferredLoan
--- | --- | --- | ---
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan | 110 | 153 | 864
As of December 31, 2020 | $ | $ 8,061 | $ 18,416 | $ 95,244
As of December 31, 2020 | 1.20% | 2.90% | 16.50%
Construction, Land Development and Other Land Loans [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan |  | 1 | 7
As of December 31, 2020 | $ |  | $ 2,259 | $ 4,544
As of December 31, 2020 |  | 6.40% | 14.50%
Secured by 1-4 Family Residential Properties [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan | 6 | 8 | 50
As of December 31, 2020 | $ | $ 314 | $ 398 | $ 9,474
As of December 31, 2020 | 0.40% | 0.40% | 10.20%
Secured By Multi family Residential Properties [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan |  |  | 12
As of December 31, 2020 | $ |  |  | $ 29,726
As of December 31, 2020 |  |  | 60.90%
Secured By Non-farm Non residential Properties [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan | 6 | 10 | 49
As of December 31, 2020 | $ | $ 6,615 | $ 14,084 | $ 42,797
As of December 31, 2020 | 3.60% | 7.70% | 26.60%
Commercial and Industrial Loans [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan | 2 | 2 | 9
As of December 31, 2020 | $ | $ 530 | $ 529 | $ 1,460
As of December 31, 2020 | 0.60% | 0.60% | 1.70%
Consumer Portfolio Segment | Direct Consumer [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan | 50 | 77 | 442
As of December 31, 2020 | $ | $ 201 | $ 284 | $ 2,188
As of December 31, 2020 | 0.70% | 0.90% | 6.60%
Consumer Portfolio Segment | Branch Retail [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan | 43 | 36 | 172
As of December 31, 2020 | $ | $ 336 | $ 353 | $ 1,856
As of December 31, 2020 | 1.00% | 1.10% | 5.60%
Consumer Portfolio Segment | Indirect Sales [Member] |  |  |
Financing Receivable Modifications [Line Items] |  |  |
As of December 31, 2020 | DeferredLoan | 3 | 19 | 123
As of December 31, 2020 | $ | $ 65 | $ 509 | $ 3,199
As of December 31, 2020 | 0.10% | 0.40% | 3.60%

X
- Definition Number of loans deferred. + References No definition available. + Details
Name: | fusb_NumberOfLoansDeferred
Namespace Prefix: | fusb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of portfolio balance. + References No definition available. + Details
Name: | fusb_PercentageOfPortfolioBalance
Namespace Prefix: | fusb_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Principal balance of loans deferred. + References No definition available. + Details
Name: | fusb_PrincipalBalanceOfLoansDeferred
Namespace Prefix: | fusb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_UnusualOrInfrequentItemAxis=fusb_COVID19Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fusb_SecuredBy1To4FamilyResidentialPropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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