XML 125 R114.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Commitments and Contingencies - Lending Related And Other Commitments (Details) - USD ($) $ in Thousands | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Commitments to extend credit, primarily commercial loans |  |
Lending Related Commitments By Type [LineItems] |  |
Lending related commitments | $ 1,046,598 | $ 1,198,031
Standby letters of credit |  |
Lending Related Commitments By Type [LineItems] |  |
Lending related commitments | $ 17,276 | $ 17,938

X
- Definition Lending related commitments by type lineItems. + References No definition available. + Details
Name: | fbiz_LendingRelatedCommitmentsByTypeLineitems
Namespace Prefix: | fbiz_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition LendingRelatedCommitments + References No definition available. + Details
Name: | fbiz_Lendingrelatedcommitments
Namespace Prefix: | fbiz_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | fbiz_LendingRelatedCommitmentsByTypeAxis=us-gaap_CommitmentsToExtendCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | fbiz_LendingRelatedCommitmentsByTypeAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |