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

$fbiz Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000152195124000020 Filed on February 28, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$55.78M	$54.76M	$194.9M
YoY Change	32.61%	42.91%	60.61%
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	$791.0K	$796.0K	$961.0K
YoY Change	-13.27%	-18.61%	66.26%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$26.27M	$25.22M	$82.34M
YoY Change	71.05%	132.1%	258.8%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$10.60M	$12.47M	$47.14M
YoY Change	-10.07%	-0.66%	-9.77%
Income Tax	$1.752M	$2.703M	$10.11M
% Of Pretax Income	16.53%	21.67%	21.45%
Net Earnings	$8.415M	$9.551M	$36.15M
YoY Change	-6.28%	-5.96%	-11.52%
Net Earnings / Revenue	15.09%	17.44%	18.55%
Basic Earnings Per Share	$1.04	$1.15	$4.33
Diluted Earnings Per Share	$1.04	$1.18	$4.45
COMMON SHARES
Basic Shares Outstanding	8.307M shares	8.315M shares	8.131M shares
Diluted Shares Outstanding	8.125M shares		8.131M shares

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$72.04M	$139.5M
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	$12.57M	$12.75M	$12.75M
YoY Change	154.71%	193.76%	5.98%
Goodwill		$10.70M
YoY Change		0.0%
Intangibles
YoY Change
Long-Term Investments	$49.43M	$50.72M	$50.72M
YoY Change	48.63%	73.18%	73.18%
Other Assets	$8.267M	$9.508M	$9.508M
YoY Change	-27.85%	-18.81%	-18.81%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$3.531B	$3.508B	$3.508B
YoY Change	11.6%	17.85%	17.85%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$26.65M	$29.66M	$29.66M
YoY Change	31.3%	53.18%	53.18%
Accrued Expenses	$8.664M	$8.954M	$8.954M
YoY Change	-11.79%	-12.0%	-12.0%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$35.31M	$38.61M	$38.61M
YoY Change	17.24%	30.73%	30.73%
LONG-TERM LIABILITIES
Long-Term Debt	$49.47M	$330.9M	$330.9M
YoY Change	43.97%	718.53%	718.53%
Other Long-Term Liabilities	$61.13M	$51.95M	$51.95M
YoY Change	24.73%	-15.42%	-15.42%
Total Long-Term Liabilities	$110.6M	$382.9M	$382.9M
YoY Change	32.66%	275.92%	275.92%
TOTAL LIABILITIES
Total Short-Term Liabilities	$35.31M	$38.61M	$38.61M
Total Long-Term Liabilities	$110.6M	$382.9M	$382.9M
Total Liabilities	$3.234B	$3.218B	$3.218B
YoY Change	11.59%	18.49%	18.49%
SHAREHOLDERS EQUITY
Retained Earnings	$237.3M	$230.7M
YoY Change	13.52%	13.38%
Common Stock	$91.41M	$90.71M
YoY Change	3.56%	3.54%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$30.71M	$30.13M
YoY Change	5.82%	10.94%
Treasury Stock Shares
Shareholders Equity	$297.8M	$289.6M	$289.6M
YoY Change
Total Liabilities & Shareholders Equity	$3.531B	$3.508B	$3.508B
YoY Change	11.6%	17.85%	17.85%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	$8.415M	$9.551M	$36.15M
YoY Change	-6.28%	-5.96%	-11.52%
Depreciation, Depletion And Amortization	$791.0K	$796.0K	$961.0K
YoY Change	-13.27%	-18.61%	66.26%
Cash From Operating Activities	$8.683M	$13.33M	$52.29M
YoY Change	-12.37%	83.76%	35.31%
INVESTING ACTIVITIES
Capital Expenditures	$397.0K	$314.0K	$2.884M
YoY Change	-50.25%	-77.18%	-10.52%
Acquisitions
YoY Change
Other Investing Activities	-$82.33M	-$111.1M	-$504.0M
YoY Change	-28.75%	-12.39%	108.21%
Cash From Investing Activities	-$82.73M	-$111.4M	-$506.8M
YoY Change	-28.89%	-13.09%	106.65%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	6.575M	104.7M	$491.4M
YoY Change	-96.53%	-7.08%	94.84%
NET CHANGE
Cash From Operating Activities	8.683M	13.33M	$52.29M
Cash From Investing Activities	-82.73M	-111.4M	-$506.8M
Cash From Financing Activities	6.575M	104.7M	$491.4M
Net Change In Cash	-67.47M	6.598M	$36.83M
YoY Change	-181.01%	-179.66%	-19.19%
FREE CASH FLOW
Cash From Operating Activities	$8.683M	$13.33M	$52.29M
Capital Expenditures	$397.0K	$314.0K	$2.884M
Free Cash Flow	$8.286M	$13.02M	$49.41M
YoY Change	-9.05%	121.43%	39.48%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2023	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	4075000	usd
CY2022	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	121371000	usd
CY2021	us-gaap	Interest Expense Deposits InterestExpenseDeposits	3553000	usd
CY2023	us-gaap	Interest Expense Deposits InterestExpenseDeposits	71418000	usd
CY2023	fbiz	Interest Expense Federal Home Loan Bank And Other Borrowings InterestExpenseFederalHomeLoanBankAndOtherBorrowings	10922000	usd
CY2022	fbiz	Interest Expense Federal Home Loan Bank And Other Borrowings InterestExpenseFederalHomeLoanBankAndOtherBorrowings	9267000	usd
CY2021	fbiz	Interest Expense Federal Home Loan Bank And Other Borrowings InterestExpenseFederalHomeLoanBankAndOtherBorrowings	6667000	usd
CY2023	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	0	usd
CY2022	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	504000	usd
CY2021	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	1113000	usd
CY2022	us-gaap	Interest Expense InterestExpense	22949000	usd
CY2021	us-gaap	Interest Expense InterestExpense	11333000	usd
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	84662000	usd
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
CY2023	dei	Entity Central Index Key EntityCentralIndexKey	0001521951
CY2023	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
CY2023	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2023	dei	Amendment Flag AmendmentFlag	false
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	001-34095
CY2023	dei	Entity Registrant Name EntityRegistrantName	FIRST BUSINESS FINANCIAL SERVICES, INC.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	WI
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	39-1576570
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	401 Charmany Drive
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	53719
CY2023	dei	City Area Code CityAreaCode	608
CY2023	dei	Local Phone Number LocalPhoneNumber	238-8008
CY2023	dei	Security12b Title Security12bTitle	Common Stock, $0.01 par value
CY2023	dei	Trading Symbol TradingSymbol	FBIZ
CY2023	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	No
CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2023	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2023	dei	Entity Filer Category EntityFilerCategory	Accelerated Filer
CY2023	dei	Entity Small Business EntitySmallBusiness	true
CY2023	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2023	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2023	dei	Document Fin Stmt Error Correction Flag DocumentFinStmtErrorCorrectionFlag	false
CY2023	dei	Entity Shell Company EntityShellCompany	false
CY2023Q2	dei	Entity Public Float EntityPublicFloat	245200000	usd
CY2024Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	8306543	shares
CY2023	dei	Auditor Firm AuditorFirmId	173
CY2023Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	32348000	usd
CY2022Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	25811000	usd
CY2023Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	107162000	usd
CY2022Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	76871000	usd
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	139510000	usd
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	102682000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	297006000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	212024000	usd
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	8503000	usd
CY2022Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	12635000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	4589000	usd
CY2022Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	2632000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	31275000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	24230000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2818986000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2418836000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	6190000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	4340000	usd
CY2023Q4	us-gaap	Foreclosed Assets ForeclosedAssets	247000	usd
CY2022Q4	us-gaap	Foreclosed Assets ForeclosedAssets	95000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	6559000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	7690000	usd
CY2023Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	55536000	usd
CY2022Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	54018000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	12042000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	17812000	usd
CY2023Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	12023000	usd
CY2022Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	12159000	usd
CY2023Q4	us-gaap	Derivative Assets DerivativeAssets	55597000	usd
CY2022Q4	us-gaap	Derivative Assets DerivativeAssets	68581000	usd
CY2023Q4	us-gaap	Other Assets OtherAssets	91058000	usd
CY2022Q4	us-gaap	Other Assets OtherAssets	63107000	usd
CY2023Q4	us-gaap	Assets Assets	3507846000	usd
CY2022Q4	us-gaap	Assets Assets	2976611000	usd
CY2023Q4	us-gaap	Deposits Deposits	2796779000	usd
CY2022Q4	us-gaap	Deposits Deposits	2168206000	usd
CY2023Q4	fbiz	Federal Home Loan Bank And Other Borrowings FederalHomeLoanBankAndOtherBorrowings	330916000	usd
CY2022Q4	fbiz	Federal Home Loan Bank And Other Borrowings FederalHomeLoanBankAndOtherBorrowings	456808000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	8954000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	10175000	usd
CY2023Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	51949000	usd
CY2022Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	61419000	usd
CY2023Q4	us-gaap	Other Liabilities OtherLiabilities	29660000	usd
CY2022Q4	us-gaap	Other Liabilities OtherLiabilities	19363000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	3218258000	usd
CY2022Q4	us-gaap	Liabilities Liabilities	2715971000	usd
CY2022Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2023Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2023Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2500000	shares
CY2022Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2500000	shares
CY2022Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	12500	shares
CY2023Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	12500	shares
CY2022Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	12500	shares
CY2023Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	12500	shares
CY2022	us-gaap	Preferred Stock Dividend Rate Percentage PreferredStockDividendRatePercentage	0.07
CY2023Q4	us-gaap	Preferred Stock Value PreferredStockValue	11992000	usd
CY2022Q4	us-gaap	Preferred Stock Value PreferredStockValue	11992000	usd
CY2023Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2022Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	25000000	shares
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	25000000	shares
CY2023Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	9418463	shares
CY2022Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	9371078	shares
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	8314778	shares
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	8362085	shares
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	95000	usd
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	94000	usd
CY2023Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	90616000	usd
CY2022Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	87512000	usd
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	230728000	usd
CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	203507000	usd
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-13717000	usd
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-15310000	usd
CY2023Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	1103685	shares
CY2022Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	1008993	shares
CY2023Q4	us-gaap	Treasury Stock Value TreasuryStockValue	30126000	usd
CY2022Q4	us-gaap	Treasury Stock Value TreasuryStockValue	27155000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	289588000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	260640000	usd
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	3507846000	usd
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2976611000	usd
CY2023	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	182650000	usd
CY2022	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	115368000	usd
CY2021	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	91844000	usd
CY2023	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	8203000	usd
CY2022	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	4472000	usd
CY2021	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	3410000	usd
CY2022	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	1531000	usd
CY2021	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	741000	usd
CY2023	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	194928000	usd
CY2021	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	95995000	usd
CY2022	us-gaap	Interest Expense Deposits InterestExpenseDeposits	13178000	usd
CY2023	us-gaap	Interest Expense InterestExpense	82340000	usd
CY2023	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	112588000	usd
CY2022	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	98422000	usd
CY2023	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	8182000	usd
CY2022	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-3868000	usd
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-5803000	usd
CY2023	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	104406000	usd
CY2022	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	102290000	usd
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	90465000	usd
CY2023	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	11425000	usd
CY2022	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	10881000	usd
CY2021	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	10784000	usd
CY2023	us-gaap	Gain Loss On Sale Of Other Loans And Leases GainLossOnSaleOfOtherLoansAndLeases	2055000	usd
CY2022	us-gaap	Gain Loss On Sale Of Other Loans And Leases GainLossOnSaleOfOtherLoansAndLeases	2537000	usd
CY2021	us-gaap	Gain Loss On Sale Of Other Loans And Leases GainLossOnSaleOfOtherLoansAndLeases	4044000	usd
CY2023	fbiz	Revenuefrom Contractwith Customer Including Assessed Tax Service Chargeson Deposits RevenuefromContractwithCustomerIncludingAssessedTaxServiceChargesonDeposits	3131000	usd
CY2022	fbiz	Revenuefrom Contractwith Customer Including Assessed Tax Service Chargeson Deposits RevenuefromContractwithCustomerIncludingAssessedTaxServiceChargesonDeposits	3849000	usd
CY2021	fbiz	Revenuefrom Contractwith Customer Including Assessed Tax Service Chargeson Deposits RevenuefromContractwithCustomerIncludingAssessedTaxServiceChargesonDeposits	3837000	usd
CY2023	fbiz	Revenuefrom Contractwith Customer Including Assessed Tax Loan Fees RevenuefromContractwithCustomerIncludingAssessedTaxLoanFees	3363000	usd
CY2022	fbiz	Revenuefrom Contractwith Customer Including Assessed Tax Loan Fees RevenuefromContractwithCustomerIncludingAssessedTaxLoanFees	3010000	usd
CY2021	fbiz	Revenuefrom Contractwith Customer Including Assessed Tax Loan Fees RevenuefromContractwithCustomerIncludingAssessedTaxLoanFees	2506000	usd
CY2023	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	875000	usd
CY2022	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	683000	usd
CY2021	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	0	usd
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	36152000	usd
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	40175000	usd
CY2023	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1494000	usd
CY2022	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	2227000	usd
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1413000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-45000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	0	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	29000	usd
CY2023	fbiz	Swap Fee Income SwapFeeIncome	2964000	usd
CY2022	fbiz	Swap Fee Income SwapFeeIncome	1793000	usd
CY2021	fbiz	Swap Fee Income SwapFeeIncome	1368000	usd
CY2023	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	6921000	usd
CY2022	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	5131000	usd
CY2021	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	4119000	usd
CY2023	us-gaap	Noninterest Income NoninterestIncome	31308000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	29428000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	28100000	usd
CY2023	us-gaap	Labor And Related Expense LaborAndRelatedExpense	61059000	usd
CY2022	us-gaap	Labor And Related Expense LaborAndRelatedExpense	57742000	usd
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	51710000	usd
CY2023	us-gaap	Occupancy Net OccupancyNet	2381000	usd
CY2022	us-gaap	Occupancy Net OccupancyNet	2358000	usd
CY2021	us-gaap	Occupancy Net OccupancyNet	2180000	usd
CY2023	fbiz	Professional Fees Expense ProfessionalFeesExpense	5325000	usd
CY2022	fbiz	Professional Fees Expense ProfessionalFeesExpense	4881000	usd
CY2021	fbiz	Professional Fees Expense ProfessionalFeesExpense	3736000	usd
CY2023	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	3826000	usd
CY2022	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	3197000	usd
CY2021	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	3087000	usd
CY2023	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	2889000	usd
CY2022	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	2354000	usd
CY2021	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	2022000	usd
CY2023	us-gaap	Equipment Expense EquipmentExpense	1340000	usd
CY2022	us-gaap	Equipment Expense EquipmentExpense	1091000	usd
CY2021	us-gaap	Equipment Expense EquipmentExpense	990000	usd
CY2023	fbiz	Computer Software Expense ComputerSoftwareExpense	4985000	usd
CY2022	fbiz	Computer Software Expense ComputerSoftwareExpense	4416000	usd
CY2021	fbiz	Computer Software Expense ComputerSoftwareExpense	4260000	usd
CY2023	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	2238000	usd
CY2022	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1042000	usd
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1143000	usd
CY2023	us-gaap	Other Noninterest Expense OtherNoninterestExpense	4532000	usd
CY2022	us-gaap	Other Noninterest Expense OtherNoninterestExpense	2393000	usd
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	2407000	usd
CY2023	us-gaap	Noninterest Expense NoninterestExpense	88575000	usd
CY2022	us-gaap	Noninterest Expense NoninterestExpense	79474000	usd
CY2021	us-gaap	Noninterest Expense NoninterestExpense	71535000	usd
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	47139000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	52244000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	47030000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	10112000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11386000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11275000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	37027000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	40858000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	35755000	usd
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	35755000	usd
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.33
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.75
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.17
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.33
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.75
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.17
CY2023	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.91
CY2022	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.79
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.72
CY2023	us-gaap	Net Income Loss NetIncomeLoss	37027000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	40858000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	35755000	usd
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	5606000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-27730000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-4312000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-45000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	29000	usd
CY2023	fbiz	Other Comprehensive Income Loss Amortizationof Net Unrealized Losses Transferredto Heldto Maturityfrom Availablefor Salebeforetax OtherComprehensiveIncomeLossAmortizationofNetUnrealizedLossesTransferredtoHeldtoMaturityfromAvailableforSalebeforetax	4000	usd
CY2022	fbiz	Other Comprehensive Income Loss Amortizationof Net Unrealized Losses Transferredto Heldto Maturityfrom Availablefor Salebeforetax OtherComprehensiveIncomeLossAmortizationofNetUnrealizedLossesTransferredtoHeldtoMaturityfromAvailableforSalebeforetax	14000	usd
CY2021	fbiz	Other Comprehensive Income Loss Amortizationof Net Unrealized Losses Transferredto Heldto Maturityfrom Availablefor Salebeforetax OtherComprehensiveIncomeLossAmortizationofNetUnrealizedLossesTransferredtoHeldtoMaturityfromAvailableforSalebeforetax	26000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	-3514000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	9102000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	3610000	usd
CY2023	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	548000	usd
CY2022	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	-4761000	usd
CY2021	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	-181000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	1593000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13853000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-524000	usd
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	38620000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	27005000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	35231000	usd
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	206162000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	35755000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-524000	usd
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2513000	usd
CY2021	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	160000	usd
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.72
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	6166000	usd
CY2021	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	5478000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	232422000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	40858000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-13853000	usd
CY2022	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	11992000	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2584000	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	134000	usd
CY2022	us-gaap	Stock Issued During Period Value Treasury Stock Reissued StockIssuedDuringPeriodValueTreasuryStockReissued	0	usd
CY2022	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	683000	usd
CY2022	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	6688000	usd
CY2022	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	6126000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	260640000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	37027000	usd
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	1593000	usd
CY2023	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2977000	usd
CY2023	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	128000	usd
CY2023	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	875000	usd
CY2023	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	7578000	usd
CY2023	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	2971000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	289588000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	37027000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	40858000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	35755000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2120000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-775000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1223000	usd
CY2023	fbiz	Impairment Recovery Of Tax Credit Investments ImpairmentRecoveryOfTaxCreditInvestments	0	usd
CY2022	fbiz	Impairment Recovery Of Tax Credit Investments ImpairmentRecoveryOfTaxCreditInvestments	-351000	usd
CY2021	fbiz	Impairment Recovery Of Tax Credit Investments ImpairmentRecoveryOfTaxCreditInvestments	0	usd
CY2023	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	8182000	usd
CY2022	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-3868000	usd
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-5803000	usd
CY2023	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	3636000	usd
CY2022	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	4066000	usd
CY2021	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	3554000	usd
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	2977000	usd
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	2584000	usd
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	2513000	usd
CY2023	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-73000	usd
CY2022	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	0	usd
CY2021	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-78000	usd
CY2023	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	4053000	usd
CY2022	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	1035000	usd
CY2021	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	0	usd
CY2023	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1494000	usd
CY2022	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	2227000	usd
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1413000	usd
CY2023	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	149669000	usd
CY2022	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	124915000	usd
CY2021	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	99266000	usd
CY2023	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	149767000	usd
CY2022	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	128391000	usd
CY2021	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	108435000	usd
CY2023	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	2055000	usd
CY2022	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	2537000	usd
CY2021	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	4044000	usd
CY2023	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-13000	usd
CY2022	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	429000	usd
CY2021	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-15000	usd
CY2023	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	4922000	usd
CY2022	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	721000	usd
CY2021	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	371000	usd
CY2023	fbiz	Excess Tax Benefit Expense From Share Based Compensation Operating Activities ExcessTaxBenefitExpenseFromShareBasedCompensationOperatingActivities	-194000	usd
CY2022	fbiz	Excess Tax Benefit Expense From Share Based Compensation Operating Activities ExcessTaxBenefitExpenseFromShareBasedCompensationOperatingActivities	-264000	usd
CY2021	fbiz	Excess Tax Benefit Expense From Share Based Compensation Operating Activities ExcessTaxBenefitExpenseFromShareBasedCompensationOperatingActivities	-48000	usd
CY2023	us-gaap	Operating Lease Payments OperatingLeasePayments	1425000	usd
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	1470000	usd
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	1431000	usd
CY2023	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	21497000	usd
CY2022	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	7728000	usd
CY2021	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	6774000	usd
CY2023	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	15468000	usd
CY2022	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	5026000	usd
CY2021	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	2731000	usd
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	52292000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	38645000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	35992000	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	22114000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	40835000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	51166000	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	4115000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	7080000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	6586000	usd
CY2023	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	5085000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	usd
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	14955000	usd
CY2023	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	106967000	usd
CY2022	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	75740000	usd
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	93019000	usd
CY2023	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	25000	usd
CY2022	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	71000	usd
CY2021	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	0	usd
CY2023	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	408618000	usd
CY2022	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	199467000	usd
CY2021	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	86660000	usd
CY2023	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	1413000	usd
CY2022	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	1508000	usd
CY2021	us-gaap	Payments To Acquire Limited Partnership Interests PaymentsToAcquireLimitedPartnershipInterests	1059000	usd
CY2023	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	7000	usd
CY2022	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	17000	usd
CY2021	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	32000	usd
CY2023	fbiz	Investment In Tax Credit Investments InvestmentInTaxCreditInvestments	24160000	usd
CY2022	fbiz	Investment In Tax Credit Investments InvestmentInTaxCreditInvestments	11454000	usd
CY2021	fbiz	Investment In Tax Credit Investments InvestmentInTaxCreditInvestments	2964000	usd
CY2023	fbiz	Distribution From Tax Credit Investments DistributionFromTaxCreditInvestments	101000	usd
CY2022	fbiz	Distribution From Tax Credit Investments DistributionFromTaxCreditInvestments	474000	usd
CY2021	fbiz	Distribution From Tax Credit Investments DistributionFromTaxCreditInvestments	57000	usd
CY2023	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	32069000	usd
CY2022	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	45660000	usd
CY2021	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	7439000	usd
CY2023	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	37839000	usd
CY2022	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	41184000	usd
CY2021	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	7680000	usd
CY2023	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	2884000	usd
CY2022	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	3223000	usd
CY2021	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	391000	usd
CY2023	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	0	usd
CY2022	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	0	usd
CY2021	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	44000	usd
CY2023	fbiz	Premium Payment On Bank Owned Life Insurance Policies PremiumPaymentOnBankOwnedLifeInsurancePolicies	24000	usd
CY2022	fbiz	Premium Payment On Bank Owned Life Insurance Policies PremiumPaymentOnBankOwnedLifeInsurancePolicies	50000	usd
CY2021	fbiz	Premium Payment On Bank Owned Life Insurance Policies PremiumPaymentOnBankOwnedLifeInsurancePolicies	0	usd
CY2023	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	usd
CY2022	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	1859000	usd
CY2021	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	usd
CY2023	fbiz	Proceeds From Redemption Of Trust Ii Stock ProceedsFromRedemptionOfTrustIIStock	0	usd
CY2022	fbiz	Proceeds From Redemption Of Trust Ii Stock ProceedsFromRedemptionOfTrustIIStock	315000	usd
CY2021	fbiz	Proceeds From Redemption Of Trust Ii Stock ProceedsFromRedemptionOfTrustIIStock	0	usd
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-506849000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-245267000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-111012000	usd
CY2023	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	628573000	usd
CY2022	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	210283000	usd
CY2021	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	102407000	usd
CY2023	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	1698730000	usd
CY2022	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	2374849000	usd
CY2021	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	814000000	usd
CY2023	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	1563851000	usd
CY2022	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	2422429000	usd
CY2021	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	788300000	usd
CY2023	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	15000000	usd
CY2022	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	20000000	usd
CY2021	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	usd
CY2023	us-gaap	Early Repayment Of Subordinated Debt EarlyRepaymentOfSubordinatedDebt	0	usd
CY2022	us-gaap	Early Repayment Of Subordinated Debt EarlyRepaymentOfSubordinatedDebt	9090000	usd
CY2021	us-gaap	Early Repayment Of Subordinated Debt EarlyRepaymentOfSubordinatedDebt	0	usd
CY2023	us-gaap	Repayments Of Other Long Term Debt RepaymentsOfOtherLongTermDebt	0	usd
CY2022	us-gaap	Repayments Of Other Long Term Debt RepaymentsOfOtherLongTermDebt	10076000	usd
CY2021	us-gaap	Repayments Of Other Long Term Debt RepaymentsOfOtherLongTermDebt	0	usd
CY2023	us-gaap	Proceeds From Repayments Of Notes Payable ProceedsFromRepaymentsOfNotesPayable	-6013000	usd
CY2022	us-gaap	Proceeds From Repayments Of Notes Payable ProceedsFromRepaymentsOfNotesPayable	-5132000	usd
CY2021	us-gaap	Proceeds From Repayments Of Notes Payable ProceedsFromRepaymentsOfNotesPayable	9998000	usd
CY2023	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	7578000	usd
CY2022	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	6688000	usd
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	6166000	usd
CY2023	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	875000	usd
CY2022	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	683000	usd
CY2021	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	0	usd
CY2023	fbiz	Proceeds From Issuance Of Common Stock Under The Employee Stock Purchase Plan ProceedsFromIssuanceOfCommonStockUnderTheEmployeeStockPurchasePlan	128000	usd
CY2022	fbiz	Proceeds From Issuance Of Common Stock Under The Employee Stock Purchase Plan ProceedsFromIssuanceOfCommonStockUnderTheEmployeeStockPurchasePlan	134000	usd
CY2021	fbiz	Proceeds From Issuance Of Common Stock Under The Employee Stock Purchase Plan ProceedsFromIssuanceOfCommonStockUnderTheEmployeeStockPurchasePlan	160000	usd
CY2023	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	usd
CY2022	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	11992000	usd
CY2021	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	usd
CY2023	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	2971000	usd
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	6126000	usd
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	5478000	usd
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	491385000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	252194000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	75221000	usd
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	36828000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	45572000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	201000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	102682000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	57110000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	56909000	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
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	57110000	usd
CY2023	us-gaap	Interest Paid Net InterestPaidNet	75533000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	20110000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	13206000	usd
CY2023	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	7456000	usd
CY2022	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	8038000	usd
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	14519000	usd
CY2023	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	190000	usd
CY2022	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	50000	usd
CY2021	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	146000	usd
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	6265000	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	316000	usd
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<div style="margin-top:8pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Use of Estimates. </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">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.</span></div>
CY2023Q4	fbiz	Accrued Interest Receivable On Afs Debt Securities AccruedInterestReceivableOnAFSDebtSecurities	1300000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityAccruedInterestBeforeAllowanceForCreditLoss	38000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	4600000	usd
CY2022Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	2600000	usd
CY2023Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	11100000	usd
CY2023Q4	fbiz	Bank Owned Life Insurance Death Benefits BankOwnedLifeInsuranceDeathBenefits	133700000	usd
CY2022Q4	fbiz	Bank Owned Life Insurance Death Benefits BankOwnedLifeInsuranceDeathBenefits	133800000	usd
CY2022Q4	fbiz	Borrowings Against Cash Surrender Value Of Bank Owned Life Insurance BorrowingsAgainstCashSurrenderValueOfBankOwnedLifeInsurance	0	usd
CY2023Q4	fbiz	Borrowings Against Cash Surrender Value Of Bank Owned Life Insurance BorrowingsAgainstCashSurrenderValueOfBankOwnedLifeInsurance	0	usd
CY2023	us-gaap	Impairment Of Investments ImpairmentOfInvestments	0	usd
CY2022	us-gaap	Impairment Of Investments ImpairmentOfInvestments	0	usd
CY2023	fbiz	Maximum Ownership Percentage That Is Not Consolidated MaximumOwnershipPercentageThatIsNotConsolidated	0.50
CY2023	fbiz	Investment In Corporations Minimum Ownership Percentage For Accounting For Using Equity Method InvestmentInCorporationsMinimumOwnershipPercentageForAccountingForUsingEquityMethod	0.20
CY2023	fbiz	Investment In Corporations Maximum Ownership Percentage For Accounting For At Cost InvestmentInCorporationsMaximumOwnershipPercentageForAccountingForAtCost	0.20
CY2023	fbiz	Investment In Limited Partnerships Maximum Ownership Percentage For Accounting For At Cost InvestmentInLimitedPartnershipsMaximumOwnershipPercentageForAccountingForAtCost	0.03
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-45000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	usd
CY2023	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:107%">Reclassifications. </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:107%">Certain amounts in the 2022 consolidated financial statements have been reclassified to conform to the 2023 presentation. These reclassifications were not material and did not impact previously reported net income or comprehensive income.</span></div>
CY2023Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	32300000	usd
CY2022Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	25800000	usd
CY2023Q4	fbiz	Balances Held At Federal Reserve BalancesHeldAtFederalReserve	106800000	usd
CY2022Q4	fbiz	Balances Held At Federal Reserve BalancesHeldAtFederalReserve	76500000	usd
CY2023Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	107200000	usd
CY2022Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	76900000	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
CY2022Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	239751000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	160000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	27887000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	212024000	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
CY2022Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	12635000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	7000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	372000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	12270000	usd
CY2023	fbiz	Numberofavailableforsalesecuritiessold Numberofavailableforsalesecuritiessold	16	securities
CY2021	fbiz	Numberofavailableforsalesecuritiessold Numberofavailableforsalesecuritiessold	7	securities
CY2022	fbiz	Numberofavailableforsalesecuritiessold Numberofavailableforsalesecuritiessold	0	securities
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	68000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	0	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	92000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	113000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	63000	usd
CY2023	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	-45000	usd
CY2022	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	0	usd
CY2021	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	29000	usd
CY2023	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	5085000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	usd
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	14955000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	22576000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	22569000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	1060000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	1057000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	18970000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	17646000	usd
CY2023Q4	fbiz	Heldtomaturity Securities Debt Maturities Rolling Years Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearsTwoThroughFiveAmortizedCost	3150000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	3116000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	12653000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	11915000	usd
CY2023Q4	fbiz	Heldtomaturity Securities Debt Maturities Rolling Years Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearsSixThroughTenAmortizedCost	0	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	0	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	28352000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	25093000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	0	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	0	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	82551000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	77223000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	4210000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	4173000	usd
CY2023Q4	fbiz	Residential Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Amortized Cost ResidentialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateAmortizedCost	200762000	usd
CY2023Q4	fbiz	Residential Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Fair Value ResidentialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateFairValue	188889000	usd
CY2023Q4	fbiz	Residential Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Amortized Cost ResidentialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost	2289000	usd
CY2023Q4	fbiz	Residential Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Fair Value ResidentialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateFairValue	2160000	usd
CY2023Q4	fbiz	Commercial Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Amortized Cost CommercialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateAmortizedCost	35769000	usd
CY2023Q4	fbiz	Commercial Mortgage Backed Securities Available For Sale Maturity Without Single Maturity Date Fair Value CommercialMortgageBackedSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateFairValue	30894000	usd
CY2023Q4	fbiz	Commercial Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Amortized Cost CommercialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost	2004000	usd
CY2023Q4	fbiz	Commercial Mortgage Backed Securities Held To Maturity Maturity Without Single Maturity Date Fair Value CommercialMortgageBackedSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateFairValue	1922000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	319082000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	297006000	usd
CY2023Q4	fbiz	Debt Securities Held To Maturity Maturity Without Single Maturity Date Amortized Cost DebtSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost	8503000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	8255000	usd
CY2023	us-gaap	Other Than Temporary Impairment Loss Debt Securities Available For Sale Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesAvailableForSaleRecognizedInEarnings	0	usd
CY2022	us-gaap	Other Than Temporary Impairment Loss Debt Securities Available For Sale Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesAvailableForSaleRecognizedInEarnings	0	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
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	116851000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	11097000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	82519000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	16790000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	199370000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	27887000	usd
CY2023Q4	us-gaap	Held To Maturity Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions HeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions	29	securities
CY2023Q4	fbiz	Heldto Maturity Securities Securitiesin Unrealized Loss Positions Qualitative Disclosures Numberof Positions12monthsorgreater HeldtoMaturitySecuritiesSecuritiesinUnrealizedLossPositionsQualitativeDisclosuresNumberofPositions12monthsorgreater	24	securities
CY2022	us-gaap	Other Than Temporary Impairment Losses Investments Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsHeldtomaturitySecurities	0	usd
CY2023	us-gaap	Other Than Temporary Impairment Losses Investments Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsHeldtomaturitySecurities	0	usd
CY2021	us-gaap	Other Than Temporary Impairment Losses Investments Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsHeldtomaturitySecurities	0	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
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	10901000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	354000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	267000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	18000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	11168000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	372000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Before Fees Gross LoansAndLeasesReceivableBeforeFeesGross	2850018000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Before Fees Gross LoansAndLeasesReceivableBeforeFeesGross	2443215000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	31275000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	24230000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	-243000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	149000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2818986000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2418836000	usd
CY2023	fbiz	Guaranteed Portionof Sba Loans Soldto Third Parties Total GuaranteedPortionofSBALoansSoldtoThirdPartiesTotal	23600000	usd
CY2022	fbiz	Guaranteed Portionof Sba Loans Soldto Third Parties Total GuaranteedPortionofSBALoansSoldtoThirdPartiesTotal	29900000	usd
CY2023Q4	fbiz	Totalamountofoutstanding Sb Aloanssold TotalamountofoutstandingSBAloanssold	84200000	usd
CY2022Q4	fbiz	Totalamountofoutstanding Sb Aloanssold TotalamountofoutstandingSBAloanssold	88500000	usd
CY2023	fbiz	Loans And Leases Transferred To Third Parties Total Principal Amount LoansAndLeasesTransferredToThirdPartiesTotalPrincipalAmount	120000000	usd
CY2022	fbiz	Loans And Leases Transferred To Third Parties Total Principal Amount LoansAndLeasesTransferredToThirdPartiesTotalPrincipalAmount	96000000	usd
CY2023	fbiz	Gain Loss Recognizedon Participation Interestin Originated Loans GainLossRecognizedonParticipationInterestinOriginatedLoans	0	usd
CY2023Q4	fbiz	Total Amount Of Outstanding Loans Transferred To Third Parties As Loan Participations TotalAmountOfOutstandingLoansTransferredToThirdPartiesAsLoanParticipations	279500000	usd
CY2022Q4	fbiz	Total Amount Of Outstanding Loans Transferred To Third Parties As Loan Participations TotalAmountOfOutstandingLoansTransferredToThirdPartiesAsLoanParticipations	222900000	usd
CY2023Q4	fbiz	Total Amount Of Loan Participations Remaining On Corporations Balance Sheet TotalAmountOfLoanParticipationsRemainingOnCorporationsBalanceSheet	367400000	usd
CY2022Q4	fbiz	Total Amount Of Loan Participations Remaining On Corporations Balance Sheet TotalAmountOfLoanParticipationsRemainingOnCorporationsBalanceSheet	339000000	usd
CY2023Q4	fbiz	Loans In Participation Sold Portfolio Considered Impaired LoansInParticipationSoldPortfolioConsideredImpaired	0	usd
CY2022Q4	fbiz	Loans In Participation Sold Portfolio Considered Impaired LoansInParticipationSoldPortfolioConsideredImpaired	0	usd
CY2023Q4	fbiz	Loan Participations Purchased On Corporations Balance Sheet LoanParticipationsPurchasedOnCorporationsBalanceSheet	0	usd
CY2022Q4	fbiz	Loan Participations Purchased On Corporations Balance Sheet LoanParticipationsPurchasedOnCorporationsBalanceSheet	0	usd
CY2023	fbiz	Loans And Loan Participations Sold LoansAndLoanParticipationsSold	143594000	usd
CY2022	fbiz	Loans And Loan Participations Sold LoansAndLoanParticipationsSold	125855000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	224000	usd
CY2021Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	1288000	usd
CY2023	us-gaap	Loans And Leases Receivable Related Parties Additions LoansAndLeasesReceivableRelatedPartiesAdditions	349000	usd
CY2022	us-gaap	Loans And Leases Receivable Related Parties Additions LoansAndLeasesReceivableRelatedPartiesAdditions	656000	usd
CY2023	us-gaap	Loans And Leases Receivable Related Parties Proceeds LoansAndLeasesReceivableRelatedPartiesProceeds	310000	usd
CY2022	us-gaap	Loans And Leases Receivable Related Parties Proceeds LoansAndLeasesReceivableRelatedPartiesProceeds	1560000	usd
CY2023	fbiz	Changeduetostatusofofficersanddirectors Changeduetostatusofofficersanddirectors	0	usd
CY2022	fbiz	Changeduetostatusofofficersanddirectors Changeduetostatusofofficersanddirectors	-160000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	263000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	224000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Payments To Be Received SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived	9660000	usd
CY2022Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Payments To Be Received SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived	10673000	usd
CY2023Q4	us-gaap	Direct Financing Lease Unguaranteed Residual Asset DirectFinancingLeaseUnguaranteedResidualAsset	1468000	usd
CY2022Q4	us-gaap	Direct Financing Lease Unguaranteed Residual Asset DirectFinancingLeaseUnguaranteedResidualAsset	2776000	usd
CY2023Q4	us-gaap	Direct Financing Lease Deferred Selling Profit DirectFinancingLeaseDeferredSellingProfit	1362000	usd
CY2022Q4	us-gaap	Direct Financing Lease Deferred Selling Profit DirectFinancingLeaseDeferredSellingProfit	1300000	usd
CY2023Q4	us-gaap	Direct Financing Lease Net Investment In Lease DirectFinancingLeaseNetInvestmentInLease	9766000	usd
CY2022Q4	us-gaap	Direct Financing Lease Net Investment In Lease DirectFinancingLeaseNetInvestmentInLease	12149000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Payments To Be Received Next Rolling Twelve Months SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedNextRollingTwelveMonths	3268000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Lease Payments To Be Received Rolling Year Two SalesTypeAndDirectFinancingLeasesLeaseReceivableLeasePaymentsToBeReceivedRollingYearTwo	2425000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Lease Payments To Be Received Rolling Year Three SalesTypeAndDirectFinancingLeasesLeaseReceivableLeasePaymentsToBeReceivedRollingYearThree	1788000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Payments To Be Received Rolling Year Four SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedRollingYearFour	1301000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Lease Payments To Be Received Rolling Year Five SalesTypeAndDirectFinancingLeasesLeaseReceivableLeasePaymentsToBeReceivedRollingYearFive	626000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Lease Payments To Be Received After Rolling Year Five SalesTypeAndDirectFinancingLeasesLeaseReceivableLeasePaymentsToBeReceivedAfterRollingYearFive	252000	usd
CY2023Q4	us-gaap	Sales Type And Direct Financing Leases Lease Receivable Payments To Be Received SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived	9660000	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
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	427044000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	351683000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	368525000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	181687000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	169368000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	491479000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	453429000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	2443215000	usd
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
CY2022Q4	us-gaap	Loans And Leases Receivable Before Fees Gross LoansAndLeasesReceivableBeforeFeesGross	2443215000	usd
CY2022Q4	fbiz	Financing Receivable Recorded Investment30 To59 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestment30To59DaysPastDuePercentOfPortfolio	0.0009
CY2022Q4	fbiz	Financing Receivable Recorded Investment60 To89 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestment60To89DaysPastDuePercentOfPortfolio	0.0002
CY2022Q4	fbiz	Financing Receivable Recorded Investment Equal To Greater Than90 Days Past Due Percent Of Portfolio FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDuePercentOfPortfolio	0.0010
CY2022Q4	fbiz	Financing Receivable Recorded Investment Past Due Percent Of Portfolio FinancingReceivableRecordedInvestmentPastDuePercentOfPortfolio	0.0021
CY2022Q4	fbiz	Financing Receivable Recorded Investment Current Percent Of Portfolio FinancingReceivableRecordedInvestmentCurrentPercentOfPortfolio	0.9979
CY2022Q4	fbiz	Financing Receivable Recorded Investment Gross Percent Of Portfolio FinancingReceivableRecordedInvestmentGrossPercentOfPortfolio	1.0000
CY2023Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	20597000	usd
CY2022Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	3659000	usd
CY2023Q4	us-gaap	Foreclosed Assets ForeclosedAssets	247000	usd
CY2022Q4	us-gaap	Foreclosed Assets ForeclosedAssets	95000	usd
CY2023Q4	fbiz	Total Nonperforming Assets TotalNonperformingAssets	20844000	usd
CY2022Q4	fbiz	Total Nonperforming Assets TotalNonperformingAssets	3754000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Ratio Of Nonperforming Loans To All Loans LoansAndLeasesReceivableRatioOfNonperformingLoansToAllLoans	0.0072
CY2022Q4	us-gaap	Loans And Leases Receivable Ratio Of Nonperforming Loans To All Loans LoansAndLeasesReceivableRatioOfNonperformingLoansToAllLoans	0.0015
CY2023Q4	fbiz	Ratio Of Total Nonperforming Assets To Gross Loans And Leases Plus Foreclosed Properties Net RatioOfTotalNonperformingAssetsToGrossLoansAndLeasesPlusForeclosedPropertiesNet	0.0073
CY2022Q4	fbiz	Ratio Of Total Nonperforming Assets To Gross Loans And Leases Plus Foreclosed Properties Net RatioOfTotalNonperformingAssetsToGrossLoansAndLeasesPlusForeclosedPropertiesNet	0.0015
CY2023Q4	fbiz	Ratio Of Total Nonperforming Assets To Total Assets RatioOfTotalNonperformingAssetsToTotalAssets	0.0059
CY2022Q4	fbiz	Ratio Of Total Nonperforming Assets To Total Assets RatioOfTotalNonperformingAssetsToTotalAssets	0.0013
CY2023Q4	fbiz	Ratio Of Allowance For Loan And Lease Losses To Total Gross Loans And Leases RatioOfAllowanceForLoanAndLeaseLossesToTotalGrossLoansAndLeases	0.0116
CY2022Q4	fbiz	Ratio Of Allowance For Loan And Lease Losses To Total Gross Loans And Leases RatioOfAllowanceForLoanAndLeaseLossesToTotalGrossLoansAndLeases	0.0099
CY2023Q4	fbiz	Ratio Of Allowance For Loan And Leases Losses To Non Accrual Loans And Leases RatioOfAllowanceForLoanAndLeasesLossesToNonAccrualLoansAndLeases	1.6021
CY2022Q4	fbiz	Ratio Of Allowance For Loan And Leases Losses To Non Accrual Loans And Leases RatioOfAllowanceForLoanAndLeasesLossesToNonAccrualLoansAndLeases	6.6220
CY2023	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	3	loans
CY2022	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	0	loans
CY2023	fbiz	Financing Receivable Modifications Subsequent Default Number Of Contracts FinancingReceivableModificationsSubsequentDefaultNumberOfContracts	1	loans
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Modified Subsequent Default FinancingReceivableExcludingAccruedInterestModifiedSubsequentDefault	382000	usd
CY2022	fbiz	Financing Receivable Modifications Subsequent Default Number Of Contracts FinancingReceivableModificationsSubsequentDefaultNumberOfContracts	0	loans
CY2023Q4	fbiz	Unfunded Commitments Troubled Debt Restructurings UnfundedCommitmentsTroubledDebtRestructurings	0	usd
CY2023Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	9691000	usd
CY2023Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	9695000	usd
CY2023	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	4993000	usd
CY2023	fbiz	Impaired Financing Receivable With No Related Allowance Foregone Interest Income ImpairedFinancingReceivableWithNoRelatedAllowanceForegoneInterestIncome	786000	usd
CY2023	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod	237000	usd
CY2023	fbiz	Impaired Financing Receivable With No Related Allowance Net Foregone Interest Income ImpairedFinancingReceivableWithNoRelatedAllowanceNetForegoneInterestIncome	549000	usd
CY2023Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	10906000	usd
CY2023Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	10917000	usd
CY2023Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	5990000	usd
CY2023	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	5457000	usd
CY2023	fbiz	Impaired Financing Receivable With Related Allowance Foregone Interest Income ImpairedFinancingReceivableWithRelatedAllowanceForegoneInterestIncome	645000	usd
CY2023	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod	29000	usd
CY2023	fbiz	Impaired Financing Receivable With Related Allowance Net Foregone Interest Income ImpairedFinancingReceivableWithRelatedAllowanceNetForegoneInterestIncome	616000	usd
CY2023Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	20597000	usd
CY2023Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	20612000	usd
CY2023Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	5990000	usd
CY2023	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	10450000	usd
CY2023	fbiz	Impaired Financing Receivable Foregone Interest Income ImpairedFinancingReceivableForegoneInterestIncome	1431000	usd
CY2023	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	266000	usd
CY2023	fbiz	Impaired Financing Receivable Net Foregone Interest Income ImpairedFinancingReceivableNetForegoneInterestIncome	1165000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	1067000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	1072000	usd
CY2022	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	3445000	usd
CY2022	fbiz	Impaired Financing Receivable With No Related Allowance Foregone Interest Income ImpairedFinancingReceivableWithNoRelatedAllowanceForegoneInterestIncome	299000	usd
CY2022	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod	1435000	usd
CY2022	fbiz	Impaired Financing Receivable With No Related Allowance Net Foregone Interest Income ImpairedFinancingReceivableWithNoRelatedAllowanceNetForegoneInterestIncome	-1136000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	2592000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	2612000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	1650000	usd
CY2022	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	1454000	usd
CY2022	fbiz	Impaired Financing Receivable With Related Allowance Foregone Interest Income ImpairedFinancingReceivableWithRelatedAllowanceForegoneInterestIncome	101000	usd
CY2022	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod	1000	usd
CY2022	fbiz	Impaired Financing Receivable With Related Allowance Net Foregone Interest Income ImpairedFinancingReceivableWithRelatedAllowanceNetForegoneInterestIncome	100000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	3659000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	3684000	usd
CY2022Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	1650000	usd
CY2022	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	4899000	usd
CY2022	fbiz	Impaired Financing Receivable Foregone Interest Income ImpairedFinancingReceivableForegoneInterestIncome	400000	usd
CY2022	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	1436000	usd
CY2022	fbiz	Impaired Financing Receivable Net Foregone Interest Income ImpairedFinancingReceivableNetForegoneInterestIncome	-1036000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	4419000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	4564000	usd
CY2021	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	12754000	usd
CY2021	fbiz	Impaired Financing Receivable With No Related Allowance Foregone Interest Income ImpairedFinancingReceivableWithNoRelatedAllowanceForegoneInterestIncome	991000	usd
CY2021	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod	446000	usd
CY2021	fbiz	Impaired Financing Receivable With No Related Allowance Net Foregone Interest Income ImpairedFinancingReceivableWithNoRelatedAllowanceNetForegoneInterestIncome	545000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	2156000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	2156000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	1505000	usd
CY2021	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	1506000	usd
CY2021	fbiz	Impaired Financing Receivable With Related Allowance Foregone Interest Income ImpairedFinancingReceivableWithRelatedAllowanceForegoneInterestIncome	113000	usd
CY2021	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod	8000	usd
CY2021	fbiz	Impaired Financing Receivable With Related Allowance Net Foregone Interest Income ImpairedFinancingReceivableWithRelatedAllowanceNetForegoneInterestIncome	105000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	6575000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	6720000	usd
CY2021Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	1505000	usd
CY2021	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	14260000	usd
CY2021	fbiz	Impaired Financing Receivable Foregone Interest Income ImpairedFinancingReceivableForegoneInterestIncome	1104000	usd
CY2021	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	454000	usd
CY2021	fbiz	Impaired Financing Receivable Net Foregone Interest Income ImpairedFinancingReceivableNetForegoneInterestIncome	650000	usd
CY2023Q4	fbiz	Loans And Leases Receivable Difference Between Recorded Investment And Unpaid Principal Balance LoansAndLeasesReceivableDifferenceBetweenRecordedInvestmentAndUnpaidPrincipalBalance	15000	usd
CY2022Q4	fbiz	Loans And Leases Receivable Difference Between Recorded Investment And Unpaid Principal Balance LoansAndLeasesReceivableDifferenceBetweenRecordedInvestmentAndUnpaidPrincipalBalance	26000	usd
CY2022Q4	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	24230000	usd
CY2023	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	1781000	usd
CY2023	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	548000	usd
CY2023	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	-1233000	usd
CY2023	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	8182000	usd
CY2023Q4	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	32997000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	31275000	usd
CY2023Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	1722000	usd
CY2023Q4	fbiz	Financing Receivable Allowance For Credit Loss Including FinancingReceivableAllowanceForCreditLossIncluding	32997000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	24336000	usd
CY2022	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	979000	usd
CY2022	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	4741000	usd
CY2022	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	3762000	usd
CY2022	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-3868000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	24230000	usd
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	28521000	usd
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	3508000	usd
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	5126000	usd
CY2021	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	1618000	usd
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-5803000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	24336000	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
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	22580000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	1650000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	24230000	usd
CY2022Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	2439400000	usd
CY2022Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	3815000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	2443215000	usd
CY2023Q4	us-gaap	Leasehold Improvements Gross LeaseholdImprovementsGross	5557000	usd
CY2022Q4	us-gaap	Leasehold Improvements Gross LeaseholdImprovementsGross	4525000	usd
CY2023Q4	us-gaap	Furniture And Fixtures Gross FurnitureAndFixturesGross	9361000	usd
CY2022Q4	us-gaap	Furniture And Fixtures Gross FurnitureAndFixturesGross	8250000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	14918000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	12775000	usd
CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	8728000	usd
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	8435000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	6190000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	4340000	usd
CY2023	us-gaap	Depreciation Depreciation	961000	usd
CY2022	us-gaap	Depreciation Depreciation	578000	usd
CY2021	us-gaap	Depreciation Depreciation	585000	usd
CY2023	fbiz	Leasehold Improvements Gross Placed In Service During The Year LeaseholdImprovementsGrossPlacedInServiceDuringTheYear	1300000	usd
CY2023	fbiz	Furniture And Fixtures Gross Placed In Service During The Year FurnitureAndFixturesGrossPlacedInServiceDuringTheYear	606000	usd
CY2023	us-gaap	Operating Lease Cost OperatingLeaseCost	1411000	usd
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	1544000	usd
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	1513000	usd
CY2023	us-gaap	Short Term Lease Cost ShortTermLeaseCost	200000	usd
CY2022	us-gaap	Short Term Lease Cost ShortTermLeaseCost	148000	usd
CY2021	us-gaap	Short Term Lease Cost ShortTermLeaseCost	158000	usd
CY2023	us-gaap	Variable Lease Cost VariableLeaseCost	576000	usd
CY2022	us-gaap	Variable Lease Cost VariableLeaseCost	604000	usd
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	492000	usd
CY2023	us-gaap	Sublease Income SubleaseIncome	75000	usd
CY2022	us-gaap	Sublease Income SubleaseIncome	179000	usd
CY2021	us-gaap	Sublease Income SubleaseIncome	170000	usd
CY2023	us-gaap	Lease Cost LeaseCost	2112000	usd
CY2022	us-gaap	Lease Cost LeaseCost	2117000	usd
CY2021	us-gaap	Lease Cost LeaseCost	1993000	usd
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y8M12D
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y21D
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P5Y18D
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0361
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0340
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0251
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	1514000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	1408000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	1400000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	1427000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	1113000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	3600000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	10462000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	1508000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	8954000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	10700000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	10700000	usd
CY2023	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	500000	usd
CY2022	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	634000	usd
CY2021	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	412000	usd
CY2023Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1400000	usd
CY2022Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1500000	usd
CY2023Q4	fbiz	Investmentin Historic Development Entities InvestmentinHistoricDevelopmentEntities	2400000	usd
CY2022Q4	fbiz	Investmentin Historic Development Entities InvestmentinHistoricDevelopmentEntities	2200000	usd
CY2023	fbiz	Capital Contributionsto Historic Rehabilitation Tax Credits CapitalContributionstoHistoricRehabilitationTaxCredits	285000	usd
CY2022	fbiz	Capital Contributionsto Historic Rehabilitation Tax Credits CapitalContributionstoHistoricRehabilitationTaxCredits	0	usd
CY2021	fbiz	Capital Contributionsto Historic Rehabilitation Tax Credits CapitalContributionstoHistoricRehabilitationTaxCredits	0	usd
CY2023Q4	fbiz	Investment In Low Income Housing InvestmentInLowIncomeHousing	33300000	usd
CY2022Q4	fbiz	Investment In Low Income Housing InvestmentInLowIncomeHousing	13500000	usd
CY2023Q4	fbiz	Capital Contributions To Low Income Housing Tax Credits CapitalContributionsToLowIncomeHousingTaxCredits	24000000	usd
CY2022Q4	fbiz	Capital Contributions To Low Income Housing Tax Credits CapitalContributionsToLowIncomeHousingTaxCredits	11500000	usd
CY2021Q4	fbiz	Capital Contributions To Low Income Housing Tax Credits CapitalContributionsToLowIncomeHousingTaxCredits	3000000	usd
CY2023	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	5300000	usd
CY2022	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	1400000	usd
CY2023	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	4100000	usd
CY2022	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1000000	usd
CY2023Q4	us-gaap	Interest Receivable InterestReceivable	13275000	usd
CY2022Q4	us-gaap	Interest Receivable InterestReceivable	9403000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	9508000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	11711000	usd
CY2023Q4	fbiz	Investmentin Historic Development Entities InvestmentinHistoricDevelopmentEntities	2393000	usd
CY2022Q4	fbiz	Investmentin Historic Development Entities InvestmentinHistoricDevelopmentEntities	2176000	usd
CY2023Q4	fbiz	Investment In Low Income Housing InvestmentInLowIncomeHousing	33303000	usd
CY2022Q4	fbiz	Investment In Low Income Housing InvestmentInLowIncomeHousing	13514000	usd
CY2023Q4	fbiz	Investmentin Limited Partnerships InvestmentinLimitedPartnerships	15027000	usd
CY2022Q4	fbiz	Investmentin Limited Partnerships InvestmentinLimitedPartnerships	13599000	usd
CY2023Q4	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	4269000	usd
CY2022Q4	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	3821000	usd
CY2023Q4	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	13283000	usd
CY2022Q4	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	8883000	usd
CY2023Q4	us-gaap	Other Assets OtherAssets	91058000	usd
CY2022Q4	us-gaap	Other Assets OtherAssets	63107000	usd
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
CY2022Q4	us-gaap	Deposits Deposits	2168206000	usd
CY2022	fbiz	Average Balance Deposits AverageBalanceDeposits	1977640000	usd
CY2022	fbiz	Deposits Weighted Average Interest Rate Duringthe Period DepositsWeightedAverageInterestRateDuringthePeriod	0.0067
CY2023Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	536645000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	19081000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	50416000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	73804000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	12821000	usd
CY2023Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	2072000	usd
CY2023Q4	us-gaap	Time Deposits TimeDeposits	694839000	usd
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
CY2022Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	456808000	usd
CY2022	fbiz	Borrowed Funds Average Balance BorrowedFundsAverageBalance	460438000	usd
CY2022	us-gaap	Debt Instrument Interest Rate During Period DebtInstrumentInterestRateDuringPeriod	0.0212
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	120520000	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	48000000	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	65000000	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	28000000	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	0	usd
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	69396000	usd
CY2023Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	330916000	usd
CY2022	us-gaap	Line Of Credit Facility Commitment Fee Amount LineOfCreditFacilityCommitmentFeeAmount	13000	usd
CY2023	us-gaap	Line Of Credit Facility Commitment Fee Amount LineOfCreditFacilityCommitmentFeeAmount	13000	usd
CY2021	us-gaap	Line Of Credit Facility Commitment Fee Amount LineOfCreditFacilityCommitmentFeeAmount	13000	usd
CY2023Q4	us-gaap	Deferred Finance Costs Ownshare Lending Arrangement Issuance Costs Net DeferredFinanceCostsOwnshareLendingArrangementIssuanceCostsNet	573000	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
CY2023	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	875000	usd
CY2022	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	683000	usd
CY2023Q4	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	1000
CY2023	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.
CY2022Q4	us-gaap	Capital Capital	323893000	usd
CY2022Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1126
CY2022Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	230180000	usd
CY2022Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0800
CY2022Q4	fbiz	Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer CapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	302111000	usd
CY2022Q4	fbiz	Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets CapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.1050
CY2022Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	264843000	usd
CY2022Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.0920
CY2022Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	172635000	usd
CY2022Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0600
CY2022Q4	fbiz	Tier One Risk Based Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer TierOneRiskBasedCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	244566000	usd
CY2022Q4	fbiz	Tier One Risk Based Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets TierOneRiskBasedCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0850
CY2022Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	252851000	usd
CY2022Q4	fbiz	Common Equity Tier One Capitalto Risk Weighted Assets CommonEquityTierOneCapitaltoRiskWeightedAssets	0.0879
CY2022Q4	us-gaap	Common Equity Tier One Capital Required For Capital Adequacy CommonEquityTierOneCapitalRequiredForCapitalAdequacy	129476000	usd
CY2022Q4	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacyto Risk Weighted Assets CommonEquityTierOneCapitalRequiredforCapitalAdequacytoRiskWeightedAssets	0.0450
CY2022Q4	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer CommonEquityTierOneCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	201407000	usd
CY2022Q4	fbiz	Common Equity Tier One Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets CommonEquityTierOneCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0700
CY2022Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	264843000	usd
CY2022Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.0917
CY2022Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	115464000	usd
CY2022Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2022Q4	fbiz	Tier One Leverage Capital Requiredfor Capital Adequacy Plus Capital Conservation Buffer TierOneLeverageCapitalRequiredforCapitalAdequacyPlusCapitalConservationBuffer	115464000	usd
CY2022Q4	fbiz	Tier One Leverage Capital Requiredfor Capital Adequacy Plus Conservation Bufferto Risk Weighted Assets TierOneLeverageCapitalRequiredforCapitalAdequacyPlusConservationBuffertoRiskWeightedAssets	0.0400
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	289588000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	260640000	usd
CY2023Q4	us-gaap	Aoci Before Tax Attributable To Parent AociBeforeTaxAttributableToParent	13717000	usd
CY2022Q4	us-gaap	Aoci Before Tax Attributable To Parent AociBeforeTaxAttributableToParent	15310000	usd
CY2023Q4	fbiz	Disallowed Servicing Assetsand Purchased Credit Card Relationships DisallowedServicingAssetsandPurchasedCreditCardRelationships	614000	usd
CY2022Q4	fbiz	Disallowed Servicing Assetsand Purchased Credit Card Relationships DisallowedServicingAssetsandPurchasedCreditCardRelationships	706000	usd
CY2023Q4	fbiz	Disallowed Goodwilland Intangibles DisallowedGoodwillandIntangibles	10368000	usd
CY2022Q4	fbiz	Disallowed Goodwilland Intangibles DisallowedGoodwillandIntangibles	10401000	usd
CY2023	fbiz	Equity Impact Of Asc326 Phase In EquityImpactOfASC326PhaseIn	1015000	usd
CY2022	fbiz	Equity Impact Of Asc326 Phase In EquityImpactOfASC326PhaseIn	0	usd
CY2023Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	293338000	usd
CY2022Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	264843000	usd
CY2023Q4	fbiz	Allowable General Valuation Allowances And Subordinated Debt AllowableGeneralValuationAllowancesAndSubordinatedDebt	82102000	usd
CY2022Q4	fbiz	Allowable General Valuation Allowances And Subordinated Debt AllowableGeneralValuationAllowancesAndSubordinatedDebt	59050000	usd
CY2023Q4	us-gaap	Capital Capital	375440000	usd
CY2022Q4	us-gaap	Capital Capital	323893000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	37027000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	40858000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	35755000	usd
CY2023	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	875000	usd
CY2022	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	683000	usd
CY2021	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	0	usd
CY2023	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	938000	usd
CY2022	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	1106000	usd
CY2021	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	1053000	usd
CY2023	fbiz	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	35214000	usd
CY2022	fbiz	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	39069000	usd
CY2021	fbiz	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	34702000	usd
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	8131251	shares
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	8226943	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	8314921	shares
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.33
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.75
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.17
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	35214000	usd
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	39069000	usd
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	34702000	usd
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	8131251	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	8226943	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	8314921	shares
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.33
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.75
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.17
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	187804	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	24.29
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	93130	shares
CY2021	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	23.57
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	63385	shares
CY2021	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	22.28
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	7760	shares
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	23.24
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	209789	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	24.62
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	103010	shares
CY2022	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	30.47
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	107435	shares
CY2022	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	21.49
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	8507	shares
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	26.15
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
CY2023Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	3501000	usd
CY2023	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P2Y1M24D
CY2023Q4	fbiz	Employee Stock Purchase Plan Number Of Shares Authorized For Grant EmployeeStockPurchasePlanNumberOfSharesAuthorizedForGrant	250000	shares
CY2023Q4	fbiz	Employee Stock Purchase Program Percent Discount EmployeeStockPurchaseProgramPercentDiscount	0.90
CY2023	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	4328	shares
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	2977000	usd
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	2584000	usd
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	2513000	usd
CY2023	fbiz	Defined Contribution Maximum Annual Matching Contribution Per Employee Percent DefinedContributionMaximumAnnualMatchingContributionPerEmployeePercent	0.03
CY2023	fbiz	Defined Contribution Maximum Annual Discretionary Contribution Per Employee Percent DefinedContributionMaximumAnnualDiscretionaryContributionPerEmployeePercent	0.06
CY2023	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.03
CY2023	fbiz	Defined Contribution Plan Employer Matching Contribution DefinedContributionPlanEmployerMatchingContribution	1200000	usd
CY2022	fbiz	Defined Contribution Plan Employer Matching Contribution DefinedContributionPlanEmployerMatchingContribution	1100000	usd
CY2021	fbiz	Defined Contribution Plan Employer Matching Contribution DefinedContributionPlanEmployerMatchingContribution	987000	usd
CY2023	fbiz	Defined Contribution Plan Employer Discretionary Contribution Percent DefinedContributionPlanEmployerDiscretionaryContributionPercent	0.059
CY2023	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	2100000	usd
CY2022	fbiz	Defined Contribution Plan Employer Discretionary Contribution Percent DefinedContributionPlanEmployerDiscretionaryContributionPercent	0.052
CY2022	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	1600000	usd
CY2021	fbiz	Defined Contribution Plan Employer Discretionary Contribution Percent DefinedContributionPlanEmployerDiscretionaryContributionPercent	0.047
CY2021	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	1300000	usd
CY2023	us-gaap	Deferred Compensation Arrangement With Individual Compensation Expense DeferredCompensationArrangementWithIndividualCompensationExpense	493000	usd
CY2022	us-gaap	Deferred Compensation Arrangement With Individual Compensation Expense DeferredCompensationArrangementWithIndividualCompensationExpense	382000	usd
CY2021	us-gaap	Deferred Compensation Arrangement With Individual Compensation Expense DeferredCompensationArrangementWithIndividualCompensationExpense	237000	usd
CY2023Q4	us-gaap	Deferred Compensation Cashbased Arrangements Liability Current And Noncurrent DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent	2800000	usd
CY2022Q4	us-gaap	Deferred Compensation Cashbased Arrangements Liability Current And Noncurrent DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent	2300000	usd
CY2023	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	7759000	usd
CY2022	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	9174000	usd
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	6965000	usd
CY2023	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	233000	usd
CY2022	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	2987000	usd
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	3087000	usd
CY2023	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	7992000	usd
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	12161000	usd
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	10052000	usd
CY2023	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-716000	usd
CY2022	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-733000	usd
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	1333000	usd
CY2023	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	2836000	usd
CY2022	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-42000	usd
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-110000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2120000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-775000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1223000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	10112000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11386000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11275000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	8730000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	6267000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	2094000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	2342000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	875000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	265000	usd
CY2023Q4	fbiz	Deferred Tax Assets Write Down Of Foreclosed Properties DeferredTaxAssetsWriteDownOfForeclosedProperties	10000	usd
CY2022Q4	fbiz	Deferred Tax Assets Write Down Of Foreclosed Properties DeferredTaxAssetsWriteDownOfForeclosedProperties	11000	usd
CY2023Q4	fbiz	Deferred Tax Assets Non Accrual Loan Interest DeferredTaxAssetsNonAccrualLoanInterest	95000	usd
CY2022Q4	fbiz	Deferred Tax Assets Non Accrual Loan Interest DeferredTaxAssetsNonAccrualLoanInterest	47000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Capital Loss Carryforwards DeferredTaxAssetsCapitalLossCarryforwards	22000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Capital Loss Carryforwards DeferredTaxAssetsCapitalLossCarryforwards	21000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	4715000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	5263000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	788000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	725000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	284000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	125000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	17613000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	15066000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	3339000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	usd
CY2023Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	14274000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	15066000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	1854000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2197000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	381000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	393000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2531000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	765000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	4766000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	3355000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	9508000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	11711000	usd
CY2023	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-2203000	usd
CY2022	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	5536000	usd
CY2021	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-1042000	usd
CY2023	fbiz	Deferred Taxes Allocated To Other Comprehensive Income DeferredTaxesAllocatedToOtherComprehensiveIncome	548000	usd
CY2022	fbiz	Deferred Taxes Allocated To Other Comprehensive Income DeferredTaxesAllocatedToOtherComprehensiveIncome	-4761000	usd
CY2021	fbiz	Deferred Taxes Allocated To Other Comprehensive Income DeferredTaxesAllocatedToOtherComprehensiveIncome	-181000	usd
CY2023	fbiz	Deferred Income Tax Benefit Expense Impact Of Cumulative Change In Accounting Principle DeferredIncomeTaxBenefitExpenseImpactOfCumulativeChangeInAccountingPrinciple	465000	usd
CY2022	fbiz	Deferred Income Tax Benefit Expense Impact Of Cumulative Change In Accounting Principle DeferredIncomeTaxBenefitExpenseImpactOfCumulativeChangeInAccountingPrinciple	0	usd
CY2021	fbiz	Deferred Income Tax Benefit Expense Impact Of Cumulative Change In Accounting Principle DeferredIncomeTaxBenefitExpenseImpactOfCumulativeChangeInAccountingPrinciple	0	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2120000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-775000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1223000	usd
CY2023	us-gaap	Tax Adjustments Settlements And Unusual Provisions TaxAdjustmentsSettlementsAndUnusualProvisions	2800000	usd
CY2023	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	2800000	usd
CY2023Q4	fbiz	Income Tax Expense Change In Amount IncomeTaxExpenseChangeInAmount	2800000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	3300000	usd
CY2023Q4	us-gaap	Deferred Tax Assets State Taxes DeferredTaxAssetsStateTaxes	0	usd
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	47139000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	52244000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	47030000	usd
CY2023	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	9899000	usd
CY2022	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	10971000	usd
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	9876000	usd
CY2023	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	-52000	usd
CY2022	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	2337000	usd
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	2351000	usd
CY2023	fbiz	Income Tax Reconciliation Tax Exempt Income Tax Exempt Security And Loan Income Net Of Tefra Adjustments IncomeTaxReconciliationTaxExemptIncomeTaxExemptSecurityAndLoanIncomeNetOfTefraAdjustments	856000	usd
CY2022	fbiz	Income Tax Reconciliation Tax Exempt Income Tax Exempt Security And Loan Income Net Of Tefra Adjustments IncomeTaxReconciliationTaxExemptIncomeTaxExemptSecurityAndLoanIncomeNetOfTefraAdjustments	704000	usd
CY2021	fbiz	Income Tax Reconciliation Tax Exempt Income Tax Exempt Security And Loan Income Net Of Tefra Adjustments IncomeTaxReconciliationTaxExemptIncomeTaxExemptSecurityAndLoanIncomeNetOfTefraAdjustments	710000	usd
CY2023	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	3349000	usd
CY2022	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	usd
CY2021	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	usd
CY2023	fbiz	Income Tax Reconciliation Tax Exempt Income Bank Owned Life Insurance IncomeTaxReconciliationTaxExemptIncomeBankOwnedLifeInsurance	313000	usd
CY2022	fbiz	Income Tax Reconciliation Tax Exempt Income Bank Owned Life Insurance IncomeTaxReconciliationTaxExemptIncomeBankOwnedLifeInsurance	468000	usd
CY2021	fbiz	Income Tax Reconciliation Tax Exempt Income Bank Owned Life Insurance IncomeTaxReconciliationTaxExemptIncomeBankOwnedLifeInsurance	297000	usd
CY2023	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	1045000	usd
CY2022	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	338000	usd
CY2021	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	0	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-159000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-392000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	0	usd
CY2023	fbiz	Effective Income Tax Rate Reconciliation Section162m Limitation Amount EffectiveIncomeTaxRateReconciliationSection162mLimitationAmount	123000	usd
CY2022	fbiz	Effective Income Tax Rate Reconciliation Section162m Limitation Amount EffectiveIncomeTaxRateReconciliationSection162mLimitationAmount	118000	usd
CY2021	fbiz	Effective Income Tax Rate Reconciliation Section162m Limitation Amount EffectiveIncomeTaxRateReconciliationSection162mLimitationAmount	0	usd
CY2023	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-834000	usd
CY2022	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-138000	usd
CY2021	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	55000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	10112000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11386000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11275000	usd
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2145
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2179
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2397
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	usd
CY2023Q4	us-gaap	Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit	0	usd
CY2023Q4	fbiz	Accumulated Derivative Credit Valuation Adjustment AccumulatedDerivativeCreditValuationAdjustment	117000	usd
CY2022Q4	fbiz	Accumulated Derivative Credit Valuation Adjustment AccumulatedDerivativeCreditValuationAdjustment	38000	usd
CY2023	us-gaap	Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet	0	usd
CY2023Q4	fbiz	Accrued Credit Losses For Financial Instruments With Off Balance Sheet Risk AccruedCreditLossesForFinancialInstrumentsWithOffBalanceSheetRisk	0	usd
CY2022Q4	fbiz	Accrued Credit Losses For Financial Instruments With Off Balance Sheet Risk AccruedCreditLossesForFinancialInstrumentsWithOffBalanceSheetRisk	0	usd
CY2023Q4	fbiz	Sba Loans Probabilityof Future Losses SBALoansProbabilityofFutureLosses	955000	usd
CY2022Q4	fbiz	Sba Loans Probabilityof Future Losses SBALoansProbabilityofFutureLosses	441000	usd
CY2022Q4	fbiz	Sba Recourse Reserve SBARecourseReserve	441000	usd
CY2021Q4	fbiz	Sba Recourse Reserve SBARecourseReserve	635000	usd
CY2023	fbiz	Sba Recourse Provision SBARecourseProvision	775000	usd
CY2022	fbiz	Sba Recourse Provision SBARecourseProvision	-188000	usd
CY2023	fbiz	Sba Loan Charge Offs Net SBALoanChargeOffsNet	-261000	usd
CY2022	fbiz	Sba Loan Charge Offs Net SBALoanChargeOffsNet	-6000	usd
CY2023Q4	fbiz	Sba Recourse Reserve SBARecourseReserve	955000	usd
CY2022Q4	fbiz	Sba Recourse Reserve SBARecourseReserve	441000	usd
CY2023	fbiz	Fair Value Assets Level2to Level1 Transfers Amount1 FairValueAssetsLevel2toLevel1TransfersAmount1	0	usd
CY2022	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	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
CY2022	fbiz	Fair Value Liabilities Level2to Level1 Transfers Amount1 FairValueLiabilitiesLevel2toLevel1TransfersAmount1	0	usd
CY2023	fbiz	Fair Value Liabilities Level1to Level2 Transfers Amount1 FairValueLiabilitiesLevel1toLevel2TransfersAmount1	0	usd
CY2022	fbiz	Fair Value Liabilities Level1to Level2 Transfers Amount1 FairValueLiabilitiesLevel1toLevel2TransfersAmount1	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	0	usd
CY2022	fbiz	Fair Value Assets Level1to Level2 Transfers Amount1 FairValueAssetsLevel1toLevel2TransfersAmount1	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3	0	usd
CY2022	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	usd
CY2022	fbiz	Fair Value Assets Level2to Level1 Transfers Amount1 FairValueAssetsLevel2toLevel1TransfersAmount1	0	usd
CY2022	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	usd
CY2022	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 Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3	0	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
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	102682000	usd
CY2022Q4	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	102682000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	212024000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	212024000	usd
CY2022Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	12635000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	12270000	usd
CY2022Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	2632000	usd
CY2022Q4	us-gaap	Loans Held For Sale Fair Value Disclosure LoansHeldForSaleFairValueDisclosure	2829000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	2418836000	usd
CY2022Q4	us-gaap	Loans Receivable Fair Value Disclosure LoansReceivableFairValueDisclosure	2394702000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	17812000	usd
CY2022Q4	us-gaap	Interest Receivable InterestReceivable	9403000	usd
CY2022Q4	fbiz	Accrued Interest Receivable Fair Value Disclosure AccruedInterestReceivableFairValueDisclosure	9403000	usd
CY2022Q4	us-gaap	Deposits Deposits	2168206000	usd
CY2022Q4	us-gaap	Deposits Fair Value Disclosure DepositsFairValueDisclosure	2167444000	usd
CY2022Q4	fbiz	Federal Home Loan Bank And Other Borrowings FederalHomeLoanBankAndOtherBorrowings	456808000	usd
CY2022Q4	fbiz	Federal Home Loan Bank And Other Borrowings Fair Value Disclosure FederalHomeLoanBankAndOtherBorrowingsFairValueDisclosure	440242000	usd
CY2022Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	4053000	usd
CY2022Q4	us-gaap	Accrued Liabilities Fair Value Disclosure AccruedLiabilitiesFairValueDisclosure	4053000	usd
CY2022Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	184000	usd
CY2022Q4	fbiz	Standby Letters Of Credit Fair Value Disclosure StandbyLettersOfCreditFairValueDisclosure	184000	usd
CY2022Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	25884000	usd
CY2022Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	23660000	usd
CY2022Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	21426000	usd
CY2023Q4	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2573000	usd
CY2023Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1817000	usd
CY2023Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2231000	usd
CY2023Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1561000	usd
CY2023	fbiz	Capital Contributions To Subsidiaries Investing Activities CapitalContributionsToSubsidiariesInvestingActivities	15000000	usd
CY2022	fbiz	Capital Contributions To Subsidiaries Investing Activities CapitalContributionsToSubsidiariesInvestingActivities	0	usd
CY2021	fbiz	Capital Contributions To Subsidiaries Investing Activities CapitalContributionsToSubsidiariesInvestingActivities	0	usd
CY2023	fbiz	Proceeds From Purchases Of Employee Stock Purchase Plan Shares ProceedsFromPurchasesOfEmployeeStockPurchasePlanShares	128000	usd
CY2022	fbiz	Proceeds From Purchases Of Employee Stock Purchase Plan Shares ProceedsFromPurchasesOfEmployeeStockPurchasePlanShares	134000	usd
CY2021	fbiz	Proceeds From Purchases Of Employee Stock Purchase Plan Shares ProceedsFromPurchasesOfEmployeeStockPurchasePlanShares	160000	usd
CY2023Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	54762000	usd
CY2023Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	50941000	usd
CY2023Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	47161000	usd
CY2023Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	42064000	usd
CY2022Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	38319000	usd
CY2022Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	31786000	usd
CY2022Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	27031000	usd
CY2022Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	24235000	usd
CY2023Q4	us-gaap	Interest Expense InterestExpense	25222000	usd
CY2023Q3	us-gaap	Interest Expense InterestExpense	22345000	usd
CY2023Q2	us-gaap	Interest Expense InterestExpense	19414000	usd
CY2023Q1	us-gaap	Interest Expense InterestExpense	15359000	usd
CY2022Q4	us-gaap	Interest Expense InterestExpense	10867000	usd
CY2022Q3	us-gaap	Interest Expense InterestExpense	5902000	usd
CY2022Q2	us-gaap	Interest Expense InterestExpense	3371000	usd
CY2022Q1	us-gaap	Interest Expense InterestExpense	2809000	usd
CY2023Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	29540000	usd
CY2023Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	28596000	usd
CY2023Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	27747000	usd
CY2023Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	26705000	usd
CY2022Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	27452000	usd
CY2022Q4	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	702000	usd
CY2022Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	12000	usd
CY2022Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-3727000	usd
CY2022Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-855000	usd
CY2023Q4	us-gaap	Noninterest Income NoninterestIncome	7094000	usd
CY2023Q3	us-gaap	Noninterest Income NoninterestIncome	8430000	usd
CY2023Q2	us-gaap	Noninterest Income NoninterestIncome	7374000	usd
CY2023Q1	us-gaap	Noninterest Income NoninterestIncome	8410000	usd
CY2022Q4	us-gaap	Noninterest Income NoninterestIncome	6973000	usd
CY2022Q3	us-gaap	Noninterest Income NoninterestIncome	8197000	usd
CY2022Q2	us-gaap	Noninterest Income NoninterestIncome	6872000	usd
CY2022Q1	us-gaap	Noninterest Income NoninterestIncome	7386000	usd
CY2023Q4	us-gaap	Noninterest Expense NoninterestExpense	21588000	usd
CY2023Q3	us-gaap	Noninterest Expense NoninterestExpense	23189000	usd
CY2023Q2	us-gaap	Noninterest Expense NoninterestExpense	22031000	usd
CY2023Q1	us-gaap	Noninterest Expense NoninterestExpense	21767000	usd
CY2022Q4	us-gaap	Noninterest Expense NoninterestExpense	21167000	usd
CY2022Q3	us-gaap	Noninterest Expense NoninterestExpense	20028000	usd
CY2022Q2	us-gaap	Noninterest Expense NoninterestExpense	19456000	usd
CY2022Q1	us-gaap	Noninterest Expense NoninterestExpense	18823000	usd
CY2023Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	12473000	usd
CY2023Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	12020000	usd
CY2023Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	10859000	usd
CY2023Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	11787000	usd
CY2022Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	12556000	usd
CY2022Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	14041000	usd
CY2022Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	14803000	usd
CY2022Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	10844000	usd
CY2023Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2703000	usd
CY2023Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2079000	usd
CY2023Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2522000	usd
CY2023Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2808000	usd
CY2022Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2400000	usd
CY2022Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3215000	usd
CY2022Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3599000	usd
CY2022Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2172000	usd
CY2023Q4	us-gaap	Net Income Loss NetIncomeLoss	9770000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	9941000	usd
CY2023Q2	us-gaap	Net Income Loss NetIncomeLoss	8337000	usd
CY2023Q1	us-gaap	Net Income Loss NetIncomeLoss	8979000	usd
CY2022Q4	us-gaap	Net Income Loss NetIncomeLoss	10156000	usd
CY2022Q3	us-gaap	Net Income Loss NetIncomeLoss	10826000	usd
CY2022Q2	us-gaap	Net Income Loss NetIncomeLoss	11204000	usd
CY2022Q1	us-gaap	Net Income Loss NetIncomeLoss	8672000	usd
CY2023Q4	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	219000	usd
CY2023Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	218000	usd
CY2023Q2	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	219000	usd
CY2023Q1	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	219000	usd
CY2022Q4	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	219000	usd
CY2022Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	219000	usd
CY2022Q2	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	245000	usd
CY2022Q1	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	0	usd
CY2023Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	9551000	usd
CY2023Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	9723000	usd
CY2023Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	8118000	usd
CY2023Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	8760000	usd
CY2022Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	9937000	usd
CY2022Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	10607000	usd
CY2022Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	10959000	usd
CY2022Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	8672000	usd
CY2023Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.15
CY2023Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.17
CY2023Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.98
CY2023Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.05
CY2022Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.18
CY2022Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.25
CY2022Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.29
CY2022Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.02
CY2023Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.15
CY2023Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.17
CY2023Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.98
CY2023Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.05
CY2022Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.18
CY2022Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.25
CY2022Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.29
CY2022Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.02
CY2023Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.2275
CY2023Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.2275
CY2023Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.2275
CY2023Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.2275
CY2022Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1975
CY2022Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1975
CY2022Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1975
CY2022Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1975
CY2023	dei	Auditor Name AuditorName	Crowe LLP
CY2023	dei	Auditor Location AuditorLocation	Oak Brook, Illinois

Files In Submission

Name	View Source	Status
fbiz-20231231_cal.xml	Edgar Link	unprocessable
0001521951-24-000020-index-headers.html	Edgar Link	pending
0001521951-24-000020-index.html	Edgar Link	pending
0001521951-24-000020.txt	Edgar Link	pending
0001521951-24-000020-xbrl.zip	Edgar Link	pending
fbiz-20231231.htm	Edgar Link	pending
fbiz-20231231.xsd	Edgar Link	pending
fbiz-20231231_g1.jpg	Edgar Link	pending
fbiz20231231exhibit21.htm	Edgar Link	pending
fbiz20231231exhibit23.htm	Edgar Link	pending
fbiz20231231exhibit311.htm	Edgar Link	pending
fbiz20231231exhibit312.htm	Edgar Link	pending
fbiz20231231exhibit32.htm	Edgar Link	pending
fbiz20231231exhibit42.htm	Edgar Link	pending
fbiz20231231exhibit97.htm	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R105.htm	Edgar Link	pending
R106.htm	Edgar Link	pending
R107.htm	Edgar Link	pending
R108.htm	Edgar Link	pending
R109.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R110.htm	Edgar Link	pending
R111.htm	Edgar Link	pending
R112.htm	Edgar Link	pending
R113.htm	Edgar Link	pending
R114.htm	Edgar Link	pending
R115.htm	Edgar Link	pending
R116.htm	Edgar Link	pending
R117.htm	Edgar Link	pending
R118.htm	Edgar Link	pending
R119.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R120.htm	Edgar Link	pending
R121.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
fbiz-20231231_def.xml	Edgar Link	unprocessable
fbiz-20231231_lab.xml	Edgar Link	unprocessable
fbiz-20231231_pre.xml	Edgar Link	unprocessable
fbiz-20231231_htm.xml	Edgar Link	completed
FilingSummary.xml	Edgar Link	unprocessable
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
R9999.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

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

2024 Q1 Form 10-K Financial Statement

#000152195124000020 Filed on February 28, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

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

2024 Q1 Form 10-K Financial Statement

#000152195124000020 Filed on February 28, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

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