XML 56 R46.htm IDEA: XBRL DOCUMENT v3.23.3

Loans and Allowance for Credit Losses - Schedule of Loan Portfolio (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Loans	$ 815,300	$ 773,873
Equipment Financing Leases [Member]
Loans	$ 10,200	$ 10,300

X

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481990/310-10-45-2

+ Details

Name:	us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=fusb_EquipmentFinancingLeasesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: