Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Schedule of Goodwill and Intangible Assets Intangible Asset and Goodwill [Table Text Block] Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Trading Arrangement: Trading Arrangement [Axis] Nonaccrual credit relationships Material Loans Criteria For ACL-Loans Adequacy Calculation Material Loans Criteria For ACL-Loans Adequacy Calculation Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Title of 12(b) Security Title of 12(b) Security Carrying Amount Reported Value Measurement [Member] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Document Fiscal Year Focus Document Fiscal Year Focus Valuation allowance at beginning of year Valuation allowance at end of period Valuation Allowance for Impairment of Recognized Servicing Assets, Balance Merger-related expense Business Combination, Acquisition-Related Cost, Expense Forward commitments to sell residential mortgage loans Forward Commitments [Member] Forward Commitments Schedule of Assets Measured at Fair Value on a Nonrecurring Basis Fair Value Measurements, Nonrecurring [Table Text Block] Net (charge-offs) recoveries Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) Adjustment to Compensation, Amount Adjustment to Compensation Amount Financial Instrument [Axis] Financial Instrument [Axis] Restricted Shares Outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] % of Total Percentage Of Total Notes Receivable, Gross Represents the percentage of loan under each category to total loan. Schedule of Estimated Future Amortization Expense for Amortizing Intangible Assets and the MSR Asset Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense [Table Text Block] Total deposits Deposits Deposits Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Depreciation, amortization, and accretion Depreciation, Amortization and Accretion, Net Schedule of Components of Long-term Borrowings Schedule of Long-Term Debt Instruments [Table Text Block] Capitalized servicing rights Servicing Asset At Amortized Value Capitalization Represents the amount related to capitalization of servicing asset. Restatement Determination Date Restatement Determination Date Percent of total loans Financing Receivable, Excluding Accrued Interest, Nonaccrual, Percent Past Due Cash paid per acquiree share (in shares) Business Combination, Consideration Transferred, Equity Interests Issued And Issuable, Cash Paid Per Acquiree Share Business Combination, Consideration Transferred, Equity Interests Issued And Issuable, Cash Paid Per Acquiree Share Derivative Instrument [Axis] Derivative Instrument [Axis] Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] Due after five years through ten years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 5 through 10 Years, Fair Value Other noninterest expense Other Noninterest Expense Investment securities Business Combination, Recognized Asset Acquired, Investment in Debt and Equity Securities, Current Measurement Frequency [Axis] Measurement Frequency [Axis] Junior subordinated debentures Junior Subordinated Debt [Member] PCD loans aquired Financial Asset Acquired with Credit Deterioration [Member] Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Federal Reserve Bank stock Federal Reserve Bank Stock ATBancorp Statutory Trust II ATBancorp Statutory Trust II [Member] ATBancorp Statutory Trust II Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Performance standby letters of credit Standby Letters of Credit [Member] Premises and equipment Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Schedule of Amortized Cost and Fair Value of Securities AFS Debt Securities, Available-for-Sale [Table Text Block] Origination of loans held for sale Payment for Origination, Loan, Mortgage, Held-for-Sale Loans Insured or Guaranteed by US Government Authorities Loans Insured or Guaranteed by US Government Authorities [Member] Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Interest Rate Reduction Contractual Interest Rate Reduction [Member] Issuance of common stock in acquisition Stock Issued During Period, Value, Acquisitions Servicing Asset at Fair Value, Amount [Roll Forward] Servicing Asset at Fair Value, Amount [Roll Forward] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff Entity Address, State or Province Entity Address, State or Province Total, unrealized losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Nonaccrual Loans Financing Receivable, Excluding Accrued Interest, Nonaccrual PEO Total Compensation Amount PEO Total Compensation Amount Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year Common shares authorized, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Cash and cash equivalents: Cash and Cash Equivalents [Abstract] Beginning balance outstanding (in shares) Ending balance outstanding (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Notional Derivative, Notional Amount Basic (in shares) Weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Schedule of Aggregated by Portfolio Segment and Type of Modification Financing Receivable, Modified [Table Text Block] Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Residential construction Residential construction Construction Loans [Member] Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] ACL-Loans Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest, Purchase Accounting Adjustments Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest, Purchase Accounting Adjustments Interest-earning deposits Interest-Bearing Deposits in Banks and Other Financial Institutions Servicing rights asset, net Servicing Asset at Amortized Cost Total liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Liabilities With an Allowance Collateral Dependent Financing Receivable, With Related Allowance Collateral Dependent Financing Receivable, With Related Allowance Total noninterest income Noninterest Income Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss Fees and commissions Revenue from Contract with Customer, Including Assessed Tax Entity Address, City or Town Entity Address, City or Town Derivative fair value, net Derivative, Fair Value, Net Federal Home Loan Bank (“FHLB”) stock Federal Home Loan Bank Stock Restricted stock grant (in shares) Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Loans, Allowance for Credit Losses - Loans, and Credit Quality Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Receivables [Abstract] Receivables [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Title and Position [Domain] Title and Position [Domain] Purchase Price: Business Combination, Consideration Transferred [Abstract] Other assets held for sale Disposal Group, Including Discontinued Operation, Assets Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period General Basis of Accounting, Policy [Policy Text Block] Current year Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff Other intangibles Net book value Intangible Asset, Finite-Lived, after Accumulated Amortization Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Level 2 Fair Value, Inputs, Level 2 [Member] Accumulated amortization Intangible Asset, Finite-Lived, Accumulated Amortization Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] 90 Days & Over or nonaccrual Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Other intangibles Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Intangibles Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Intangibles Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Loans, net Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Recent Accounting Pronouncements Adopted and Future Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Provision for credit losses Provision for credit losses Total Credit Loss Expense (Reversal) Credit Loss Expense (Reversal) Liabilities Assumed: Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments, Liabilities [Abstract] Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments, Liabilities Uses of Estimates Use of Estimates, Policy [Policy Text Block] Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Long-term borrowings Total long-term borrowings Carrying Value Long-Term Debt Allowance for credit losses - loans (“ACL-Loans”) Less allowance for credit losses - Loans (“ACL-Loans”) Beginning balance Ending balance Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Year two Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Document Period End Date Document Period End Date Net cash provided by (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Net change in accrued interest payable and other liabilities Increase (Decrease) In Interest Payable and Other Liabilities The increase (decrease) during the reporting period in interest payable, which represents the amount owed to note holders, bond holders, and other parties for interest earned on loans or credit extended to the reporting entity and other operating liabilities. Preferred shares outstanding (in shares) Preferred Stock, Shares Outstanding Par Debt Instrument, Face Amount Revolving to Term Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan Deposits Deposits, Purchase Accounting Adjustments Deposits, Purchase Accounting Adjustments Security Exchange Name Security Exchange Name Gross losses Debt Securities, Available-for-Sale, Realized Loss Interest Rate Debt Instrument, Interest Rate, Effective Percentage Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Credit Loss Status [Domain] Credit Loss Status [Domain] Fair Value Debt Securities, Available-for-Sale, Maturity, Fair Value, Rolling Maturity [Abstract] Occupancy, equipment and office Occupancy Equipment and Office Expense This element represent Occupancy, Equipment And Office Expense. Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Accrued interest receivable and other assets Interest Receivable and Other Assets % of Total Loans Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 12 months or more, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer 2004 First Menasha Bancshares, Inc. First Menasha Bancshares Inc [Member] Represents information and name of acquiree. Segment Information Segment Reporting, Policy [Policy Text Block] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Due after five years through ten years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 5 through 10 Years, Amortized Cost Sale of servicing rights Sale of servicing rights Servicing Asset at Amortized Cost, Disposals Earnings per Common Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Earnings per common share: Earnings Per Share [Abstract] Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] ATBancorp Statutory Trust I ATBancorp Statutory Trust I [Member] ATBancorp Statutory Trust I Total liabilities Liabilities Trading Symbol Trading Symbol Securities available for sale (“AFS”), at fair value Estimated Fair Value Fair Value Securities AFS Debt Securities, Available-for-Sale, Excluding Accrued Interest Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward] Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Schedule of the Assets Acquired and Liabilities Assumed Including Purchase Price Allocation Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block] Company Selected Measure Name Company Selected Measure Name Unrealized gain / (loss) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Purchases of securities AFS Payments to Acquire Debt Securities, Available-for-Sale Deferred compensation plan asset market valuations Deferred Compensation Plan Asset Market Valuations Deferred Compensation Plan Asset Market Valuations Without an Allowance Collateral Dependent Financing Receivable, With No Related Allowance Collateral Dependent Financing Receivable, With No Related Allowance Lien Category [Axis] Lien Category [Axis] Deposits Interest Expense, Deposits Long-term borrowings Interest Expense, Long-Term Debt Acquisitions: Noncash Investing and Financing Items [Abstract] Purchases of other investments Payments to Acquire Other Investments Other liabilities held for sale (deposits) Other Liabilities, Held for Sale, Deposits, Fair Value Disclosure Other Liabilities, Held for Sale, Deposits, Fair Value Disclosure (Additions) / Reversals, net Valuation Allowance for Impairment of Recognized Servicing Assets, Additions (Deductions) for Expenses (Recoveries) Total assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assets Current year Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Securities AFS Debt Securities [Member] Asset Class [Domain] Asset Class [Domain] Cash Flows From Operating Activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Diluted (in shares) Diluted weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Asset at beginning of year Asset at end of year Servicing Asset At Amortized Cost, Before Valuation Allowance Servicing Asset At Amortized Cost, Before Valuation Allowance Net assets acquired Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Loans Total loans Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Underlying Security Market Price Change Underlying Security Market Price Change, Percent Retail & other Retail & other Retail and Other Financing Receivables [Member] Represents the financing receivables related to property that is used for retail and other purposes. Derivatives Derivative Instruments and Hedging Activities Disclosure [Text Block] U.S. Treasury securities US Treasury Securities [Member] Commitments to extend credit Commitments to Extend Credit [Member] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Short-term borrowings Short-Term Debt Unfunded commitments Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) Effect of dilutive common stock awards (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Schedule of Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Other intangibles Other Intangible Assets [Member] Variable Rate Component [Domain] Variable Rate Component [Domain] Variable Rate Component [Domain] Mortgage-backed securities Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Amortized Cost Card interchange income Credit and Debit Card [Member] Award Timing Predetermined Award Timing Predetermined [Flag] MidWestOne MidWestOne Financial Group, Inc. [Member] MidWestOne Financial Group, Inc. Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Variable Rate Component [Axis] Variable Rate Component [Axis] Variable Rate Component Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Total intrinsic value of options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Interest income: Interest and Dividend Income, Operating [Abstract] Comprehensive income: Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Stock-based compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Level 1 Fair Value, Inputs, Level 1 [Member] Residential junior mortgage Residential junior mortgage Junior Lien [Member] Capitalized mortgage servicing rights Servicing Asset at Fair Value, Additions Due after ten years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value ACL on acquired PSL loans Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Loan Purchased Other liabilities Other Liabilities, Purchase Accounting Adjustments Other Liabilities, Purchase Accounting Adjustments 2006 Baylake Corp. Baylake Corp [Member] Information of Baylake Corp. Gain on sale of loans held for sale, net Gain (Loss) on Sale of Financing Receivable Proceeds from sale of loans held for sale Proceeds from Sale, Loan, Held-for-Sale Year two Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff Collateral [Domain] Collateral Held [Domain] Beginning balance outstanding (in dollars per share) Ending balance outstanding (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value All Executive Categories All Executive Categories [Member] Purchase and retirement of common stock Stock Repurchased and Retired During Period, Value Interest rate lock commitments Interest Rate Lock Commitments [Member] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Investments securities pledged as collateral Restricted Investments Preferred shares authorized, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Long-term borrowings Long-Term Debt, Fair Value Plan Name [Domain] Plan Name [Domain] Allocated and single maturity date Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Beginning balance outstanding (in dollars per share) Ending balance outstanding (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Maturities / Paydowns Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Schedule of Carrying Value of other Investments Other Investments Not Readily Marketable [Table Text Block] Agricultural Agricultural [Member] Agricultural [Member] Data processing Information Technology and Data Processing Schedule of Basic and Diluted Earnings Per Common Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Deposits Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Schedule of Provision for Credit Losses Schedule of Provision for Credit Losses [Table Text Block] Schedule of Provision for Credit Losses Securities and Other Investments Investment in Debt and Equity Securities and Other Trading Assets [Text Block] Proceeds from calls and maturities of securities AFS Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Cash dividends paid on common stock Payments of Ordinary Dividends, Common Stock Expiration Date Trading Arrangement Expiration Date Schedule of Mortgage and Loan Servicing Rights Schedule Of Mortgage Servicing Rights [Table Text Block] Represents tabular disclosure related to mortgage servicing rights. Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Grade 5 Watch [Member] Represents the credits performing in accordance with the original terms, have adequate sources of repayment and little identifiable collectability risk. Liabilities: Liabilities Assumed: Liabilities [Abstract] Restricted cash and cash equivalents Restricted Cash and Cash Equivalent Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Loans Par value of PCD acquired loans at acquisition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financing Receivable, Excluding Accrued Interest, Before Allowance for Credit Loss Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financing Receivable, Excluding Accrued Interest, Before Allowance for Credit Loss ACL on acquired PCD loans Financing Receivable, Excluding Accrued Interest, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date Weighted average remaining life outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted-Average Remaining Contractual Term Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Subordinated notes Subordinated Debt [Member] Accrued interest on loans Financing Receivable, Accrued Interest, after Allowance for Credit Loss Proceeds from sale of MSRs Proceeds from Sale of Mortgage Servicing Rights (MSR) Accrued interest payable and other liabilities Other Liabilities Business Combination [Line Items] Business Combination [Line Items] Exercisable (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Common shares authorized (par value $0.01 per share) (in shares) Common Stock, Shares Authorized Interest-bearing deposits Interest-Bearing Deposit Liabilities Gross gains Debt Securities, Available-for-Sale, Realized Gain Goodwill Business Combination, Goodwill, Purchase Accounting Adjustments Business Combination, Goodwill, Purchase Accounting Adjustments LSR income, net Loan Servicing Right Income, Net Loan Servicing Right Income, Net Deposits Deposits, Fair Value Disclosure Unamortized premium /(discount) / debt issue costs Debt Instrument, Unamortized Discount (Premium), Net CRE investment Commercial Real Estate [Member] Exercise Price Award Exercise Price Cash Flows From Investing Activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Reccurring Recurring Fair Value, Recurring [Member] Wealth management fee income Investment Advisory, Management and Administrative Service [Member] Net income Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax Unrecognized compensation cost Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Document Quarterly Report Document Quarterly Report Net assets acquired Fair Value Of Assets Acquired, Net Fair Value Of Assets Acquired, Net Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Interest rate swaps Interest Rate Swap [Member] State, county and municipals US States and Political Subdivisions Debt Securities [Member] Grade 6 Special Mention [Member] Year three Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff Proceeds from sales of securities AFS Proceeds from sales of securities AFS Proceeds from Sale of Debt Securities, Available-for-Sale Percent of current loans Financing Receivable Recorded Investment Current Percentage Of Loan Represents the percentage of loans financing receivables that are current to total loans. Short and Long-Term Borrowings Debt Disclosure [Text Block] Accrued interest payable Interest Payable Interest Rate After Year Five Interest Rate After Year Five [Member] Interest Rate After Year Five Repayments of long-term borrowings Repayments of Long-Term Debt Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Business Combination [Table] Business Combination [Table] Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Loans, net Loans Receivable, Fair Value Disclosure Loans held for sale Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance Adoption Date Trading Arrangement Adoption Date Fixed interest rate Debt Instrument, Interest Rate, Stated Percentage Cash dividends on common stock Dividends, Common Stock, Cash Total stockholders’ equity Beginning balance Ending balance Equity, Attributable to Parent MSR asset Servicing Asset Other investments (equity securities) Equity Securities, FV-NI, Current Assets Assets Acquired: Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Payment Delay Payment Deferral [Member] Number of common stock issued for consideration (in shares) Nicolet common stock issued (in shares) Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares Other investments Total other investments Other Investments Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Schedule of Loans by Risk Categories and Gross Charge-offs Financing Receivable Credit Quality Indicators [Table Text Block] RPAs - participated in contracts RPAs - participated in contracts [Member] RPAs - participated in contracts Measured at Fair Value on a Nonrecurring Basis Fair Value, Nonrecurring [Member] Insider Trading Policies and Procedures [Line Items] Beginning balance outstanding (in shares) Ending balance outstanding (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Taxable Interest Income, Securities, Operating, Taxable Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Commercial Commercial Portfolio Segment [Member] Loans Collateral Dependent Financing Receivable, Unpaid Principal Balance Collateral Dependent Financing Receivable, Unpaid Principal Balance Investment securities Investments, Purchase Accounting Adjustments Investments, Purchase Accounting Adjustments Performance-Based Restricted Stock Units Phantom Share Units (PSUs) [Member] Schedule of Junior Subordinated Debentures and Subordinated Notes Schedule Of Junior Subordinated Debentures [Table Text Block] It represents junior subordinated debentures. Commercial real estate Commercial Real Estate Portfolio Segment [Member] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Business Combination [Domain] Business Combination [Domain] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Shares excluded from calculation of earnings per common share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Goodwill Goodwill [Table Text Block] Entity Central Index Key Entity Central Index Key Common stock Common Stock, Value, Outstanding Net interest income after provision for credit losses Interest Income (Expense), after Provision for Loan Loss All Adjustments to Compensation All Adjustments to Compensation [Member] Core deposit intangibles Core Deposits [Member] Business Combination [Axis] Business Combination [Axis] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Net cash provided by (used in) operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Net (increase) decrease in other real estate and other assets Payments For (Proceeds From) Other Real Estate And Other Assets Payments For (Proceeds From) Other Real Estate And Other Assets Residential Residential Portfolio Segment [Member] Other liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Servicing rights asset Mortgage Servicing Rights [Member] Represents details of mortgage servicing rights . Grade 7 Substandard [Member] Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Residential first mortgage Residential first mortgage First Lien [Member] Represents information related to First Lien. Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Schedule of Other Intangible Assets Intangible Asset, Finite-Lived [Table Text Block] Diluted earnings per common share (in dollars per share) Business Combination, Pro Forma Information, Pro Forma Earnings Per Share, Diluted Floating interest rate basis spread Debt Instrument, Basis Spread on Variable Rate Option Shares Outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Servicing rights acquired Servicing Asset at Amortized Cost, Acquired Servicing Rights Servicing Asset at Amortized Cost, Acquired Servicing Rights City Area Code City Area Code Restricted Stock Total Restricted Stock Restricted Stock [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Percent of total loans Percentage Of Loans By Past Due Status Represents the percentage of loan by past due status. Name Forgone Recovery, Individual Name Level 3 Fair Value Measurements: Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Remaining vesting period over which cost expected to be recognized Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Proceeds from sales of other investments Proceeds from Sale of Other Investments Value of Nicolet common stock consideration Value of Nicolet common stock consideration Business Combination, Consideration Transferred, Equity Interest Statement [Line Items] Statement [Line Items] Total assets Assets Entity [Domain] Entity [Domain] Trust preferred securities qualify as Tier 1 capital Trust Preferred Securities Qualify As Tier1 Capital It represents amount of trust preferred securities qualify as Tier 1 capital. Term Extension Extended Maturity [Member] BOLI Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Bank Owned Life Insurance Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Bank Owned Life Insurance Total interest expense Interest Expense, Operating Accrued interest on investment securities Debt Securities, Available-for-Sale and Held-to-maturity, Accrued Interest Debt Securities, Available-for-Sale and Held-to-maturity, Accrued Interest Preferred shares issued (in shares) Preferred Stock, Shares Issued Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Investment securities: Interest and Dividend Income, Securities, by Taxable Status [Abstract] Total interest income Interest and Dividend Income, Operating Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] As % of ACL-Loans Financing Receivable, Excluding Accrued Interest, Allowance For Credit Loss, To Total, Percent Represents percentage of allowance for credit losses. Net realized (gains) losses included in income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Equity securities with readily determinable fair values Equity Securities without Readily Determinable Fair Value, Amount Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax 2005 Mid-Wisconsin Financial Services, Inc. Mid Wisconsin Financial Services Inc [Member] Represents information about Mid Wisconsin Financial Services Inc. Total liabilities Business Combination, Recognized Liability Assumed, Liability Stock-Based Compensation Share-Based Payment Arrangement [Text Block] Mortgage-backed securities Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Fair Value PEO PEO [Member] Amortization during the period Amortization of Mortgage Servicing Rights (MSRs) Noninterest-bearing demand deposits Noninterest-Bearing Deposit Liabilities Net increase (decrease) in deposits Increase (Decrease) in Deposits Other assets held for sale (loans) Other Assets, Loans, Held-for-Sale, Fair Value Disclosure Other Assets, Loans, Held-for-Sale, Fair Value Disclosure Stock based compensation expense Share-Based Payment Arrangement, Expense Measurement Basis [Axis] Measurement Basis [Axis] Goodwill Goodwill Goodwill at beginning of year Goodwill at end of period Goodwill Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Total, number of securities Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions Exercise of stock options (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Goodwill Acquisition Goodwill, Acquired During Period Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Net unrealized holding gains (losses) OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Fair value of assets acquired Fair Value of Assets Acquired Retained Earnings Retained Earnings [Member] Revolving Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff Forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Cash and cash equivalents Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Corporate debt securities Corporate Debt Securities [Member] Diluted (in dollars per share) Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted Entity Current Reporting Status Entity Current Reporting Status Net cash provided by (used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] FDIC assessments Federal Deposit Insurance Corporation Premium Expense Total Shareholder Return Amount Total Shareholder Return Amount Mortgage income, net Fees and Commissions, Mortgage Banking and Servicing Intangibles amortization Amortization during the period Intangible Asset, Finite-Lived, Amortization Expense Intangible Asset, Finite-Lived [Line Items] Intangible Asset, Finite-Lived [Line Items] Year three Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year Schedule of Unaudited Pro Forma Business Combination, Pro Forma Information [Table Text Block] Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Total assets Business Combination, Recognized Asset Acquired, Asset Additions during the period Intangible Asset, Finite-Lived, Acquired % of Total Percentage Of Non Accrual Loan Percentage of non accrual loan under each category. Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Cash Flows From Financing Activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Premises and equipment, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Other interest income Other Interest and Dividend Income Financial Instruments [Domain] Financial Instruments [Domain] Financial assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Year four Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Derivative assets Assets Derivative Asset Purchase of stock in stock-based compensation plans Stock Repurchased During Period, Value Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Goodwill and Other Intangibles and Servicing Rights Intangible Asset and Goodwill [Text Block] Underlying Securities Award Underlying Securities Amount Estimated Fair Value Estimate of Fair Value Measurement [Member] Issuance of common stock Stock Issued During Period, Value, New Issues Transfer out Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Term Extension & Interest Rate Reduction Extended Maturity and Interest Rate Reduction [Member] Service charges on deposit accounts Deposit Account [Member] Forfeited (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Due in one year through five years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost Residential mortgage loans and agricultural loans serviced for others Residential Mortgage Loans Serviced For Others Represents information of Residential mortgage loans serviced for others. Schedule of Restricted Stock Activity Nonvested Restricted Stock Shares Activity [Table Text Block] Number of shares were available for grant (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Total Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount Construction & land development Construction & land development Construction and Land Development [Member] Represents the financing receivables related to property that is used for construction and land development. Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other liabilities Other noninterest income Noninterest Income, Other Reserve for unfunded commitments Off-Balance-Sheet, Credit Loss, Liability Title and Position [Axis] Title and Position [Axis] Provision for credit losses - loans Loans Provision for Other Credit Losses Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Less than 12 months, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Current Fiscal Year End Date Current Fiscal Year End Date Collateral dependent loans Collateral Dependent Loans [Member] Collateral Dependent Loans Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Loans Insured or Guaranteed by Government Authorities [Domain] Loans Insured or Guaranteed by Government Authorities [Domain] Provision for credit losses Financing Receivable, Excluding Accrued Interest, Credit Loss Expense (Reversal) Derivative [Line Items] Derivative [Line Items] Acquisitions and Divestitures Business Combination [Text Block] Collateral [Axis] Collateral Held [Axis] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Cash dividends on common stock (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Due in less than one year Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Issuance of stock in stock-based compensation plans Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Thereafter Intangible Asset, Finite-Lived, Estimated Amortization Expense, after Year Five Schedule of Amortized Cost and Fair Value of Investment Securities by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] Other investments (equity securities) Equity Securities [Member] Revolving Financing Receivable, Excluding Accrued Interest, Revolving Schedule of Stock Options Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Securities AFS: Debt Securities, Available-for-Sale, Realized Gain (Loss) [Abstract] Schedule of Allowance for Credit Losses Financing Receivable, Allowance for Credit Loss [Table Text Block] Common shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Balance at beginning of year Balance at end of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Proceeds from issuance of common stock in stock-based compensation plans Proceeds from Stock Options Exercised, Net Proceeds from Stock Options Exercised, Net Interest Rate For The Years One Through 5 Interest Rate For The Years One Through FIve [Member] Interest Rate For The Years One Through FIve Owner-occupied commercial real estate (“CRE”) Owner-occupied CRE Commercial Real Estate Owner Occupied [Member] Represents the financing receivables related to property that is owner occupied and used for residential purpose. County Bancorp Statutory Trust III County Bancorp Statutory Trust III [Member] County Bancorp Statutory Trust III Forward Contracts Forward Contracts [Member] Purchases of common stock in stock-based compensation plans Payments For Stock Options Exercised Payments For Stock Options Exercised Tax-exempt Interest Income, Securities, Operating, Tax Exempt Fox River Valley Capital Trust Fox River Valley Capital Trust [Member] Fox River Valley Capital Trust 12 months or more, unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Equity Components [Axis] Equity Components [Axis] Product and Service [Domain] Product and Service [Domain] Remaining principal balance Servicing Asset, Other Remaining Principal Balance, Acquisition Servicing Asset, Other Remaining Principal Balance, Acquisition Entity Interactive Data Current Entity Interactive Data Current Noninterest expense: Noninterest Expense [Abstract] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Termination Date Trading Arrangement Termination Date Shares surrendered to satisfy exercise price and/or tax withholding requirements (in shares) Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Fair value of liabilities assumed Liabilities Assumed Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Net interest income Interest Income (Expense), Operating MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Document Type Document Type Net cash (paid) received in business combination Payments to Acquire Businesses, Net of Cash Acquired Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Loss on early extinguishment of debt Gain (Loss) on Extinguishment of Debt Fair Value as of Grant Date Award Grant Date Fair Value Allowance for credit losses on securities AFS Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest Schedule of Unrealized Losses and Fair Value of Investment Securities Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Aggregate intrinsic value exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name BOLI Bank Owned Life Insurance, Purchase Accounting Adjustments Bank Owned Life Insurance, Purchase Accounting Adjustments Less than 12 months, unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Allowance Allocation Collateral Dependent Financing Receivable, Related Allowance Collateral Dependent Financing Receivable, Related Allowance Allowance for credit losses - loans to loans (in percent) Percentage Of Allowance For Credit Losses To Loans Represents percentage of Allowance for credit losses to loans. Income before income tax expense Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Financial standby letters of credit Financial Standby Letter of Credit [Member] Gross carrying amount Intangible Asset, Finite-Lived, before Accumulated Amortization Unrealized gains (losses) on securities AFS: OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax [Abstract] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four LSR asset Loan Servicing Rights [Member] Loan Servicing Rights Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Other investments Other Investments and Securities, at Cost Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Allocated and single maturity date Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value Income tax (expense) benefit Other Comprehensive Income (Loss), Tax Goodwill: Goodwill [Roll Forward] Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Other Commitments [Table] Other Commitments [Table] Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Weighted average remaining life exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted-Average Remaining Contractual Term Central Bancshares Capital Trust II Central Bancshares Capital Trust II [Member] Central Bancshares Capital Trust II Award Type [Domain] Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Fair Value Measurements Fair Value Disclosures [Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] U.S. government agency securities US Government Agencies Debt Securities [Member] Supplemental Disclosures of Cash Flow Information: Supplemental Cash Flow Information [Abstract] 2027 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One Closing stock price (in dollars per share) Share Price PEO Name PEO Name Financial liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Cash paid for taxes Income Tax Paid, before Refund Received Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Rolling Maturity [Abstract] Cash and due from banks Cash and Due from Banks Legal Entity [Axis] Legal Entity [Axis] Schedule of Past Due Loans by Portfolio Segment Financing Receivable, Past Due [Table Text Block] Current Financial Asset, Not Past Due [Member] Other Commitments [Line Items] Other Commitments [Line Items] Stock based compensation tax benefit Share-Based Payment Arrangement, Expense, Tax Benefit Credit Loss Status [Axis] Credit Loss Status [Axis] Noninterest income: Noninterest Income [Abstract] Exercise of stock options (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Schedule of the Contract or Notional Amount of Exposure to Off-balance-sheet Risk Fair Value, Concentration of Risk [Table Text Block] Cash and cash equivalents Beginning Ending Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Customer list intangibles Customer Lists [Member] Schedule of Finite-Lived Intangible Assets [Table] Intangible Asset, Finite-Lived [Table] Cash and cash equivalents Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash And Cash Equivalents Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash And Cash Equivalents Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code BOLI income Bank Owned Life Insurance Income Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] ACL-Loans Financing Receivable, Allowance for Credit Loss [Roll Forward] Measurement Frequency [Domain] Measurement Frequency [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Interest expense: Interest Expense, Operating and Nonoperating [Abstract] 2028 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Two Personnel Labor and Related Expense Due after ten years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost Allowance for Credit Losses - Loans Credit Loss, Financial Instrument [Policy Text Block] Net (increase) decrease in loans Payments for (Proceeds from) Loans and Leases Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Schedule of Derivative Asset and Liability Balances Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Basic (in dollars per share) Basic earnings per common share (in dollars per share) Earnings Per Share, Basic Purchase and retirement of common stock Payments for Repurchase of Common Stock Mortgage-backed securities Collateralized Mortgage-Backed Securities [Member] Insider Trading Arrangements [Line Items] Stock Incentive Plan Stock Incentive Plan [Member] This element represents stock incentive plan. Loans Financing Receivable, Excluding Accrued Interest, Before Allowance for Credit Loss, Purchase Accounting Adjustments Financing Receivable, Excluding Accrued Interest, Before Allowance for Credit Loss, Purchase Accounting Adjustments Award Type [Axis] Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Real Estate Real Estate [Member] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss Retained earnings Retained Earnings (Accumulated Deficit) Bank owned life insurance (“BOLI”) Bank Owned Life Insurance Product and Service [Axis] Product and Service [Axis] Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Stock Common Stock [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Recoveries Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Year four Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff Cover [Abstract] Reclassifications Reclassification, Comparability Adjustment [Policy Text Block] Derivative Contract [Domain] Derivative Contract [Domain] Year one Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff Other Business Assets Other Business Assets [Member] Other Business Assets [Member] Fair Value Adjustments Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract] Equity Awards Adjustments Equity Awards Adjustments [Member] Gains (losses) on sales of securities AFS, net Debt Securities, Available-for-Sale, Realized Gain (Loss) Total liabilities and stockholders’ equity Liabilities and Equity Goodwill and other intangibles, net Goodwill and other intangibles, net Intangible Asset, Including Goodwill, after Accumulated Amortization Business development and marketing Business Development Purchases (acquired with MidWestOne) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Stock Options Stock Options Share-Based Payment Arrangement, Option [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Asset Class [Axis] Asset Class [Axis] Revolving to Term Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan, Writeoff Grades 1-4 Pass [Member] Plan Name [Axis] Plan Name [Axis] Schedule of Loan Composition Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Tabular List, Table Tabular List [Table Text Block] Additional paid-in capital Additional Paid in Capital 2031 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Five 2029 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Three 2026 (remaining six months) Intangible Asset, Finite-Lived, Estimated Amortization Expense, Remainder of Fiscal Year Name Awards Close in Time to MNPI Disclosures, Individual Name Stockholders’ Equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Aggregate intrinsic value outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Commercial & industrial Commercial and Industrial Financing Receivables [Member] Represents financing receivables related to commercial and industrial loans. Asset gains (losses), net Asset (gains) losses, net Gain (Loss) on Disposition of Assets for Financial Service Operations Due in one year through five years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Schedule of Proceeds and Realized Gains or Losses from the Sale of AFS and HTM Securities Schedule of Realized Gain (Loss) [Table Text Block] Transfer of loans and bank premises to other real estate owned Real Estate Owned, Transfer to Real Estate Owned Preferred shares authorized (no par value) (in shares) Preferred Stock, Shares Authorized Time-Based Restricted Stock Awards Time-Based Restricted Stock Awards [Member] Time-Based Restricted Stock Awards Significant Accounting Policies Update Significant Accounting Policies Update [Policy Text Block] Significant Accounting Policies Update Adjustment to Compensation: Adjustment to Compensation [Axis] Other investments, including equity securities Other Investment Fair Value Disclosure This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Investments which are not defined as or included in marketable (debt, equity, or other) securities whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet. Hedging Designation [Domain] Hedging Designation [Domain] Percent past due Financing Receivable, Percent Past Due Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activity Net (increase) decrease in premises and equipment Payments to Acquire Productive Assets Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Hedging Designation [Axis] Hedging Designation [Axis] MidWestOne Statutory Trust II MidWestOne Statutory Trust II [Member] MidWestOne Statutory Trust II Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Assets, fair value disclosure Assets, Fair Value Disclosure Borrowings Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Long-term And Short-Term Debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Long-term And Short-Term Debt Valuation Allowance: Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward] Name Measure Name Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Contract and notional amounts of commitments Fair Value Disclosure, off-Balance-Sheet Risks, Amount, Liability Debt Instrument [Line Items] Debt Instrument Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Loans Insured or Guaranteed by Government Authorities [Axis] Loans Insured or Guaranteed by Government Authorities [Axis] Loans, including loan fees Interest and Fee Income, Financing Receivable Additional Paid-In Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Total, fair value Debt Securities, Available-for-Sale, Unrealized Loss Position Director Director [Member] Other intangibles Business Combination, Recognized Asset Acquired, Identifiable Other Intangible Asset, Excluding Goodwill Business Combination, Recognized Asset Acquired, Identifiable Other Intangible Asset, Excluding Goodwill Accrued interest receivable Interest Receivable Due in less than one year Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost Name Trading Arrangement, Individual Name Charge-offs Valuation Allowance for Impairment of Recognized Servicing Assets, Deductions for Aggregate Write-Downs Company Selected Measure Amount Company Selected Measure Amount Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Investments, Debt and Equity Securities [Abstract] 30-89 Days Past Due (accruing) Financial Asset, 30 To 89 Days Past Due [Member] Financing receivables that are more than 30 days past due but fewer than 89 days past due. Assets Acquired: Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments, Assets [Abstract] Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments, Assets Barron Ivestment Capital Trust I Barron Ivestment Capital Trust I [Member] Barron Ivestment Capital Trust I Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts and Financing Receivables [Table] RPAs - participated out contracts RPAs - participated out contracts [Member] RPAs - participated out contracts Increase in cash surrender value of life insurance Life Insurance, Corporate or Bank Owned, Change in Value Derivative liabilities Liabilities Derivative Liability Total revenue, net of interest expense Business Combination, Pro Forma Information, Pro Forma Revenue Non-PEO NEO Non-PEO NEO [Member] Entity Address, Address Line One Entity Address, Address Line One Lien Category [Domain] Lien Category [Domain] Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Purchase price of PCD loans at acquisition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financing Receivable, Excluding Accrued Interest, After Allowance for Credit Loss Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financing Receivable, Excluding Accrued Interest, After Allowance for Credit Loss Income tax expense Income Tax Expense (Benefit) Total noninterest expense Noninterest Expense Award Timing Method Award Timing Method [Text Block] Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Subordinated Notes due 2031 Subordinated Notes Due 2031 [Member] Subordinated Notes Due 2031 Charge-offs TOTAL Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Net income Net income Net income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] County Bancorp Statutory Trust II County Bancorp Statutory Trust II [Member] County Bancorp Statutory Trust II Statement [Table] Statement [Table] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Restatement Determination Date: Restatement Determination Date [Axis] Net change in accrued interest receivable and other assets Increase (Decrease) In Accrued Interest Receivable And Other Assets The increase (decrease) during the reporting period in accrued interest receivable and other assets. Schedule of Collateral Dependent Loans by Portfolio Segment Collateral Dependent Financing Receivables [Table Text Block] Collateral Dependent Financing Receivables [Table Text Block] Year one Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year Schedule of Nonaccrual Loans by Portfolio Segment Financing Receivable, Nonaccrual [Table Text Block] Exercisable (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Derivative Instruments and Hedging Activities Disclosures [Line Items] Derivative Instruments and Hedging Activities Disclosures [Line Items] Loans held for sale Loan, Held-for-Sale, Fair Value Disclosure Premises and equipment Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] ACL-Loans Credit and interest rate mark on PCD loans at acquisition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Other assets Other Assets, Purchase Accounting Adjustments Other Assets, Purchase Accounting Adjustments Borrowings Debt, Long-term and Short-Term, Combined Amount, Purchase Accounting Adjustments Debt, Long-term and Short-Term, Combined Amount, Purchase Accounting Adjustments Basis of Presentation Basis of Presentation and Significant Accounting Policies [Text Block] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract]