XML 125 R112.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract] |  |  |
SBA Loans, Probability of Future Losses | $ 2,800 | $ 1,800 |
SBA Recourse Provision | 2,240 | 2,068 | $ 0
Accrued credit losses for financial instruments with off-balance-sheet risk | $ 0 | $ 0 |

X
- Definition Accrued Credit Losses for Financial Instruments with Off-balance-sheet Risk + References No definition available. + Details
Name: | fbiz_AccruedCreditLossesForFinancialInstrumentsWithOffBalanceSheetRisk
Namespace Prefix: | fbiz_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition SBA Loans, Probability of Future Losses + References No definition available. + Details
Name: | fbiz_SBALoansProbabilityofFutureLosses
Namespace Prefix: | fbiz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition SBA Recourse Provision + References No definition available. + Details
Name: | fbiz_SBARecourseProvision
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