XML 127 R116.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Commitments and Contingencies - SBA Recourse Reserve (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract] |  |
Beginning balance | $ 955 | $ 441
SBA (benefit) recourse | (104) | 775
Charge-offs, net | (206) | (261)
Ending balance | $ 645 | $ 955

X
- Definition SBA Recourse Provision (Benefit) + References No definition available. + Details
Name: | fbiz_SBARecourseProvisionBenefit
Namespace Prefix: | fbiz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition SBA Recourse Reserve + References No definition available. + Details
Name: | fbiz_SBARecourseReserve
Namespace Prefix: | fbiz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition SBA Loan Charge Offs, Net + References No definition available. + Details
Name: | fbiz_SbaLoanChargeOffsNet
Namespace Prefix: | fbiz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration