$FBIZ
FIRST BUSINESS FINANCIAL SERVICES, INC. Stock $fbiz

$fbiz Overview Financials Valuation SEC Filings Company Website

2024 Q2 Form 10-Q Financial Statement

#000152195124000033 Filed on April 26, 2024

Income Statement

Concept	2024 Q2	2024 Q1
Revenue	$57.91M	$55.78M
YoY Change	22.79%	32.61%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$979.0K	$791.0K
YoY Change	1.98%	-13.27%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$27.37M	$26.27M
YoY Change	40.98%	71.05%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$12.37M	$10.60M
YoY Change	-67.95%	-10.07%
Income Tax	$1.917M	$1.752M
% Of Pretax Income	15.49%	16.53%
Net Earnings	$10.46M	$8.415M
YoY Change	-70.67%	-6.28%
Net Earnings / Revenue	18.06%	15.09%
Basic Earnings Per Share	$1.23	$1.04
Diluted Earnings Per Share	$1.23	$1.04
COMMON SHARES
Basic Shares Outstanding	8.289M shares	8.307M shares
Diluted Shares Outstanding	8.113M	8.125M shares

Balance Sheet

Concept	2024 Q2	2024 Q1
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$81.08M	$72.04M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$6.381M	$12.57M
YoY Change	-47.45%	154.71%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$56.31M	$49.43M
YoY Change	47.62%	48.63%
Other Assets	$8.910M	$8.267M
YoY Change	-24.02%	-27.85%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$3.617B	$3.531B
YoY Change	10.76%	11.6%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$28.67M	$26.65M
YoY Change	22.03%	31.3%
Accrued Expenses	$8.361M	$8.664M
YoY Change	-11.98%	-11.79%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$37.03M	$35.31M
YoY Change	12.24%	17.24%
LONG-TERM LIABILITIES
Long-Term Debt	$327.9M	$49.47M
YoY Change	852.85%	43.97%
Other Long-Term Liabilities	$61.82M	$61.13M
YoY Change	1.1%	24.73%
Total Long-Term Liabilities	$389.7M	$110.6M
YoY Change	307.8%	32.66%
TOTAL LIABILITIES
Total Short-Term Liabilities	$37.03M	$35.31M
Total Long-Term Liabilities	$389.7M	$110.6M
Total Liabilities	$3.312B	$3.234B
YoY Change	10.65%	11.59%
SHAREHOLDERS EQUITY
Retained Earnings	$245.4M	$237.3M
YoY Change	14.03%	13.52%
Common Stock	$95.00K	$91.41M
YoY Change	-99.89%	3.56%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$31.37M	$30.71M
YoY Change	4.27%	5.82%
Treasury Stock Shares
Shareholders Equity	$305.2M	$297.8M
YoY Change
Total Liabilities & Shareholders Equity	$3.617B	$3.531B
YoY Change	10.76%	11.6%

Cashflow Statement

Concept	2024 Q2	2024 Q1
OPERATING ACTIVITIES
Net Income	$10.46M	$8.415M
YoY Change	-70.67%	-6.28%
Depreciation, Depletion And Amortization	$979.0K	$791.0K
YoY Change	1.98%	-13.27%
Cash From Operating Activities	$13.05M	$8.683M
YoY Change	3.97%	-12.37%
INVESTING ACTIVITIES
Capital Expenditures	$399.0K	$397.0K
YoY Change	-12.69%	-50.25%
Acquisitions
YoY Change
Other Investing Activities	-$76.59M	-$82.33M
YoY Change	-52.83%	-28.75%
Cash From Investing Activities	-$76.99M	-$82.73M
YoY Change	-52.71%	-28.89%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	72.98M	6.575M
YoY Change	-5.35%	-96.53%
NET CHANGE
Cash From Operating Activities	13.05M	8.683M
Cash From Investing Activities	-76.99M	-82.73M
Cash From Financing Activities	72.98M	6.575M
Net Change In Cash	9.040M	-67.47M
YoY Change	-112.36%	-181.01%
FREE CASH FLOW
Cash From Operating Activities	$13.05M	$8.683M
Capital Expenditures	$399.0K	$397.0K
Free Cash Flow	$12.65M	$8.286M
YoY Change	4.6%	-9.05%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2024Q1	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q1
CY2024Q1	dei	Amendment Flag AmendmentFlag	false
CY2023Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	32348000	usd
CY2024Q1	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2024Q1	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2024
CY2024Q1	dei	Document Quarterly Report DocumentQuarterlyReport	true
CY2024Q1	dei	Document Period End Date DocumentPeriodEndDate	2024-03-31
CY2024Q1	dei	Entity Registrant Name EntityRegistrantName	FIRST BUSINESS FINANCIAL SERVICES, INC.
CY2024Q1	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	WI
CY2024Q1	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	39-1576570
CY2024Q1	dei	Entity Address Address Line1 EntityAddressAddressLine1	401 Charmany Drive
CY2024Q1	dei	Entity Address City Or Town EntityAddressCityOrTown	Madison
CY2024Q1	dei	Security12b Title Security12bTitle	Common Stock, $0.01 par value
CY2024Q1	dei	Trading Symbol TradingSymbol	FBIZ
CY2024Q1	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2024Q1	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2024Q1	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2024Q1	dei	Entity Filer Category EntityFilerCategory	Accelerated Filer
CY2024Q1	dei	Entity Small Business EntitySmallBusiness	true
CY2024Q1	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2024Q1	dei	Entity Shell Company EntityShellCompany	false
CY2024Q2	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	8288707	shares
CY2024Q1	us-gaap	Cash And Due From Banks CashAndDueFromBanks	25056000	usd
CY2024Q1	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	46984000	usd
CY2023Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	107162000	usd
CY2024Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	72040000	usd
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	139510000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	314114000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	297006000	usd
CY2024Q1	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	8131000	usd
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	8503000	usd
CY2024Q1	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	4855000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	4589000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	32799000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	31275000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2878065000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2818986000	usd
CY2024Q1	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	6268000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	6190000	usd
CY2024Q1	us-gaap	Foreclosed Assets ForeclosedAssets	317000	usd
CY2023Q4	us-gaap	Foreclosed Assets ForeclosedAssets	247000	usd
CY2024Q1	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	6297000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	6559000	usd
CY2024Q1	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	55948000	usd
CY2023Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	55536000	usd
CY2024Q1	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	13326000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	12042000	usd
CY2023Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	12023000	usd
CY2024Q1	us-gaap	Derivative Assets DerivativeAssets	69703000	usd
CY2023Q4	us-gaap	Derivative Assets DerivativeAssets	55597000	usd
CY2024Q1	us-gaap	Other Assets OtherAssets	90344000	usd
CY2023Q4	us-gaap	Other Assets OtherAssets	91058000	usd
CY2024Q1	us-gaap	Assets Assets	3531358000	usd
CY2023Q4	us-gaap	Assets Assets	3507846000	usd
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CY2023Q4	us-gaap	Deposits Deposits	2796779000	usd
CY2023Q4	fbiz	Federal Home Loan Bank And Other Borrowings FederalHomeLoanBankAndOtherBorrowings	330916000	usd
CY2024Q1	us-gaap	Operating Lease Liability OperatingLeaseLiability	8664000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	8954000	usd
CY2024Q1	us-gaap	Derivative Liabilities DerivativeLiabilities	61133000	usd
CY2023Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	51949000	usd
CY2024Q1	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	12500	shares
CY2024Q1	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	12500	shares
CY2024Q1	us-gaap	Preferred Stock Dividend Rate Percentage PreferredStockDividendRatePercentage	0.07
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CY2024Q1	us-gaap	Preferred Stock Value PreferredStockValue	11992000	usd
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CY2024Q1	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
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CY2024Q1	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	25000000	shares
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	25000000	shares
CY2024Q1	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	9426316	shares
CY2023Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	9418463	shares
CY2024Q1	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	8306573	shares
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	8314778	shares
CY2024Q1	us-gaap	Common Stock Value CommonStockValue	95000	usd
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CY2024Q1	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	91312000	usd
CY2023Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	90616000	usd
CY2024Q1	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	237270000	usd
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	230728000	usd
CY2024Q1	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-12176000	usd
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-13717000	usd
CY2024Q1	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	1119743	shares
CY2023Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	1103685	shares
CY2024Q1	us-gaap	Treasury Stock Value TreasuryStockValue	30705000	usd
CY2023Q4	us-gaap	Treasury Stock Value TreasuryStockValue	30126000	usd
CY2024Q1	us-gaap	Stockholders Equity StockholdersEquity	297788000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	289588000	usd
CY2024Q1	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	3531358000	usd
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	3507846000	usd
CY2024Q1	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	51549000	usd
CY2023Q1	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	39814000	usd
CY2024Q1	dei	Document Transition Report DocumentTransitionReport	false
CY2024Q1	dei	Entity Address State Or Province EntityAddressStateOrProvince	WI
CY2024Q1	dei	City Area Code CityAreaCode	608
CY2024Q1	dei	Local Phone Number LocalPhoneNumber	238-8008
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CY2024Q1	us-gaap	Liabilities Liabilities	3233570000	usd
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CY2023Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	12500	shares
CY2024Q1	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	2794000	usd
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CY2024Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	55783000	usd
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CY2024Q1	fbiz	Interest Expense Federal Home Loan Bank And Other Borrowings InterestExpenseFederalHomeLoanBankAndOtherBorrowings	2435000	usd
CY2023Q1	fbiz	Interest Expense Federal Home Loan Bank And Other Borrowings InterestExpenseFederalHomeLoanBankAndOtherBorrowings	2929000	usd
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CY2023Q1	us-gaap	Interest Expense InterestExpense	15359000	usd
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CY2023Q1	us-gaap	Equipment Expense EquipmentExpense	295000	usd
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CY2024Q1	us-gaap	Noninterest Expense NoninterestExpense	23342000	usd
CY2023Q1	us-gaap	Noninterest Expense NoninterestExpense	21767000	usd
CY2024Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	10600000	usd
CY2023Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	11787000	usd
CY2024Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1752000	usd
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CY2023Q1	us-gaap	Net Income Loss NetIncomeLoss	8979000	usd
CY2024Q1	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	219000	usd
CY2023Q1	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	219000	usd
CY2024Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	8629000	usd
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CY2024Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.04
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CY2023Q1	us-gaap	Net Income Loss NetIncomeLoss	8979000	usd
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CY2024Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-8000	usd
CY2023Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	usd
CY2024Q1	fbiz	Other Comprehensive Income Loss Amortizationof Net Unrealized Losses Transferredto Heldto Maturityfrom Availablefor Salebeforetax OtherComprehensiveIncomeLossAmortizationofNetUnrealizedLossesTransferredtoHeldtoMaturityfromAvailableforSalebeforetax	1000	usd
CY2023Q1	fbiz	Other Comprehensive Income Loss Amortizationof Net Unrealized Losses Transferredto Heldto Maturityfrom Availablefor Salebeforetax OtherComprehensiveIncomeLossAmortizationofNetUnrealizedLossesTransferredtoHeldtoMaturityfromAvailableforSalebeforetax	2000	usd
CY2024Q1	fbiz	Unrealized Gains On Interest Rate Swaps UnrealizedGainsOnInterestRateSwaps	4922000	usd
CY2023Q1	fbiz	Unrealized Gains On Interest Rate Swaps UnrealizedGainsOnInterestRateSwaps	-1562000	usd
CY2024Q1	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	529000	usd
CY2023Q1	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	563000	usd
CY2024Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	1541000	usd
CY2023Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	1639000	usd
CY2024Q1	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	10389000	usd
CY2023Q1	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	10618000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	260640000	usd
CY2023Q1	us-gaap	Net Income Loss NetIncomeLoss	8979000	usd
CY2023Q1	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	1639000	usd
CY2023Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	634000	usd
CY2023Q1	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	27000	usd
CY2023Q1	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	219000	usd
CY2023Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.2275
CY2023Q1	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	1906000	usd
CY2023Q1	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	1860000	usd
CY2023Q1	us-gaap	Stockholders Equity StockholdersEquity	266581000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	289588000	usd
CY2024Q1	us-gaap	Net Income Loss NetIncomeLoss	8848000	usd
CY2024Q1	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	1541000	usd
CY2024Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	665000	usd
CY2024Q1	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	31000	usd
CY2024Q1	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	219000	usd
CY2024Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.2500
CY2024Q1	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	2087000	usd
CY2024Q1	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	579000	usd
CY2024Q1	us-gaap	Stockholders Equity StockholdersEquity	297788000	usd
CY2024Q1	us-gaap	Net Income Loss NetIncomeLoss	8848000	usd
CY2023Q1	us-gaap	Net Income Loss NetIncomeLoss	8979000	usd
CY2024Q1	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2268000	usd
CY2023Q1	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	312000	usd
CY2024Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2326000	usd
CY2023Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1561000	usd
CY2024Q1	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	791000	usd
CY2023Q1	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	912000	usd
CY2024Q1	us-gaap	Share Based Compensation ShareBasedCompensation	665000	usd
CY2023Q1	us-gaap	Share Based Compensation ShareBasedCompensation	634000	usd
CY2024Q1	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-10000	usd
CY2023Q1	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	0	usd
CY2024Q1	us-gaap	Gain Loss On Sale Of Leased Assets Net Operating Leases GainLossOnSaleOfLeasedAssetsNetOperatingLeases	0	usd
CY2023Q1	us-gaap	Gain Loss On Sale Of Leased Assets Net Operating Leases GainLossOnSaleOfLeasedAssetsNetOperatingLeases	-1000	usd
CY2024Q1	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	-8000	usd
CY2023Q1	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	0	usd
CY2024Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1296000	usd
CY2023Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	436000	usd
CY2024Q1	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	412000	usd
CY2023Q1	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	366000	usd
CY2024Q1	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	37213000	usd
CY2023Q1	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	27639000	usd
CY2024Q1	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	37142000	usd
CY2023Q1	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	28049000	usd
CY2024Q1	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	195000	usd
CY2023Q1	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	476000	usd
CY2024Q1	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-86000	usd
CY2023Q1	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-6000	usd
CY2024Q1	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	644000	usd
CY2023Q1	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	1690000	usd
CY2024Q1	fbiz	Excess Tax Benefit Expense From Share Based Compensation Operating Activities ExcessTaxBenefitExpenseFromShareBasedCompensationOperatingActivities	-90000	usd
CY2023Q1	fbiz	Excess Tax Benefit Expense From Share Based Compensation Operating Activities ExcessTaxBenefitExpenseFromShareBasedCompensationOperatingActivities	-137000	usd
CY2024Q1	us-gaap	Operating Lease Payments OperatingLeasePayments	385000	usd
CY2023Q1	us-gaap	Operating Lease Payments OperatingLeasePayments	355000	usd
CY2024Q1	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	-977000	usd
CY2023Q1	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	5738000	usd
CY2024Q1	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	-8263000	usd
CY2023Q1	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	1766000	usd
CY2024Q1	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	8683000	usd
CY2023Q1	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	9909000	usd
CY2024Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	11814000	usd
CY2023Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	4574000	usd
CY2024Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	369000	usd
CY2023Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	1169000	usd
CY2024Q1	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	7533000	usd
CY2023Q1	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	usd
CY2024Q1	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	39332000	usd
CY2023Q1	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	25924000	usd
CY2024Q1	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	61454000	usd
CY2023Q1	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	96356000	usd
CY2024Q1	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	600000	usd
CY2023Q1	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	650000	usd
CY2024Q1	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	0	usd
CY2023Q1	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	4000	usd
CY2024Q1	fbiz	Payments To Acquire Low Income Housing Entities PaymentsToAcquireLowIncomeHousingEntities	195000	usd
CY2023Q1	fbiz	Payments To Acquire Low Income Housing Entities PaymentsToAcquireLowIncomeHousingEntities	3090000	usd
CY2024Q1	fbiz	Distribution From Tax Credit Investments DistributionFromTaxCreditInvestments	57000	usd
CY2023Q1	fbiz	Distribution From Tax Credit Investments DistributionFromTaxCreditInvestments	0	usd
CY2024Q1	fbiz	Proceeds From Sale Of Tax Credit ProceedsFromSaleOfTaxCredit	731000	usd
CY2023Q1	fbiz	Proceeds From Sale Of Tax Credit ProceedsFromSaleOfTaxCredit	0	usd
CY2024Q1	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	1284000	usd
CY2023Q1	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	11644000	usd
CY2024Q1	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	0	usd
CY2023Q1	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	16369000	usd
CY2024Q1	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	397000	usd
CY2023Q1	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	798000	usd
CY2024Q1	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	30000	usd
CY2023Q1	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	0	usd
CY2024Q1	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-82728000	usd
CY2023Q1	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-116346000	usd
CY2024Q1	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	-41373000	usd
CY2023Q1	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	308635000	usd
CY2024Q1	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	95450000	usd
CY2023Q1	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	810350000	usd
CY2024Q1	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	146200000	usd
CY2023Q1	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	701470000	usd
CY2024Q1	us-gaap	Proceeds From Repayments Of Notes Payable ProceedsFromRepaymentsOfNotesPayable	52000	usd
CY2023Q1	us-gaap	Proceeds From Repayments Of Notes Payable ProceedsFromRepaymentsOfNotesPayable	-6069000	usd
CY2024Q1	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	2087000	usd
CY2023Q1	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	1906000	usd
CY2024Q1	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	219000	usd
CY2023Q1	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	219000	usd
CY2024Q1	fbiz	Proceeds From Issuance Of Common Stock Under The Employee Stock Purchase Plan ProceedsFromIssuanceOfCommonStockUnderTheEmployeeStockPurchasePlan	31000	usd
CY2023Q1	fbiz	Proceeds From Issuance Of Common Stock Under The Employee Stock Purchase Plan ProceedsFromIssuanceOfCommonStockUnderTheEmployeeStockPurchasePlan	27000	usd
CY2024Q1	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	579000	usd
CY2023Q1	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1860000	usd
CY2024Q1	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	6575000	usd
CY2023Q1	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	189728000	usd
CY2024Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	-67470000	usd
CY2023Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	83291000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	139510000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	102682000	usd
CY2024Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	72040000	usd
CY2023Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	185973000	usd
CY2024Q1	us-gaap	Interest Paid Net InterestPaidNet	26323000	usd
CY2023Q1	us-gaap	Interest Paid Net InterestPaidNet	13010000	usd
CY2024Q1	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	7000	usd
CY2023Q1	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-7000	usd
CY2024Q1	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	219000	usd
CY2023Q1	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	219000	usd
CY2024Q1	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	214000	usd
CY2023Q1	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	238000	usd
CY2024Q1	fbiz	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	8415000	usd
CY2023Q1	fbiz	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	8522000	usd
CY2024Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	8125319	shares
CY2023Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	8148525	shares
CY2024Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.04
CY2023Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.05
CY2024Q1	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	8415000	usd
CY2024Q1	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	157000	usd
CY2023Q1	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	0	usd
CY2024Q1	us-gaap	Use Of Estimates UseOfEstimates	Management of the Corporation is required to make estimates and assumptions which affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as reported amounts of revenues and expenses during the reporting period. Actual results could differ significantly from those estimates. Material estimates that could significantly change in the near-term include the value of securities and interest rate swaps, level of the allowance for credit losses, lease residuals, property under operating leases, goodwill, and income taxes.
CY2024Q1	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	Certain amounts in prior periods may have been reclassified to conform to the current presentation.
CY2024Q1	us-gaap	Net Income Loss NetIncomeLoss	8848000	usd
CY2023Q1	us-gaap	Net Income Loss NetIncomeLoss	8979000	usd
CY2023Q1	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	8522000	usd
CY2024Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	8125319	shares
CY2023Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	8148525	shares
CY2024Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.04
CY2023Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.05
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	274242	shares
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	196857	shares
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	29.32
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	89795	shares
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	34.96
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	96304	shares
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue	28.60
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	5255	shares
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	31.17
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	185093	shares
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	32.38
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	63050	shares
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	32.78
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	45475	shares
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue	29.09
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	8960	shares
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	32.91
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	193708	shares
CY2024Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	34.93
CY2024Q1	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	5179000	usd
CY2024Q1	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P2Y7M6D
CY2024Q1	fbiz	Employee Stock Purchase Plan Number Of Shares Authorized For Grant EmployeeStockPurchasePlanNumberOfSharesAuthorizedForGrant	250000	shares
CY2024Q1	fbiz	Employee Stock Purchase Program Percent Discount EmployeeStockPurchaseProgramPercentDiscount	0.90
CY2024Q1	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	913	shares
CY2024Q1	fbiz	Employee Stock Purchase Plan Number Of Shares Available For Grant EmployeeStockPurchasePlanNumberOfSharesAvailableForGrant	229725	shares
CY2024Q1	us-gaap	Share Based Compensation ShareBasedCompensation	665000	usd
CY2023Q1	us-gaap	Share Based Compensation ShareBasedCompensation	634000	usd
CY2024Q1	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	339042000	usd
CY2024Q1	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	598000	usd
CY2024Q1	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	25526000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	314114000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	319082000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1388000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	23464000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	297006000	usd
CY2024Q1	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	8131000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	0	usd
CY2024Q1	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	283000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	7848000	usd
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	8503000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	4000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	252000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	8255000	usd
CY2024Q1	fbiz	Numberofavailableforsalesecuritiessold Numberofavailableforsalesecuritiessold	5	securities
CY2023Q1	fbiz	Numberofavailableforsalesecuritiessold Numberofavailableforsalesecuritiessold	0	securities
CY2023Q1	fbiz	Numberofavailableforsalesecuritiessold Numberofavailableforsalesecuritiessold	0	securities
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	18655000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	18645000	usd
CY2024Q1	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	870000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	870000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	19674000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	18259000	usd
CY2024Q1	fbiz	Heldtomaturity Securities Debt Maturities Rolling Years Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearsTwoThroughFiveAmortizedCost	3147000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	3090000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	10553000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	9736000	usd
CY2024Q1	fbiz	Heldtomaturity Securities Debt Maturities Rolling Years Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearsSixThroughTenAmortizedCost	0	usd
CY2024Q1	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	0	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	21562000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	17924000	usd
CY2024Q1	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	0	usd
CY2024Q1	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	0	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	70444000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	64564000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	4017000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	3960000	usd
CY2024Q1	fbiz	Residential Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Amortized Cost ResidentialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateAmortizedCost	233172000	usd
CY2024Q1	fbiz	Residential Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Fair Value ResidentialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateFairValue	219101000	usd
CY2024Q1	fbiz	Residential Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Amortized Cost ResidentialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost	2110000	usd
CY2024Q1	fbiz	Residential Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Fair Value ResidentialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateFairValue	1980000	usd
CY2024Q1	fbiz	Commercial Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Amortized Cost CommercialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateAmortizedCost	35426000	usd
CY2024Q1	fbiz	Commercial Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Fair Value CommercialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateFairValue	30449000	usd
CY2024Q1	fbiz	Commercial Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Amortized Cost CommercialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost	2004000	usd
CY2024Q1	fbiz	Commercial Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Fair Value CommercialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateFairValue	1908000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	339042000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	314114000	usd
CY2024Q1	fbiz	Debt Securities Held To Maturity Maturity Without Single Maturity Date Amortized Cost DebtSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost	8131000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	7848000	usd
CY2024Q1	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	182	securities
CY2024Q1	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	159	securities
CY2024Q1	fbiz	Loans And Leases Transferred To Third Parties Total Principal Amount LoansAndLeasesTransferredToThirdPartiesTotalPrincipalAmount	34800000	usd
CY2024Q1	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	76914000	usd
CY2024Q1	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	763000	usd
CY2024Q1	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	178118000	usd
CY2024Q1	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	24763000	usd
CY2024Q1	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	255032000	usd
CY2024Q1	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	25526000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	47366000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	495000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	164447000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	22969000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	211813000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	23464000	usd
CY2024Q1	us-gaap	Held To Maturity Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions HeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions	25	securities
CY2024Q1	fbiz	Held To Maturity Securities In Continuous Unrealized Loss Positions12 Months Or Longer Qualitative Disclosure Number Of Positions HeldToMaturitySecuritiesInContinuousUnrealizedLossPositions12MonthsOrLongerQualitativeDisclosureNumberOfPositions	21	securities
CY2023Q1	us-gaap	Other Than Temporary Impairment Losses Investments Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsHeldtomaturitySecurities	0	usd
CY2024Q1	us-gaap	Other Than Temporary Impairment Losses Investments Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsHeldtomaturitySecurities	0	usd
CY2024Q1	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	1655000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	12000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	5653000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	271000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	7308000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	283000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	1424000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	4000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	6316000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	248000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	7740000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	252000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Before Fees Gross LoansAndLeasesReceivableBeforeFeesGross	2910590000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Before Fees Gross LoansAndLeasesReceivableBeforeFeesGross	2850018000	usd
CY2024Q1	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	32799000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	31275000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	-274000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	-243000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2878065000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2818986000	usd
CY2024Q1	fbiz	Guaranteed Portionof Sba Loans Soldto Third Parties Total GuaranteedPortionofSBALoansSoldtoThirdPartiesTotal	2100000	usd
CY2023Q1	fbiz	Guaranteed Portionof Sba Loans Soldto Third Parties Total GuaranteedPortionofSBALoansSoldtoThirdPartiesTotal	5000000	usd
CY2024Q1	fbiz	Totalamountofoutstanding Sb Aloanssold TotalamountofoutstandingSBAloanssold	80800000	usd
CY2023Q4	fbiz	Totalamountofoutstanding Sb Aloanssold TotalamountofoutstandingSBAloanssold	84200000	usd
CY2023Q1	fbiz	Loans And Leases Transferred To Third Parties Total Principal Amount LoansAndLeasesTransferredToThirdPartiesTotalPrincipalAmount	22600000	usd
CY2024Q1	fbiz	Gain Loss Recognizedon Participation Interestin Originated Loans GainLossRecognizedonParticipationInterestinOriginatedLoans	0	usd
CY2024Q1	fbiz	Total Amount Of Outstanding Loans Transferred To Third Parties As Loan Participations TotalAmountOfOutstandingLoansTransferredToThirdPartiesAsLoanParticipations	302800000	usd
CY2023Q4	fbiz	Total Amount Of Outstanding Loans Transferred To Third Parties As Loan Participations TotalAmountOfOutstandingLoansTransferredToThirdPartiesAsLoanParticipations	279500000	usd
CY2024Q1	fbiz	Total Amount Of Loan Participations Remaining On Corporations Balance Sheet TotalAmountOfLoanParticipationsRemainingOnCorporationsBalanceSheet	376800000	usd
CY2023Q4	fbiz	Total Amount Of Loan Participations Remaining On Corporations Balance Sheet TotalAmountOfLoanParticipationsRemainingOnCorporationsBalanceSheet	367400000	usd
CY2023Q4	fbiz	Loans In The Participation Sold Portfolio Considered Impaired Gross Amount LoansInTheParticipationSoldPortfolioConsideredImpairedGrossAmount	0	usd
CY2024Q1	fbiz	Loans In The Participation Sold Portfolio Considered Impaired Gross Amount LoansInTheParticipationSoldPortfolioConsideredImpairedGrossAmount	0	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	123574000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	571109000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	394703000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	285906000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	295137000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	721454000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	518707000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	2910590000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	568931000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	423678000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	296979000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	304487000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	158267000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	586727000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	510949000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	2850018000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Before Fees Gross LoansAndLeasesReceivableBeforeFeesGross	2910590000	usd
CY2024Q1	fbiz	Financing Receivable Recorded Investment30 To59 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestment30To59DaysPastDuePercentOfPortfolio	0.0007
CY2024Q1	fbiz	Financing Receivable Recorded Investment60 To89 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestment60To89DaysPastDuePercentOfPortfolio	0.0002
CY2024Q1	fbiz	Financing Receivable Recorded Investment Equal To Greater Than90 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDuePercentOfPortfolio	0.0057
CY2024Q1	fbiz	Financing Receivable Recorded Investment Past Due Percent Of Portfolio FinancingReceivableRecordedInvestmentPastDuePercentOfPortfolio	0.0066
CY2024Q1	fbiz	Financing Receivable Recorded Investment Current Percent Of Portfolio FinancingReceivableRecordedInvestmentCurrentPercentOfPortfolio	0.9934
CY2024Q1	fbiz	Financing Receivable Recorded Investment Gross Percent Of Portfolio FinancingReceivableRecordedInvestmentGrossPercentOfPortfolio	1.0000
CY2023Q4	us-gaap	Loans And Leases Receivable Before Fees Gross LoansAndLeasesReceivableBeforeFeesGross	2850018000	usd
CY2023Q4	fbiz	Financing Receivable Recorded Investment30 To59 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestment30To59DaysPastDuePercentOfPortfolio	0.0012
CY2023Q4	fbiz	Financing Receivable Recorded Investment60 To89 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestment60To89DaysPastDuePercentOfPortfolio	0.0004
CY2023Q4	fbiz	Financing Receivable Recorded Investment Equal To Greater Than90 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDuePercentOfPortfolio	0.0064
CY2023Q4	fbiz	Financing Receivable Recorded Investment Past Due Percent Of Portfolio FinancingReceivableRecordedInvestmentPastDuePercentOfPortfolio	0.0080
CY2023Q4	fbiz	Financing Receivable Recorded Investment Current Percent Of Portfolio FinancingReceivableRecordedInvestmentCurrentPercentOfPortfolio	0.9920
CY2023Q4	fbiz	Financing Receivable Recorded Investment Gross Percent Of Portfolio FinancingReceivableRecordedInvestmentGrossPercentOfPortfolio	1.0000
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	9325000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	10504000	usd
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	0	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	9690000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	10907000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	0	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Ratio Of Nonperforming Loans To All Loans LoansAndLeasesReceivableRatioOfNonperformingLoansToAllLoans	0.0068
CY2023Q4	us-gaap	Loans And Leases Receivable Ratio Of Nonperforming Loans To All Loans LoansAndLeasesReceivableRatioOfNonperformingLoansToAllLoans	0.0072
CY2024Q1	fbiz	Ratio Of Allowance For Loan And Lease Losses To Total Gross Loans And Leases RatioOfAllowanceForLoanAndLeaseLossesToTotalGrossLoansAndLeases	0.0119
CY2023Q4	fbiz	Ratio Of Allowance For Loan And Lease Losses To Total Gross Loans And Leases RatioOfAllowanceForLoanAndLeaseLossesToTotalGrossLoansAndLeases	0.0116
CY2024Q1	fbiz	Ratio Of Allowance For Loan And Leases Losses To Non Accrual Loans And Leases RatioOfAllowanceForLoanAndLeasesLossesToNonAccrualLoansAndLeases	1.7464
CY2023Q4	fbiz	Ratio Of Allowance For Loan And Leases Losses To Non Accrual Loans And Leases RatioOfAllowanceForLoanAndLeasesLossesToNonAccrualLoansAndLeases	1.6021
CY2024Q1	fbiz	Impaired Financing Receivable Amortized Cost ImpairedFinancingReceivableAmortizedCost	13563000	usd
CY2023Q4	fbiz	Impaired Financing Receivable Amortized Cost ImpairedFinancingReceivableAmortizedCost	14291000	usd
CY2024Q1	fbiz	Financing Receivable Nonaccrual Modifications Number Of Contracts FinancingReceivableNonaccrualModificationsNumberOfContracts	2	securities
CY2023Q1	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	0	loans
CY2024Q1	fbiz	Financing Receivable Modifications Subsequent Default Number Of Contracts FinancingReceivableModificationsSubsequentDefaultNumberOfContracts	1	loans
CY2024Q1	us-gaap	Financing Receivable Excluding Accrued Interest Modified Subsequent Default FinancingReceivableExcludingAccruedInterestModifiedSubsequentDefault	283000	usd
CY2023Q1	fbiz	Financing Receivable Modifications Subsequent Default Number Of Contracts FinancingReceivableModificationsSubsequentDefaultNumberOfContracts	0	loans
CY2024Q1	fbiz	Unfunded Commitments Troubled Debt Restructurings UnfundedCommitmentsTroubledDebtRestructurings	0	usd
CY2023Q4	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	32997000	usd
CY2024Q1	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	921000	usd
CY2024Q1	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	227000	usd
CY2024Q1	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	-694000	usd
CY2024Q1	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	2326000	usd
CY2024Q1	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	34629000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	32799000	usd
CY2024Q1	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	1830000	usd
CY2024Q1	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	34629000	usd
CY2022Q4	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	24230000	usd
CY2023Q1	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	166000	usd
CY2023Q1	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	107000	usd
CY2023Q1	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	-59000	usd
CY2023Q1	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	1561000	usd
CY2023Q1	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	27550000	usd
CY2023Q1	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	26140000	usd
CY2023Q1	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	1410000	usd
CY2023Q1	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	27550000	usd
CY2024Q1	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	26181000	usd
CY2024Q1	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	6618000	usd
CY2024Q1	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	32799000	usd
CY2024Q1	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	2890761000	usd
CY2024Q1	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	19829000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	2910590000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	25286000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	5989000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	31275000	usd
CY2023Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	2829421000	usd
CY2023Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	20597000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	2850018000	usd
CY2024Q1	us-gaap	Operating Lease Cost OperatingLeaseCost	357000	usd
CY2023Q1	us-gaap	Operating Lease Cost OperatingLeaseCost	382000	usd
CY2024Q1	us-gaap	Short Term Lease Cost ShortTermLeaseCost	37000	usd
CY2023Q1	us-gaap	Short Term Lease Cost ShortTermLeaseCost	63000	usd
CY2024Q1	us-gaap	Variable Lease Cost VariableLeaseCost	141000	usd
CY2023Q1	us-gaap	Variable Lease Cost VariableLeaseCost	150000	usd
CY2024Q1	us-gaap	Sublease Income SubleaseIncome	0	usd
CY2023Q1	us-gaap	Sublease Income SubleaseIncome	45000	usd
CY2024Q1	us-gaap	Lease Cost LeaseCost	535000	usd
CY2023Q1	us-gaap	Lease Cost LeaseCost	550000	usd
CY2024Q1	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y6M18D
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y8M12D
CY2024Q1	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0366
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0361
CY2024Q1	us-gaap	Lessee Operating Lease Liability Payments Remainder Of Fiscal Year LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear	1139000	usd
CY2024Q1	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	1408000	usd
CY2024Q1	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	1400000	usd
CY2024Q1	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	1427000	usd
CY2024Q1	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	1113000	usd
CY2024Q1	fbiz	Lessee Operating Lease Liability To Be Paid After Year Four LesseeOperatingLeaseLiabilityToBePaidAfterYearFour	3600000	usd
CY2024Q1	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	10087000	usd
CY2024Q1	fbiz	Discountonoperatingleasecashflows Discountonoperatingleasecashflows	1423000	usd
CY2024Q1	us-gaap	Operating Lease Liability OperatingLeaseLiability	8664000	usd
CY2024Q1	us-gaap	Interest Receivable InterestReceivable	13650000	usd
CY2023Q4	us-gaap	Interest Receivable InterestReceivable	13275000	usd
CY2024Q1	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	8267000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	9508000	usd
CY2024Q1	fbiz	Investmentin Historic Development Entities InvestmentinHistoricDevelopmentEntities	2393000	usd
CY2023Q4	fbiz	Investmentin Historic Development Entities InvestmentinHistoricDevelopmentEntities	2393000	usd
CY2024Q1	fbiz	Investment In Low Income Housing Development Entities InvestmentInLowIncomeHousingDevelopmentEntities	31471000	usd
CY2023Q4	fbiz	Investment In Low Income Housing Development Entities InvestmentInLowIncomeHousingDevelopmentEntities	33303000	usd
CY2024Q1	fbiz	Investmentin Limited Partnerships InvestmentinLimitedPartnerships	15566000	usd
CY2023Q4	fbiz	Investmentin Limited Partnerships InvestmentinLimitedPartnerships	15027000	usd
CY2024Q1	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	5309000	usd
CY2023Q4	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	4269000	usd
CY2024Q1	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	13688000	usd
CY2023Q4	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	13283000	usd
CY2024Q1	us-gaap	Other Assets OtherAssets	90344000	usd
CY2023Q4	us-gaap	Other Assets OtherAssets	91058000	usd
CY2024Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1300000	usd
CY2023Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	436000	usd
CY2024Q1	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	1700000	usd
CY2023Q1	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	586000	usd
CY2024Q1	us-gaap	Deposits Deposits	2755406000	usd
CY2024Q1	fbiz	Average Balance Deposits AverageBalanceDeposits	2803989000	usd
CY2024Q1	fbiz	Deposits Weighted Average Interest Rate Duringthe Period DepositsWeightedAverageInterestRateDuringthePeriod	0.0340
CY2023Q4	us-gaap	Deposits Deposits	2796779000	usd
CY2023	fbiz	Average Balance Deposits AverageBalanceDeposits	2444438000	usd
CY2023	fbiz	Deposits Weighted Average Interest Rate Duringthe Period DepositsWeightedAverageInterestRateDuringthePeriod	0.0292
CY2024Q1	us-gaap	Time Deposit Maturities Remainder Of Fiscal Year TimeDepositMaturitiesRemainderOfFiscalYear	494093000	usd
CY2024Q1	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	40573000	usd
CY2024Q1	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	50383000	usd
CY2024Q1	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	73650000	usd
CY2024Q1	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	12821000	usd
CY2024Q1	fbiz	Time Deposit Maturities After Year Four TimeDepositMaturitiesAfterYearFour	2072000	usd
CY2024Q1	us-gaap	Time Deposits TimeDeposits	673592000	usd
CY2024Q1	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	381718000	usd
CY2024Q1	fbiz	Borrowed Funds Average Balance BorrowedFundsAverageBalance	336765000	usd
CY2024Q1	us-gaap	Debt Instrument Interest Rate During Period DebtInstrumentInterestRateDuringPeriod	0.0289
CY2023Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	330916000	usd
CY2023	fbiz	Borrowed Funds Average Balance BorrowedFundsAverageBalance	390881000	usd
CY2023	us-gaap	Debt Instrument Interest Rate During Period DebtInstrumentInterestRateDuringPeriod	0.0279
CY2024Q1	us-gaap	Long Term Debt Maturities Repayments Of Principal Remainder Of Fiscal Year LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear	160810000	usd
CY2024Q1	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	48000000	usd
CY2024Q1	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	65000000	usd
CY2024Q1	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	28000000	usd
CY2024Q1	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	10450000	usd
CY2024Q1	fbiz	Long Term Debt Maturity After Year Four LongTermDebtMaturityAfterYearFour	69458000	usd
CY2024Q1	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	381718000	usd
CY2022Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	12500	shares
CY2022Q4	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding	12500000	usd
CY2022	us-gaap	Preferred Stock Dividend Rate Percentage PreferredStockDividendRatePercentage	0.070
CY2022Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2022Q4	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	1000
CY2022	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	12000000	usd
CY2022	us-gaap	Preferred Stock Dividend Rate Percentage PreferredStockDividendRatePercentage	0.070
CY2024Q1	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	219000	usd
CY2024Q1	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	1000
CY2024Q1	us-gaap	Contractual Obligation ContractualObligation	3400000	usd
CY2024Q1	fbiz	Sba Loans Probabilityof Future Losses SBALoansProbabilityofFutureLosses	1100000	usd
CY2023Q4	fbiz	Sba Recourse Reserve SBARecourseReserve	955000	usd
CY2022Q4	fbiz	Sba Recourse Reserve SBARecourseReserve	441000	usd
CY2024Q1	fbiz	Sba Recourse Provision Benefit SBARecourseProvisionBenefit	126000	usd
CY2023Q1	fbiz	Sba Recourse Provision Benefit SBARecourseProvisionBenefit	-18000	usd
CY2024Q1	fbiz	Sba Recourse Reserve SBARecourseReserve	1081000	usd
CY2023Q1	fbiz	Sba Recourse Reserve SBARecourseReserve	423000	usd
CY2024Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	usd
CY2024Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3	0	usd
CY2024Q1	fbiz	Fair Value Liabilities Level1to Level2 Transfers Amount1 FairValueLiabilitiesLevel1toLevel2TransfersAmount1	0	usd
CY2024Q1	fbiz	Fair Value Assets Level1to Level2 Transfers Amount1 FairValueAssetsLevel1toLevel2TransfersAmount1	0	usd
CY2023	fbiz	Fair Value Liabilities Level1to Level2 Transfers Amount1 FairValueLiabilitiesLevel1toLevel2TransfersAmount1	0	usd
CY2024Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	usd
CY2024Q1	fbiz	Fair Value Assets Level2to Level1 Transfers Amount1 FairValueAssetsLevel2toLevel1TransfersAmount1	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	0	usd
CY2024Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	usd
CY2023	fbiz	Fair Value Assets Level2to Level1 Transfers Amount1 FairValueAssetsLevel2toLevel1TransfersAmount1	0	usd
CY2023	fbiz	Fair Value Liabilities Level2to Level1 Transfers Amount1 FairValueLiabilitiesLevel2toLevel1TransfersAmount1	0	usd
CY2023	fbiz	Fair Value Assets Level1to Level2 Transfers Amount1 FairValueAssetsLevel1toLevel2TransfersAmount1	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	usd
CY2024Q1	fbiz	Fair Value Liabilities Level2to Level1 Transfers Amount1 FairValueLiabilitiesLevel2toLevel1TransfersAmount1	0	usd
CY2024Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	72040000	usd
CY2024Q1	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	72040000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	314114000	usd
CY2024Q1	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	314114000	usd
CY2024Q1	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	8131000	usd
CY2024Q1	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	7848000	usd
CY2024Q1	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	4855000	usd
CY2024Q1	us-gaap	Loans Held For Sale Fair Value Disclosure LoansHeldForSaleFairValueDisclosure	5244000	usd
CY2024Q1	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2878065000	usd
CY2024Q1	us-gaap	Loans Receivable Fair Value Disclosure LoansReceivableFairValueDisclosure	2848940000	usd
CY2024Q1	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	13326000	usd
CY2024Q1	us-gaap	Interest Receivable InterestReceivable	13650000	usd
CY2024Q1	fbiz	Accrued Interest Receivable Fair Value Disclosure AccruedInterestReceivableFairValueDisclosure	13650000	usd
CY2024Q1	us-gaap	Deposits Deposits	2755406000	usd
CY2024Q1	us-gaap	Deposits Fair Value Disclosure DepositsFairValueDisclosure	2754078000	usd
CY2024Q1	fbiz	Federal Home Loan Bank And Other Borrowings FederalHomeLoanBankAndOtherBorrowings	381718000	usd
CY2024Q1	fbiz	Federal Home Loan Bank And Other Borrowings Fair Value Disclosure FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure	370486000	usd
CY2024Q1	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	10809000	usd
CY2024Q1	us-gaap	Accrued Liabilities Fair Value Disclosure AccruedLiabilitiesFairValueDisclosure	10809000	usd
CY2024Q1	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	162000	usd
CY2024Q1	fbiz	Standby Letters Of Credit Fair Value Disclosure StandbyLettersOfCreditFairValueDisclosure	162000	usd
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	139510000	usd
CY2023Q4	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	139510000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	297006000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	297006000	usd
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	8503000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	8255000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	4589000	usd
CY2023Q4	us-gaap	Loans Held For Sale Fair Value Disclosure LoansHeldForSaleFairValueDisclosure	4956000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2818986000	usd
CY2023Q4	us-gaap	Loans Receivable Fair Value Disclosure LoansReceivableFairValueDisclosure	2789731000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	12042000	usd
CY2023Q4	us-gaap	Interest Receivable InterestReceivable	13275000	usd
CY2023Q4	fbiz	Accrued Interest Receivable Fair Value Disclosure AccruedInterestReceivableFairValueDisclosure	13275000	usd
CY2023Q4	us-gaap	Deposits Deposits	2796779000	usd
CY2023Q4	us-gaap	Deposits Fair Value Disclosure DepositsFairValueDisclosure	2795463000	usd
CY2023Q4	fbiz	Federal Home Loan Bank And Other Borrowings FederalHomeLoanBankAndOtherBorrowings	330916000	usd
CY2023Q4	fbiz	Federal Home Loan Bank And Other Borrowings Fair Value Disclosure FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure	320287000	usd
CY2023Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	10860000	usd
CY2023Q4	us-gaap	Accrued Liabilities Fair Value Disclosure AccruedLiabilitiesFairValueDisclosure	10860000	usd
CY2023Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	190000	usd
CY2023Q4	fbiz	Standby Letters Of Credit Fair Value Disclosure StandbyLettersOfCreditFairValueDisclosure	190000	usd
CY2024Q1	fbiz	Accumulated Derivative Credit Valuation Adjustment AccumulatedDerivativeCreditValuationAdjustment	117000	usd
CY2023Q4	fbiz	Accumulated Derivative Credit Valuation Adjustment AccumulatedDerivativeCreditValuationAdjustment	117000	usd
CY2024Q1	us-gaap	Description Of Material Affects Of Noncompliance DescriptionOfMaterialAffectsOfNoncompliance	Failure to meet minimum capital requirements can result in certain mandatory, and possibly additional discretionary actions on the part of regulators, that if undertaken, could have a direct material effect on the Bank’s assets, liabilities, and certain off-balance sheet items as calculated under regulatory practices.
CY2024Q1	us-gaap	Capital Capital	384083000	usd
CY2024Q1	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1136
CY2024Q1	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	270485000	usd
CY2024Q1	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0800
CY2024Q1	fbiz	Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer CapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	355011000	usd
CY2024Q1	fbiz	Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets CapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.1050
CY2024Q1	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	299707000	usd
CY2024Q1	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.0886
CY2024Q1	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	202864000	usd
CY2024Q1	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0600
CY2024Q1	fbiz	Tier One Risk Based Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer TierOneRiskBasedCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	287390000	usd
CY2024Q1	fbiz	Tier One Risk Based Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets TierOneRiskBasedCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0850
CY2024Q1	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	287715000	usd
CY2024Q1	fbiz	Common Equity Tier One Capitalto Risk Weighted Assets CommonEquityTierOneCapitaltoRiskWeightedAssets	0.0851
CY2024Q1	us-gaap	Common Equity Tier One Capital Required For Capital Adequacy CommonEquityTierOneCapitalRequiredForCapitalAdequacy	152148000	usd
CY2024Q1	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacyto Risk Weighted Assets CommonEquityTierOneCapitalRequiredforCapitalAdequacytoRiskWeightedAssets	0.0450
CY2024Q1	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer CommonEquityTierOneCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	236674000	usd
CY2024Q1	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets CommonEquityTierOneCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0700
CY2024Q1	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	299707000	usd
CY2024Q1	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.0845
CY2024Q1	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	141847000	usd
CY2024Q1	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2024Q1	fbiz	Tier One Leverage Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer TierOneLeverageCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	141847000	usd
CY2024Q1	fbiz	Tier One Leverage Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets TierOneLeverageCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0400
CY2023Q4	us-gaap	Capital Capital	375440000	usd
CY2023Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1119
CY2023Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	268500000	usd
CY2023Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0800
CY2023Q4	fbiz	Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer CapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	352406000	usd
CY2023Q4	fbiz	Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets CapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.1050
CY2023Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	293338000	usd
CY2023Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.0874
CY2023Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	201375000	usd
CY2023Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0600
CY2023Q4	fbiz	Tier One Risk Based Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer TierOneRiskBasedCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	285281000	usd
CY2023Q4	fbiz	Tier One Risk Based Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets TierOneRiskBasedCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0850
CY2023Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	281346000	usd
CY2023Q4	fbiz	Common Equity Tier One Capitalto Risk Weighted Assets CommonEquityTierOneCapitaltoRiskWeightedAssets	0.0838
CY2023Q4	us-gaap	Common Equity Tier One Capital Required For Capital Adequacy CommonEquityTierOneCapitalRequiredForCapitalAdequacy	151031000	usd
CY2023Q4	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacyto Risk Weighted Assets CommonEquityTierOneCapitalRequiredforCapitalAdequacytoRiskWeightedAssets	0.0450
CY2023Q4	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer CommonEquityTierOneCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	234937000	usd
CY2023Q4	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets CommonEquityTierOneCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0700
CY2023Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	293338000	usd
CY2023Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.0843
CY2023Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	139145000	usd
CY2023Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2023Q4	fbiz	Tier One Leverage Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer TierOneLeverageCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	139145000	usd
CY2023Q4	fbiz	Tier One Leverage Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets TierOneLeverageCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0400

Files In Submission

Name	View Source	Status
0001521951-24-000033-index-headers.html	Edgar Link	pending
0001521951-24-000033-index.html	Edgar Link	pending
0001521951-24-000033.txt	Edgar Link	pending
0001521951-24-000033-xbrl.zip	Edgar Link	pending
fbiz-20240331.htm	Edgar Link	pending
fbiz-20240331.xsd	Edgar Link	pending
fbiz20240331exhibit311.htm	Edgar Link	pending
fbiz20240331exhibit312.htm	Edgar Link	pending
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Financial_Report.xlsx	Edgar Link	pending
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fbiz-20240331_cal.xml	Edgar Link	unprocessable
fbiz-20240331_def.xml	Edgar Link	unprocessable
fbiz-20240331_pre.xml	Edgar Link	unprocessable
FilingSummary.xml	Edgar Link	unprocessable
fbiz-20240331_htm.xml	Edgar Link	completed
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report.css	Edgar Link	pending
Show.js	Edgar Link	pending
fbiz-20240331_lab.xml	Edgar Link	unprocessable

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FIRST BUSINESS FINANCIAL SERVICES, INC. Stock $fbiz

2024 Q2 Form 10-Q Financial Statement

#000152195124000033 Filed on April 26, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$FBIZ FIRST BUSINESS FINANCIAL SERVICES, INC. Stock $fbiz

2024 Q2 Form 10-Q Financial Statement

#000152195124000033 Filed on April 26, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$FBIZ
FIRST BUSINESS FINANCIAL SERVICES, INC. Stock $fbiz