v3.25.4
Regulatory Capital Requirements (Narrative) (Details)
12 Months Ended
Dec. 31, 2025
Regulatory Capital Requirements
Percentage of capital stock and surplus on secured basis
10.00%
X
- Definition
Percentage of Capital Stock and Surplus on Secured Basis.
+ References
No definition available.
+ Details
Name:
func_PercentageOfCapitalStockAndSurplusOnSecuredBasis
Namespace Prefix:
func_
Data Type:
dtr-types:percentItemType
Balance Type:
na
Period Type:
duration
X
- References
No definition available.
+ Details
Name:
us-gaap_BankingAndThriftInterestAbstract
Namespace Prefix:
us-gaap_
Data Type:
xbrli:stringItemType
Balance Type:
na
Period Type:
duration