Amendment Flag Current Fiscal Year End Date Document Period End Date Entity [Domain] Entity [Domain] Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Registrant Name Entity Central Index Key Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Legal Entity [Axis] Legal Entity [Axis] Document Type Entity Shell Company Entity Emerging Growth Company Entity Ex Transition Period Entity Small Business Changes in AOCL [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Award Type [Axis] Number of securities with market fair value less than amortized cost ACCOUNTING POLICIES [Abstract] ASU 2016-02 [Member] Accounting Standards Update 2016-02 [Member] ASU 2017-08 [Member] Accounting Standards Update 2017-08 [Member] ASU 2014-09 [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accretion of discount on subordinated debentures Accretion Expense Unrealized Gains (Losses) on Cash Flow Hedges [Member] Unrealized Losses on Securities Available For Sale [Member] Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] OTTI recognized in accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Loss [Member] Accumulated other comprehensive loss Accumulated other comprehensive loss for regulatory purposes Accumulated Other Comprehensive Income (Loss), Net of Tax ACCUMULATED OTHER COMPREHENSIVE LOSS [Abstract] Expected residual value of core deposit intangible asset Weighted average amortization period of core deposit intangible asset Share based compensation withholding obligation Adjustments Related to Tax Withholding for Share-based Compensation Total Adjustments Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities ADJUSTMENTS TO RECONCILE NET INCOME TO NET CASH FROM OPERATING ACTIVITIES ADJUSTMENTS TO RECONCILE NET INCOME TO NET CASH FROM OPERATING ACTIVITIES Adjustments for New Accounting Pronouncements [Axis] Total FHLB advances, Amount Advances from the FHLB Advertising Total compensation expense recognized Allocated Share-based Compensation Expense Increase (decrease) in allowance for loan losses Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment Amortization Amortization of Mortgage Servicing Rights (MSRs) Intangible amortization expense Amortization of Intangible Assets Antidilutive Securities [Axis] Antidilutive shares excluded from computation of diluted loss per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities, Name [Domain] Other real estate, additional charge Other Asset Backed [Member] Impairment charges recognized [Abstract] Assets [Abstract] Assets, Fair Value Disclosure [Abstract] ASSETS ASSETS [Abstract] Assets [Abstract] Total Assets Assets Securities available for sale Securities available for sale Unrealized gains Unrealized losses Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Available-for-sale Securities, Amortized Cost Basis [Abstract] Total available-for-sale securities fair value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value Amortized cost Debt Securities, Available-for-sale, Amortized Cost Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] Maturing after five years but within ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Maturing within one year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract] Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract] Maturing after ten years Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost Maturing after ten years Maturing after five years but within ten years U.S. agency residential mortgage backed Maturing after one year but within five years Fair value Total Debt Securities, Available-for-sale Maturing after one year but within five years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost U.S. agency residential mortgage-backed Maturing within one year Gain and losses realized on sale of securities available for sale [Abstract] Balance Sheet Location [Domain] Balance Sheet Location [Axis] Bank owned life insurance Bank owned life insurance Bank-owned life insurance REGULATORY MATTERS [Abstract] Buildings [Member] Building [Member] Total assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Cash and cash equivalents Total liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Business Acquisition [Line Items] Business Acquisition, Acquiree [Domain] Equity issued under merger agreement (in shares) Business Acquisition [Axis] RECENT ACQUISITION [Abstract] RECENT ACQUISITION Business Combination Disclosure [Text Block] Net assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Recent Acquisition [Abstract] Business Combination, Description [Abstract] Property and equipment, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Valuation of the assets acquired and liabilities assumed [Abstract] Merger related expenses Non-interest expense amount Purchase price (fair value of consideration) Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Under Legacy GAAP [Member] Total capital to risk-weighted assets [Abstract] Total risk-based capital Capital Actual, Ratio Capital to Risk Weighted Assets Minimum for Well-Capitalized Institutions, Ratio Minimum for Adequately Capitalized Institutions, Amount Minimum for Well Capitalized Institutions, Amount Minimum for Adequately Capitalized Institutions, Ratio Recorded Book Balance [Member] Reported Value Measurement [Member] STATEMENTS OF CASH FLOWS Information Regarding Options Exercised Net Increase (Decrease) in Cash and Cash Equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash received in the acquisition of TCSB Bancorp Inc. Acquisition of business, less cash received Cash and Cash Equivalents at Beginning of Year Cash and Cash Equivalents at End of Year Cash and Cash Equivalents Cash and Cash Equivalents, at Carrying Value Cash and due from banks Unrealized gain on cash flow hedges, net of tax Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Cash Flow Hedge Designation [Member] Cash Flow Hedging [Member] Non accretable difference Certain Loans Acquired in Transfer, Nonaccretable Difference Accretable yield Certain Loans Acquired in Transfer, Accretable Yield Purchase Credit Impaired (PCI) Loans Reclassification from (to) nonaccretable difference Fair value of acquired loans at acquisition Accretion of income Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion Balance at end of period Balance at beginning of period Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield New loans purchased Disposals/other adjustments Accretable yield of PCI loans, or income expected to be collected [Roll Forward] Carrying amount, net of allowance for loan losses Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net Loans acquired with deteriorated credit quality Total carrying amount Allowance for loan losses Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses Contractually required payments Cash flows expected to be collected at acquisition Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition Class of Stock [Line Items] Stock Reserved [Line Items] Commercial [Member] Commercial [Member] Commercial and Industrial [Member] Commercial and Industrial [Member] U.S. Agency Commercial Mortgage-Backed [Member] COMMITMENTS AND CONTINGENT LIABILITIES Commitments and Contingencies Disclosure [Text Block] Commitments to Extend Credit [Member] COMMITMENTS AND CONTINGENT LIABILITIES [Abstract] Commitments and contingent liabilities Common Stock [Member] Common Stock Subject to Mandatory Redemption [Member] Common stock, shares authorized (in shares) Declared (in dollars per share) Common Stock [Abstract] Common stock, par value (in dollars per share) Actual, Amount Common equity tier 1 capital Common Equity Tier One Capital Common stock reserved for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Minimum for Well-Capitalized Institutions, Amount Common Equity Tier One Capital Required to be Well-Capitalized Minimum for Adequately Capitalized Institutions, Amount Common Equity Tier One Capital Required for Capital Adequacy Common equity tier 1 capital to risk-weighted assets [Abstract] Common Equity Tier One Capital [Abstract] Common stock, shares issued (in shares) Common stock, shares outstanding (in shares) Common stock, no par value, 500,000,000 shares authorized; issued and outstanding: 23,579,725 shares at December 31, 2018 and 21,333,869 shares at December 31, 2017 Common Stock, Value, Issued Communications Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Components of deferred tax assets and liabilities [Abstract] ACCUMULATED OTHER COMPREHENSIVE LOSS Comprehensive Income (Loss) Note [Text Block] Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent COMPREHENSIVE INCOME CONCENTRATIONS OF CREDIT RISK Concentration Risk Disclosure [Text Block] Concentration Risk Type [Domain] Concentration Risk Type [Axis] Concentration Risk [Line Items] Concentration Risk [Table] INDEPENDENT BANK CORPORATION (PARENT COMPANY ONLY) FINANCIAL INFORMATION Condensed Financial Information of Parent Company Only Disclosure [Text Block] Consolidated [Member] Consolidated Entities [Member] PRINCIPLES OF CONSOLIDATION Construction [Member] Retail [Member] Consumer [Member] Contract liabilities Contract assets Core Deposits [Member] Corporate [Member] Credit Loss Status [Domain] Credit Loss Status [Axis] Cumulative effect of change in accounting Cumulative effect of change in accounting Current expense Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Table] Disaggregation of Revenue Sources by Attributes [Abstract] Disaggregation of Revenue Sources by Attribute Designated as Hedging Instrument [Member] Twelve Months or More, Unrealized Losses Less Than Twelve Months, Fair Value Debt Securities, Available-for-sale [Table] Losses Realized gains Twelve Months or More, Fair Value Less Than Twelve Months, Unrealized Losses Total, Fair value Debt Securities, Available-for-sale, Unrealized Loss Position Total, Unrealized Losses Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Net gains on securities Debt and Equity Securities, Realized Gain (Loss) OTHER BORROWINGS [Abstract] 2018 [Member] Debt Instrument, Redemption, Period One [Member] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Axis] Interest Rate Issue Date Debt Instrument, Issuance Date Interest Rate Spread Debt Instrument, Basis Spread on Variable Rate 2017 [Member] Debt Instrument, Redemption, Period Two [Member] Trust Preferred Securities Issued Debt Instrument, Face Amount OTHER BORROWINGS Debt Disclosure [Text Block] Discount Debt Instrument, Unamortized Discount Maturity Date Property and equipment Deferred Tax Assets, Property, Plant and Equipment Unrealized loss on securities available for sale Deferred expense Gross deferred tax liabilities Deferred Tax Liabilities, Gross Deferred tax assets, net Deferred tax assets, net Deferred Tax Assets, Net Deferred tax assets [Abstract] Gross deferred tax assets Deferred Tax Assets, Gross Other Deferred Tax Assets, Other Loss carryforwards Share based payments Allowance for loan losses Litigation settlement Deferred compensation Alternative minimum tax credit carry forward Unrealized loss on trading securities Deferred tax liabilities [Abstract] Unrealized gain on derivative financial instruments Deferred Tax Liabilities, Derivatives Maximum contribution of employees' eligible wages Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent Maximum matching contribution, percent Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 401(k) and employee stock ownership plans amount expensed Defined Contribution Plan, Cost DEPOSITS Deposit Liabilities Disclosures [Text Block] Total Deposits Deposits Savings and interest-bearing checking Deposits DEPOSITS [Abstract] Depreciation expense Net depreciation, amortization of intangible assets and premiums and accretion of discounts on securities, loans and interest bearing deposits - time Depreciation, Amortization and Accretion, Net Average Maturity Derivatives Derivative financial instruments DERIVATIVE FINANCIAL INSTRUMENTS Derivative Instruments and Hedging Activities Disclosure [Text Block] Derivative financial instrument according to type of hedge [Abstract] Derivative Instrument [Axis] Derivative Instrument [Axis] DERIVATIVE FINANCIAL INSTRUMENTS [Abstract] Notional Amount Derivatives Derivative financial instruments Derivative Liability Asset Derivatives Derivative Asset, Fair Value, Gross Asset Fair value of derivative instruments, balance sheet location [Abstract] Gain (Loss) Recognized in Income Fair Value Liability Derivatives Derivative Instruments, Gain (Loss) [Table] Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Hedging Relationship [Axis] Derivative Instruments, Gain (Loss) [Line Items] Derivative Contract [Domain] DERIVATIVE FINANCIAL INSTRUMENTS Derivatives, Fair Value [Line Items] Carrying amount of loans that meet the criteria of ASC 310-30 treatment [Abstract] Impact [Member] Director [Member] SHARE BASED COMPENSATION AND BENEFIT PLANS [Abstract] SHARE BASED COMPENSATION AND BENEFIT PLANS Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Cash dividends declared Dividends, Common Stock, Cash Earnings Per Share Reconciliation [Abstract] Basic (in dollars per share) Earnings Per Share, Basic NET INCOME PER COMMON SHARE Earnings Per Share, Policy [Policy Text Block] Diluted (in dollars per share) Earnings Per Share, Diluted Net income per common share Statutory federal income tax rate Total compensation cost not yet recognized, period for recognition Stock Options [Member] Tax benefit relating to compensation expense recognized Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Tax benefit realized Total compensation cost not yet recognized Furniture, fixtures and equipment Equipment Expense Equipment [Member] Equity securities at fair value, net gains (losses) Equity Securities, FV-NI, Unrealized Gain (Loss) Equity Component [Domain] Equity securities at fair value Equity Securities, FV-NI VISA Class B Shares [Member] Equity Securities [Member] Custodial deposit accounts Escrow Deposit Fair Value [Member] Estimate of Fair Value Measurement [Member] Executive Officers [Member] Estimated fair value of intangible assets Included in other comprehensive income (loss) Asset (Liability) Fair Value [Abstract] Included in results of operations Amount of total losses for the period included in earnings attributable to the change in unrealized losses relating to assets and liabilities still held at December 31 Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Measurements, Recurring and Nonrecurring [Table] FAIR VALUE DISCLOSURES [Abstract] Measurement Basis [Axis] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Measurement Frequency [Axis] Quantitative Information About Level 3 Fair Value Measurements Measured on a Recurring Basis and Non-recurring Basis Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Changes in fair value for financial assets [Abstract] Assets and liabilities measured at fair value [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] Fair Value, Hierarchy and NAV [Axis] Fair Value, Hierarchy [Axis] Fair Value Measurement Inputs and Valuation Techniques [Table] Assets and Liabilities Measured at Fair Value Quantitative information about Level 3 fair value measurement measured on a non recurring basis [Abstract] Liability Class [Axis] Recurring Basis [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Measurement Frequency [Domain] Nonrecurring Basis [Member] Fair Value, Measurements, Nonrecurring [Member] Fair Value by Liability Class [Domain] Fair Value Hierarchy and NAV [Domain] FAIR VALUE DISCLOSURES Fair Value Disclosures [Text Block] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Estimated Fair Values and Recorded Book Balances Fair Value, by Balance Sheet Grouping [Table Text Block] Reconciliation for all Assets and (Liabilities) Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, by Balance Sheet Grouping [Table] Concentration of Risk [Abstract] Fair Value Measurement [Domain] Concentration of risk loans receivable Significant Unobservable Inputs (Level 3) [Member] Significant Unobservable Inputs, (Level 3) [Member] Fair Value, Inputs, Level 3 [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member] Significant Other Observable Inputs (Level 2) [Member] Significant Other Observable Inputs, (Level 2) [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Purchases, issuances, settlements, maturities and calls Ending balance Beginning balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Transfers in and/or out of Level 3 Difference Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Value, Option, Quantitative Disclosures [Table] Fair Value, Option, Quantitative Disclosures [Line Items] Changes in Fair Value for Financial Assets Federal Home Loan Bank and Federal Reserve Bank stock, at cost Federal Home Loan Bank and Federal Reserve Bank Stock Federal Home Loan Bank Stock and Federal Reserve Bank Stock FHLB advances terminated Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Repayment and Penalties Federal Home Loan Banks [Abstract] FDIC deposit insurance 2018, Amount Federal home loan bank stock Advances from Federal Home Loan Bank ("FHLB") [Member] Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] Federal funds purchased Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract] Total fixed-rate advances, amount Federal Home Loan Bank, Advances, Maturities Summary, Fixed Rate Variable-rate advances - 2018, amount Unused borrowing capacity with FHLB Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due [Abstract] 2022, Amount 2022, Rate 2019, Rate 2020, Rate Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Two to Three Years from Balance Sheet Date 2019, Amount 2018, Rate Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due within One Year of Balance Sheet Date Federal Reserve Bank Advances [Member] Federal Reserve Bank Advances [Member] 2020, Amount Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Three LOANS HELD FOR SALE Finance, Loan and Lease Receivables, Held-for-sale, Policy [Policy Text Block] FAIR VALUES OF FINANCIAL INSTRUMENTS Financial Instruments Disclosure [Text Block] Loans Acquired with Deteriorated Credit Quality [Member] Financial Instrument [Axis] FAIR VALUES OF FINANCIAL INSTRUMENTS [Abstract] Liabilities [Abstract] Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Assets [Abstract] Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Recorded Balance Financing Receivable, Modifications, Subsequent Default, Recorded Investment Allowance for loan losses and recorded investment in loans by portfolio segment [Abstract] Total Loan Ratings by Loan Class Financing Receivable Credit Quality Indicators [Table Text Block] Class of Financing Receivable, Type [Domain] Number of contracts Financing Receivable, Modifications, Subsequent Default, Number of Contracts Pre-modification recorded balance Financing Receivable, Modifications, Pre-Modification Recorded Investment Loans Not Past Due [Member] Balance at beginning of period Balance at end of period Financing Receivable, Allowance for Credit Losses Loans Past Due, 60-89 days [Member] Loans Past Due, 90+ days [Member] Non-Accrual Recoveries credited to allowance Financing Receivable, Allowance for Credit Losses [Line Items] Loans Past Due, 30-59 days [Member] Number of contracts Financing Receivable, Modifications, Number of Contracts Financing Receivable, Modifications [Line Items] Individually evaluated for impairment Financing Receivables, Period Past Due [Axis] Collectively evaluated for impairment Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Loans not Past Due Financing Receivable, Recorded Investment, Current Financing Receivables, Period Past Due [Domain] Post-modification recorded balance Financing Receivable, Modifications, Post-Modification Recorded Investment Financing Receivable, Recorded Investment [Line Items] Analysis of allowance for loan losses by portfolio segment [Roll Forward] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Financing Receivable, Recorded Investment, Past Due [Line Items] Financing Receivable, Impaired [Line Items] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Loans charged against the allowance Financing Receivable, Allowance for Credit Losses, Write-downs Charge offs due to troubled debt restructurings 90+ and Still Accruing Reclassification to loans held for sale Financing Receivable, Reclassification to Held-for-sale Collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment 2020 2023 Increases in gross carrying amount of core deposit intangibles Finite-Lived Intangible Assets, Period Increase (Decrease) Total Finite-Lived Intangible Assets, Net Gross Carrying Amount 2021 Finite-Lived Intangible Assets, Major Class Name [Domain] 2024 and thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Finite-Lived Intangible Assets by Major Class [Axis] Expected amortization period of core deposit intangible asset Estimated useful lives Estimated useful life 2022 Accumulated Amortization Other Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Summary of estimated core deposit intangible amortization [Abstract] Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] 2019 Fixed Income Interest Rate [Member] Other real estate and repossessed assets, net Other real estate and repossessed assets Foreign Government [Member] Gain (loss) on sale of assets Net gains on assets Net (gains) losses on other real estate and repossessed assets Gains (Losses) on Sales of Other Real Estate Goodwill Balance at beginning of year Balance at end of the period Gross Carrying Amount GOODWILL Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Acquired during the year GOODWILL AND OTHER INTANGIBLES Goodwill and Intangible Assets Disclosure [Text Block] Unamortized intangible assets - goodwill [Abstract] Goodwill, Impaired, Accumulated Impairment Loss [Abstract] Increases (decrease) in goodwill Goodwill, Period Increase (Decrease) Goodwill [Roll Forward] GOODWILL AND OTHER INTANGIBLES [Abstract] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Relationship [Domain] Average Recorded Investment Interest Income Recognized, with an allowance for loan losses recorded Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Unpaid Principal Balance, with an allowance for loan losses recorded Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Impaired Loans by class [Abstract] Impaired Financing Receivable, Recorded Investment [Abstract] Recorded Investment Impaired Financing Receivable, Recorded Investment Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Unpaid Principal Balance Average Recorded Investment, with no related allowance for loan losses recorded Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Related Allowance Impaired Financing Receivable, Related Allowance Impaired Loans Recorded Investment, with no related allowance for loan losses recorded Impaired Financing Receivable, with No Related Allowance, Recorded Investment Unpaid Principal Balance, with no related allowance for loan losses recorded Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Average Recorded Investment, with an allowance for loan losses recorded Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Interest Income Recognized, with no related allowance for loan losses recorded Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Recorded Investment, with an allowance for loan losses recorded Impaired Financing Receivable, with Related Allowance, Recorded Investment Income Statement Location [Domain] Income Statement Location [Axis] INCOME TAX [Abstract] Equity in undistributed net income of subsidiaries Income (Loss) from Equity Method Investments Income Before Income Tax Total reclassifications before tax Income Before Income Tax and Equity in Undistributed Net Income of Subsidiaries CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract] CONDENSED STATEMENTS OF OPERATIONS [Abstract] Equity in undistributed net income of subsidiaries Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Income tax expense Income tax expense Income tax expense (benefit) Reconciliation of income tax expense [Abstract] Effective Income Tax Rate Reconciliation, Amount [Abstract] Income tax expense [Abstract] INCOME TAX Income Tax Disclosure [Text Block] Net change in valuation allowance Non-deductible meals, entertainment and memberships Other, net Statutory rate applied to income before income tax Change in statutory rate Tax-exempt income Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount INCOME TAXES Income Tax, Policy [Policy Text Block] Income taxes Increase in accrued expenses and other liabilities Deferred income tax expense Deferred income tax expense (benefit) Increase (Decrease) in Deferred Income Taxes Net increase in total deposits Loans held for sale [Abstract] Increase (Decrease) in Loans Held-for-sale [Abstract] Deferred loan fees and costs Increase (Decrease) in Loans, Deferred Income Increase in accrued income and other assets (Increase) decrease in accrued income and other assets Increase (Decrease) in Other Operating Assets Increase (Decrease) in Stockholders' Equity [Roll Forward] Effect of stock options (in shares) Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] OTHER INTANGIBLES Intangible Assets, Finite-Lived, Policy [Policy Text Block] Goodwill and other intangibles Intangible Assets, Net (Including Goodwill) Amortized intangible assets - core deposits [Abstract] Other intangibles Total Interest Income Interest income Interest and Dividend Income, Operating Accrued interest payable Interest on securities Interest and fees on loans INTEREST INCOME INTEREST EXPENSE Interest Expense [Abstract] Total Interest Expense Interest expense Interest expense Other borrowings and subordinated debentures Interest Expense, Borrowings Summary of interest expense on deposits [Abstract] Interest Expense, Deposits [Abstract] Interest expense on FHLB advances Net Interest Income After Provision for Loan Losses Interest Income (Expense), after Provision for Loan Loss Savings and interest bearing checking Interest Expense, NOW Accounts, Money Market Accounts, and Savings Deposits Deposits Total Interest Expense, Deposits Time deposits under $100,000 Interest Expense, Time Deposits, Less than $100,000 Interest expense on federal funds purchased Interest Expense, Federal Funds Purchased Time deposits of $100,000 or more Interest Expense, Time Deposits, $100,000 or More Net Interest Income Interest Income (Expense), Net Interest-Rate Cap Agreements [Member] Taxable Interest Income [Member] Tax-exempt Interest Rate-Lock Mortgage Loan Commitments [Member] Interest Rate Swap Member] Interest Rate Swap [Member] Interest bearing deposits Interest-bearing Deposits in Banks and Other Financial Institutions Brokered time Interest-bearing Domestic Deposit, Brokered Time Accrued interest receivable Interest Expense [Member] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Amortized Cost and Fair Value of Securities Available for Sale by Contractual Maturity SECURITIES [Abstract] Investment in subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures SECURITIES Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Subordinated debentures Subordinated Debentures Subordinated debentures Long-term Debt, Type [Domain] Long-term Debt, Type [Axis] Compensation and employee benefits Land [Member] LEASES Leases of Lessee Disclosure [Text Block] LEASES [Abstract] LIABILITIES AND SHAREHOLDERS' EQUITY LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract] Liabilities and Equity [Abstract] Total Liabilities Liabilities Total Liabilities and Shareholders' Equity Liabilities and Equity Liabilities [Abstract] Liabilities, Fair Value Disclosure [Abstract] Litigation settlement expense Litigation Settlement, Expense ALLOWANCE FOR LOAN LOSSES Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block] Allowance for loan losses Total ending allowance for loan losses balance Loans and Leases Receivable, Allowance Repayments Loans and Leases Receivable, Related Parties, Proceeds Installment Net of deferred loan fees Net Loans Loans and Leases Receivable, Net Amount Loans [Abstract] Loans Loans [Abstract] Loans and Leases Receivable, Other Information [Abstract] Contractual Principal Loans Receivable Held-for-sale, Amount Total Loans Total Loans Total Loans Loans and Leases Receivable, Net of Deferred Income Summary of loans and leases receivable [Roll Forward] Loans and Leases Receivable, Related Parties [Roll Forward] Loans held for sale, carried at fair value Aggregate Fair Value Loans held for sale Balance at end of year Balance at beginning of year Loans and Leases Receivable, Related Parties New loans and advances Commercial Commercial loans Loans Receivable, Gross, Commercial, Financial and Agricultural Commercial and industrial LOANS AND PAYMENT PLAN RECEIVABLES Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Total Long-term Debt Summary of repayments of FHLB Advances [Abstract] 2019 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2022 Long-term Debt, Maturities, Repayments of Principal in Year Four 2020 Long-term Debt, Maturities, Repayments of Principal in Year Two SECURITIES Marketable Securities, Policy [Policy Text Block] Net gains on securities Securities Marketable Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss Summary of the maturity of time deposits [Abstract] Maturities of Time Deposits [Abstract] Measurement Input Type [Domain] Adjustment for Differences Between Comparable Sales [Member] Measurement Input Type [Axis] Discount Rate [Member] Mortgage loans in process of foreclosure U.S. Agency Residential Mortgage-Backed [Member] Private Label Mortgage-Backed [Member] Non-performing TDR's [Member] CASH FLOW FROM FINANCING ACTIVITIES CASH FLOW USED IN FINANCING ACTIVITIES [Abstract] Net Cash From Financing Activities Net Cash Provided by (Used in) Financing Activities Net income per common share [Abstract] Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Net Cash Used in Investing Activities Net Cash Provided by (Used in) Investing Activities CASH FLOW USED IN INVESTING ACTIVITIES CASH FLOW FROM (USED IN) INVESTING ACTIVITIES [Abstract] Net Cash From Operating Activities Net Cash Provided by (Used in) Operating Activities Net income Net Income Net income Total reclassifications for the period, net of tax ADOPTION OF NEW ACCOUNTING STANDARDS New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Table] OTHER NON-INTEREST INCOME [Abstract] Total Non-interest Expense Noninterest Expense Total Non-Interest Income Noninterest Income NON-INTEREST EXPENSE Noninterest Expense [Abstract] Non-interest bearing NON-INTEREST INCOME Noninterest Income [Abstract] Other Total Total Noninterest Income, Other Operating Income Number of reportable segments No Hedge Designation [Member] No Hedge Designation [Member] Other comprehensive income (loss) before reclassifications OCI, before Reclassifications, Net of Tax, Attributable to Parent Occupancy, net COMMITMENTS TO EXTEND CREDIT AND RELATED FINANCIAL INSTRUMENTS Off-Balance-Sheet Credit Exposure, Policy [Policy Text Block] Open tax year 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months Total Operating Leases, Future Minimum Payments Due Summary of future minimum lease payments under non-cancelable operating leases [Abstract] Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Rental expense on operating leases Operating Leases, Rent Expense, Net Lease liability Right to use asset OPERATING INCOME [Abstract] Total Operating Income Operating Income (Loss) OPERATING EXPENSES [Abstract] Total Operating Expenses Operating Expenses 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2024 and thereafter Operating Leases, Future Minimum Payments, Due Thereafter 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years 2020 Operating Leases, Future Minimum Payments, Due in Two Years Other Real Estate [Roll Forward] Reclassification adjustments for gains included in earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Reclassification adjustment for (income) expense recognized in earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Income tax expense (benefit) Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Unrealized gains (losses) recognized in other comprehensive income (loss) on securities available for sale, net of tax Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax Unrealized gains (losses) recognized in other comprehensive income (loss) on derivative instruments Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax Unrealized gains (losses) recognized in other comprehensive income (loss) on securities available for sale Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax Income tax expense (benefit) Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax Net impairment loss recognized in earnings Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward] Increases to credit losses on securities for which OTTI was previously recognized Additions to credit losses on securities for which no previous OTTI was recognized Balance at end of period Balance at beginning of period Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held Other borrowings Total Other borrowings Other Borrowings Accrued income and other assets Accrued income and other assets Securities available for sale Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax [Abstract] Derivative instruments Unrealized gains (losses) arising during period Gain (Loss) Recognized in Other Comprehensive Income (Loss) (Effective Portion) Unrealized gains (losses) recognized in other comprehensive income (loss) on derivative instruments, net of tax Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Unrealized gain (loss) arising during period Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, before Tax Other investments Administrative and other expenses Accrued expenses and other liabilities Accrued expenses and other liabilities Other Other Noninterest Expense Other income Other Operating Income Other Liabilities [Member] Other comprehensive income (loss) Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent [Abstract] Other Assets [Member] Other comprehensive income (loss) Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Performing TDR's [Member] Aging Analysis of Loans by Class Past Due Financing Receivables [Table Text Block] Share based compensation withholding obligation Share based compensation withholding obligation Payments Related to Tax Withholding for Share-based Compensation Net increase in portfolio loans (loans originated, net of principal payments) Payments for (Proceeds from) Loans and Leases Payment for litigation settlement Repurchase of common stock Payments for Repurchase of Common Stock Disbursements for loans held for sale Payments for Origination of Mortgage Loans Held-for-sale Purchase of Federal Reserve Bank stock Payments to Acquire Federal Reserve Bank Stock Dividends paid Payments of Dividends Purchases of securities available for sale Payments to Acquire Available-for-sale Securities Capital expenditures Payments to Acquire Property, Plant, and Equipment Performance stock units [Member] Plan Name [Axis] Plan Name [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Preferred stock, par value (in dollars per share) Preferred Stock, No Par Value Securities [Member] Preferred Stock [Member] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, no par value, 200,000 shares authorized; none issued or outstanding Preferred Stock, Value, Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding RECLASSIFICATION Net increase (decrease) in other borrowings Proceeds from the maturity of interest bearing deposits - time Maturity of interest bearing deposits - time Proceeds from (Payments for) in Interest-bearing Deposits in Banks Cash received from the sale of Mepco Finance Corporation assets, net Cash proceeds from sale of assets Proceeds from issuance of common stock Proceeds from issuance of common stock Proceeds from Federal Home Loan Bank advances Proceeds from FHLBank Borrowings, Financing Activities Proceeds from bank-owned life insurance Proceeds from maturities, prepayments and calls of securities available for sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Proceeds from the sale of other real estate and repossessed assets Proceeds from the sale of property and equipment Proceeds from the sale of securities available for sale Proceeds Proceeds from the sale of portfolio loans Proceeds from Sale of Loans Held-for-investment Proceeds from sales of loans held for sale Proceeds from Sale of Loans Held-for-sale Cash proceeds received Legal and professional Property, Plant and Equipment, Type [Axis] Estimated useful lives Property, Plant and Equipment, Useful Life Property, Plant and Equipment [Line Items] PROPERTY AND EQUIPMENT Property, Plant and Equipment Disclosure [Text Block] PROPERTY AND EQUIPMENT [Abstract] Property and Equipment [Abstract] Property and equipment, gross Summary of Property and Equipment Property, Plant and Equipment [Table Text Block] PROPERTY AND EQUIPMENT Property, Plant and Equipment, Net [Abstract] Property, Plant and Equipment, Type [Domain] Property and equipment, net Property and equipment, net Provision for loan losses Provision for loan losses Additional provision for loan losses on impaired loans OTHER REAL ESTATE [Abstract] Additions charged to expense Real Estate Owned, Valuation Allowance, Provision OTHER REAL ESTATE Real Estate Owned [Text Block] Real Estate Owned Valuation Allowance [Roll Forward] Direct write-downs upon sale Real Estate Owned, Valuation Allowance, Amounts Applied Other real estate, valuation allowance Balance at end of year Balance at beginning of year Real Estate Owned, Valuation Allowance Credit Losses Recognized in Earnings on Securities Available for Sale LOANS AND PAYMENT PLAN RECEIVABLES [Abstract] Amounts reclassified from AOCL Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Reclassification out of Accumulated Other Comprehensive Income [Member] Reclassification Out Of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassifications Out of Each Component of AOCL Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income [Domain] Changes in unrecognized tax benefits [Roll Forward] REGULATORY MATTERS Regulatory Capital Requirements under Banking Regulations [Text Block] RELATED PARTY TRANSACTIONS [Abstract] Related Party Transaction [Line Items] Directors and executive officers deposit Related Party Transaction [Abstract] RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] Payments of Federal Home Loan Bank advances Payments of FHLBank Borrowings, Financing Activities Residential Real Estate [Member] Residential First Mortgages [Member] Residential Mortgage [Member] Mortgage [Member] Mortgage [Member] Restricted Stock [Member] RESTRICTIONS ON CASH AND DUE FROM BANKS Restricted Assets Disclosure [Text Block] RESTRICTIONS ON CASH AND DUE FROM BANKS [Abstract] Accumulated deficit Accumulated Deficit [Member] Revenue from contracts with customers Non-interest income Revenue from Contract with Customer, Excluding Assessed Tax Revenue, Initial Application Period Cumulative Effect Transition [Table] REVENUE FROM CONTRACTS WITH CUSTOMERS [Abstract] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] REVENUE FROM CONTRACTS WITH CUSTOMERS LOAN REVENUE RECOGNITION CONCENTRATIONS OF CREDIT RISK [Abstract] Outstanding, weighted-average remaining contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Exercisable, weighted-average remaining contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Vested and expected to vest, weighted-average remaining contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Exercisable, aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Expected life Estimated Amortization of Other Intangible Assets Plan [Member] As Adjusted [Member] Scenario, Unspecified [Domain] Schedule of Financing Receivables Past Due [Table] Summary of Loans to Directors and Executive Officers Schedule of Related Party Transactions [Table Text Block] Reconciliation of Income Tax Expense Computed by Applying the Statutory Federal Income Tax Rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Weighted-average Assumptions Used Black-Scholes Option Pricing Model Investments in a Continuous Unrealized Loss Position Reconciliation of Basic and Diluted Net Income Per Share Gains and Losses Realized on Sale of Securities Available for Sale Schedule of Realized Gain (Loss) [Table Text Block] Outstanding Stock Option Grants and Transactions Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Preliminary Valuation of Assets Acquired and Liabilities Assumed Changes in Unrecognized Tax Benefits Loans on Non-Accrual Status and Past Due More than 90 Days Schedule of Impaired Financing Receivable [Table] Summary of Future Minimum Lease Payments under Non-cancelable Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Non-Vested Restricted Stock, Restricted Stock Units and PSU's Debt Securities, Available-for-sale [Line Items] Analysis of Allowance for Loan Losses by Portfolio Segment Accumulated Other Comprehensive Loss (AOCL), Net of Tax Securities Available for Sale Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Other Intangible Assets, Net of Amortization Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Composition of Income Tax Expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Deferred Tax Assets and Deferred Tax Liabilities