XML 71 R63.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value Disclosures (Fair Value by Balance Sheet Groupings) (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Dec. 31, 2013
Financial assets:        
Cash and cash equivalents, carrying amount $ 141,887us-gaap_CashAndCashEquivalentsAtCarryingValue $ 103,237us-gaap_CashAndCashEquivalentsAtCarryingValue $ 76,396us-gaap_CashAndCashEquivalentsAtCarryingValue $ 81,286us-gaap_CashAndCashEquivalentsAtCarryingValue
Securities available-for-sale, carrying amount 142,951us-gaap_AvailableForSaleSecuritiesDebtSecurities 144,698us-gaap_AvailableForSaleSecuritiesDebtSecurities    
Securities held-to-maturity, carrying value 40,599us-gaap_HeldToMaturitySecurities 41,563us-gaap_HeldToMaturitySecurities    
Loans and leases receivable, net amount, carrying amount 1,279,846us-gaap_LoansAndLeasesReceivableNetReportedAmount 1,265,098us-gaap_LoansAndLeasesReceivableNetReportedAmount    
Federal Home Loan Bank stock, carrying amount 2,798us-gaap_FederalHomeLoanBankStock 2,340us-gaap_FederalHomeLoanBankStock    
Cash surrender value of life insurance, carrying amount 27,548us-gaap_BankOwnedLifeInsurance 27,314us-gaap_BankOwnedLifeInsurance    
Accrued interest receivable, carrying amount 4,146us-gaap_InterestReceivable 3,932us-gaap_InterestReceivable    
Interest rate swaps - assets, carrying amount 956us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue 575us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue    
Cash and cash equivalents, fair value 141,887us-gaap_CashAndCashEquivalentsFairValueDisclosure 103,227us-gaap_CashAndCashEquivalentsFairValueDisclosure    
Securities available-for-sale, fair value 142,951us-gaap_AvailableForSaleSecurities 144,698us-gaap_AvailableForSaleSecurities    
Loans held-for-sale 2,396us-gaap_LoansReceivableHeldForSaleAmount 1,340us-gaap_LoansReceivableHeldForSaleAmount    
Held-to-maturity Securities, fair value 41,147us-gaap_HeldToMaturitySecuritiesFairValue 41,694us-gaap_HeldToMaturitySecuritiesFairValue    
Loans and lease receivables, net, fair value 1,310,067us-gaap_LoansReceivableFairValueDisclosure 1,285,162us-gaap_LoansReceivableFairValueDisclosure    
Federal Home Loan Bank stock, fair value 2,798us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure 2,340us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure    
Cash surrender value of life insurance, fair value 27,548us-gaap_CashSurrenderValueFairValueDisclosure 27,314us-gaap_CashSurrenderValueFairValueDisclosure    
Accrued interest receivable, fair value 4,146fbiz_AccruedInterestReceivableFairValueDisclosure 3,932fbiz_AccruedInterestReceivableFairValueDisclosure    
Interest rate swaps - assets, fair value 956fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure 575fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure    
Financial liabilities:        
Deposits, carrying amount 1,485,801us-gaap_Deposits 1,438,268us-gaap_Deposits    
Federal Home Loan Bank and other borrowings, carrying amount 34,448fbiz_FederalHomeLoanBankAndOtherBorrowings 33,994fbiz_FederalHomeLoanBankAndOtherBorrowings    
Junior subordinated notes, carrying amount 10,315us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust 10,315us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust    
Interest rate swaps - liabilities, carrying amount 956us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue 575us-gaap_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue    
Accrued interest payable, carrying amount 1,744us-gaap_InterestPayableCurrentAndNoncurrent 1,574us-gaap_InterestPayableCurrentAndNoncurrent    
Standby letters of credit, carrying amount 128us-gaap_LettersOfCreditOutstandingAmount 192us-gaap_LettersOfCreditOutstandingAmount    
Commitments to extend credit, carrying amount 0fbiz_CommitmentstoExtendCreditCarryingAmount 0fbiz_CommitmentstoExtendCreditCarryingAmount    
Deposits, fair value 1,489,399us-gaap_DepositsFairValueDisclosure 1,440,248us-gaap_DepositsFairValueDisclosure    
Federal Home Loan Bank and other borrowings fair value 35,080fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure 34,590fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure    
Junior subordinated notes, fair value 7,086us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations 7,101us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations    
Interest rate swaps - liabilities, fair value 956fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure 575fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure    
Accrued interest payable, fair value 1,744us-gaap_AccruedLiabilitiesFairValueDisclosure 1,574us-gaap_AccruedLiabilitiesFairValueDisclosure    
Standby letters of credit, fair value 128fbiz_StandbyLettersOfCreditFairValueDisclosure 192fbiz_StandbyLettersOfCreditFairValueDisclosure    
Fair Value Measurements - Level 1 Inputs        
Financial assets:        
Cash and cash equivalents, fair value 120,127us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
85,937us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Securities available-for-sale, fair value 0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Loans held-for-sale 0us-gaap_LoansReceivableHeldForSaleAmount
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0us-gaap_LoansReceivableHeldForSaleAmount
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Held-to-maturity Securities, fair value 0us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Loans and lease receivables, net, fair value 0us-gaap_LoansReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0us-gaap_LoansReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Federal Home Loan Bank stock, fair value 0us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Cash surrender value of life insurance, fair value 27,548us-gaap_CashSurrenderValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
27,314us-gaap_CashSurrenderValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Accrued interest receivable, fair value 4,146fbiz_AccruedInterestReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
3,932fbiz_AccruedInterestReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Interest rate swaps - assets, fair value 0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Financial liabilities:        
Deposits, fair value 939,576us-gaap_DepositsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
884,292us-gaap_DepositsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Federal Home Loan Bank and other borrowings fair value 0fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Junior subordinated notes, fair value 0us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Interest rate swaps - liabilities, fair value 0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Accrued interest payable, fair value 1,744us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
1,574us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Standby letters of credit, fair value 0fbiz_StandbyLettersOfCreditFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
0fbiz_StandbyLettersOfCreditFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
   
Fair Value Measurements - Level 2 Inputs        
Financial assets:        
Cash and cash equivalents, fair value 6,410us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
6,890us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Securities available-for-sale, fair value 142,951us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
144,698us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Loans held-for-sale 2,396us-gaap_LoansReceivableHeldForSaleAmount
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
1,340us-gaap_LoansReceivableHeldForSaleAmount
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Held-to-maturity Securities, fair value 41,147us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
41,694us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Loans and lease receivables, net, fair value 6,739us-gaap_LoansReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
7,025us-gaap_LoansReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Federal Home Loan Bank stock, fair value 0us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Cash surrender value of life insurance, fair value 0us-gaap_CashSurrenderValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_CashSurrenderValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Accrued interest receivable, fair value 0fbiz_AccruedInterestReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0fbiz_AccruedInterestReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Interest rate swaps - assets, fair value 956fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
575fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Financial liabilities:        
Deposits, fair value 549,823us-gaap_DepositsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
555,956us-gaap_DepositsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Federal Home Loan Bank and other borrowings fair value 35,080fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
34,590fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Junior subordinated notes, fair value 0us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Interest rate swaps - liabilities, fair value 956fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
575fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Accrued interest payable, fair value 0us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Standby letters of credit, fair value 0fbiz_StandbyLettersOfCreditFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0fbiz_StandbyLettersOfCreditFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
   
Fair Value Measurements - Level 3 Inputs        
Financial assets:        
Cash and cash equivalents, fair value 15,350us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
10,400us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Securities available-for-sale, fair value 0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Loans held-for-sale 0us-gaap_LoansReceivableHeldForSaleAmount
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_LoansReceivableHeldForSaleAmount
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Held-to-maturity Securities, fair value 0us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Loans and lease receivables, net, fair value 1,303,328us-gaap_LoansReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
1,278,137us-gaap_LoansReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Federal Home Loan Bank stock, fair value 2,798us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
2,340us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Cash surrender value of life insurance, fair value 0us-gaap_CashSurrenderValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_CashSurrenderValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Accrued interest receivable, fair value 0fbiz_AccruedInterestReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0fbiz_AccruedInterestReceivableFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Interest rate swaps - assets, fair value 0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Financial liabilities:        
Deposits, fair value 0us-gaap_DepositsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_DepositsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Federal Home Loan Bank and other borrowings fair value 0fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0fbiz_FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Junior subordinated notes, fair value 7,086us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
7,101us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Interest rate swaps - liabilities, fair value 0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0fbiz_InterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValueFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Accrued interest payable, fair value 0us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_AccruedLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
   
Standby letters of credit, fair value $ 128fbiz_StandbyLettersOfCreditFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
$ 192fbiz_StandbyLettersOfCreditFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member