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 Award Type [Axis] Number of securities with market fair value less than amortized cost ACCOUNTING POLICIES [Abstract] ASU 2016-09 [Member] Accounting Standards Update 2016-09 [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accumulated Other Comprehensive Income (Loss) [Table] Unrealized Gains on Cash Flow Hedges [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated other comprehensive loss Accumulated other comprehensive loss for regulatory purposes Accumulated Other Comprehensive Income (Loss), Net of Tax ACCUMULATED OTHER COMPREHENSIVE LOSS [Abstract] Unrealized Gains (Losses) on Securities Available For Sale [Member] Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment 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 Other Comprehensive Loss [Member] 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 (USED) IN OPERATING ACTIVITIES Share based compensation withholding obligation Adjustments Related to Tax Withholding for Share-based Compensation Adjustments for New Accounting Pronouncements [Axis] Adjustments for Change in Accounting Principle [Axis] Advances from the FHLB Total FHLB advances, Amount 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 Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities, Name [Domain] Antidilutive shares excluded from computation of diluted loss per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Other real estate, additional charge Impairment charges recognized [Abstract] Other Asset Backed [Member] Assets [Abstract] Assets, Fair Value Disclosure [Abstract] ASSETS ASSETS [Abstract] Assets [Abstract] Total Assets Total assets Less Than Twelve Months, Unrealized Losses Twelve Months or More, Unrealized Losses Total, Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] Total available-for-sale securities fair value Available-for-sale Securities, Debt Maturities, Single Maturity Date Unrealized gains Available-for-sale Securities, Amortized Cost Basis [Abstract] Maturing after five years but within ten years Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis Twelve Months or More, Fair Value Total, Fair value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Securities available for sale Fair value Securities available for sale Unrealized losses Less Than Twelve Months, Fair Value Maturing after five years but within ten years Amortized cost Available-for-sale Securities, Amortized Cost Basis Available-for-sale securities, debt maturities, amortized cost basis Available-for-sale Debt Securities, Amortized Cost Basis Gain and losses realized on sale of securities available for sale [Abstract] Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract] Maturing after ten years Maturing after ten years Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis Maturing after one year but within five years Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis Losses Maturing after one year but within five years U.S. agency residential mortgage-backed Realized gains Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract] U.S. agency residential mortgage backed Proceeds Maturing within one year Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis Maturing within one year Balance Sheet Location [Domain] Balance Sheet Location [Axis] Bank-owned life insurance Bank owned life insurance Bank Owned Life Insurance Income REGULATORY MATTERS [Abstract] Buildings [Member] Building [Member] Business Acquisition, Acquiree [Domain] Business Acquisition [Axis] PENDING ACQUISITION [Abstract] Merger related expense Non-interest expense amount Counterparty Name [Axis] Total capital to risk-weighted assets [Abstract] Total risk-based capital Capital Minimum for Adequately Capitalized Institutions, Ratio Minimum for Well Capitalized Institutions, Amount Minimum for Adequately Capitalized Institutions, Amount Actual, Ratio Capital to Risk Weighted Assets Minimum for Well-Capitalized Institutions, Ratio Recorded Book Balance [Member] Reported Value Measurement [Member] Cash and due from banks STATEMENTS OF CASH FLOWS 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 Information regarding options exercised Net Increase (Decrease) in Cash and Cash Equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and due from banks Cash and Cash Equivalents, Fair Value Disclosure 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] Change in Accounting Method [Member] Change in Accounting Method Accounted for as Change in Estimate [Member] Adjustments for Change in Accounting Principle [Domain] Change in Accounting Estimate, Type [Domain] Change in Accounting Estimate by Type [Axis] Class of Stock [Domain] Stock Reserved [Line Items] Class of Stock [Line Items] U.S. Agency Commercial Mortgage-Backed [Member] Commercial and Industrial [Member] Commercial and Industrial [Member] Commercial [Member] Commercial [Member] COMMITMENTS AND CONTINGENT LIABILITIES Commitments and Contingencies Disclosure [Text Block] Commitments and contingent liabilities Commitments to Extend Credit [Member] COMMITMENTS AND CONTINGENT LIABILITIES [Abstract] Common stock reserved for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Common stock, par value (in dollars per share) Declared (in dollars per share) Common Stock [Member] Common stock, shares authorized (in shares) Common stock, shares issued (in shares) Common equity tier 1 capital to risk-weighted assets [Abstract] Common Equity Tier One Capital [Abstract] Common equity tier 1 capital Actual, Amount Common Equity Tier One Capital Minimum for Adequately Capitalized Institutions, Amount Common Equity Tier One Capital Required for Capital Adequacy Minimum for Well-Capitalized Institutions, Amount Common Equity Tier One Capital Required to be Well-Capitalized Common Stock Subject to Mandatory Redemption [Member] Common Stock [Abstract] Common stock, no par value, 500,000,000 shares authorized; issued and outstanding: 21,333,869 shares at December 31, 2017 and 21,258,092 shares at December 31, 2016 Common Stock, Value, Issued Common stock, shares outstanding (in shares) Communications Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Components of deferred tax assets and liabilities [Abstract] COMPREHENSIVE INCOME Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent ACCUMULATED OTHER COMPREHENSIVE LOSS Comprehensive Income (Loss) Note [Text Block] Concentration Risk Type [Domain] CONCENTRATIONS OF CREDIT RISK Concentration Risk Disclosure [Text Block] Concentration Risk [Line Items] Concentration Risk Type [Axis] Concentration Risk [Table] Condensed Financial Statements, Captions [Line Items] INDEPENDENT BANK CORPORATION (PARENT COMPANY ONLY) FINANCIAL INFORMATION Condensed Financial Information of Parent Company Only Disclosure [Text Block] INDEPENDENT BANK CORPORATION (PARENT COMPANY ONLY) FINANCIAL INFORMATION [Abstract] Consolidated Entities [Domain] Consolidated Entities [Axis] Consolidated [Member] Consolidated Entities [Member] PRINCIPLES OF CONSOLIDATION Consumer [Member] Retail [Member] Corporate [Member] Cumulative effect of change in accounting Cumulative effect of change in accounting Current expense Designated as Hedging Instrument [Member] Issue Date Debt Instrument, Issuance Date Interest Rate Interest Rate Spread Debt Instrument, Basis Spread on Variable Rate OTHER BORROWINGS Debt Disclosure [Text Block] OTHER BORROWINGS [Abstract] Maturity Date Trust Preferred Securities Issued Debt Instrument, Face Amount Unrealized loss on securities available for sale Property and equipment Deferred Tax Assets, Property, Plant and Equipment Deferred expense Gross deferred tax liabilities Deferred Tax Liabilities, Gross Other Deferred Tax Assets, Other Loss carryforwards Deferred tax assets, net Deferred tax assets, net Deferred tax assets, net Gross deferred tax assets Deferred Tax Assets, Gross Gross deferred tax assets net of valuation allowance Deferred Tax Assets, Net of Valuation Allowance Deferred tax assets [Abstract] Litigation settlement Alternative minimum tax credit carry forward Valuation allowance Deferred Tax Assets, Valuation Allowance Allowance for loan losses Deferred compensation Unrealized loss on trading securities Share based payments 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] Deposits DEPOSITS [Abstract] Total Deposits Deposits Savings and interest-bearing checking 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 Depreciation expense Derivative financial instruments Derivatives Average Maturity Notional Amount Derivative Instrument [Axis] Derivative Instrument [Axis] DERIVATIVE FINANCIAL INSTRUMENTS [Abstract] Derivative financial instrument according to type of hedge[ Abstract] Derivative financial instruments Derivatives Derivative Liability DERIVATIVE FINANCIAL INSTRUMENTS Derivative Instruments and Hedging Activities Disclosure [Text Block] Fair Value Gain (Loss) Recognized in Income Asset Derivatives Derivative Asset, Fair Value, Gross Asset Liability Derivatives Fair value of derivative instruments, balance sheet location [Abstract] Hedging Relationship [Axis] Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Derivative Instruments, Gain (Loss) [Line Items] Gain Recognized in Other Comprehensive Income (Loss) (Effective Portion) Derivative Instruments, Gain (Loss) [Table] Derivative Contract [Domain] DERIVATIVE FINANCIAL INSTRUMENTS Derivatives, Fair Value [Line Items] 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 Diluted (in dollars per share) Earnings Per Share, Diluted 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] Net income per common share Statutory federal income tax rate Tax benefit realized Stock Options [Member] Total compensation cost not yet recognized Tax benefit relating to compensation expense recognized Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Total compensation cost not yet recognized, period for recognition Furniture, fixtures and equipment Equipment Expense Equipment [Member] Equity Component [Domain] Custodial deposit accounts Escrow Deposit Fair Value [Member] Fair Value Measurements [Member] Executive Officers [Member] Asset (Liability) Fair Value [Abstract] Included in results of operations Total Change in Fair Values Included in Current Period Earnings Fair Value, Option, Changes in Fair Value, Gain (Loss) Amount of total losses for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets and liabilities still held at December 31 Included in other comprehensive income Discount rate Liability Class [Axis] Measurement Basis [Axis] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Measurement Frequency [Axis] Fair Value, Measurements, Nonrecurring [Member] Assets and liabilities measured at fair value [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] Asset Class [Axis] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Measurement Frequency [Domain] FAIR VALUE DISCLOSURES [Abstract] Changes in fair value for financial assets [Abstract] Asset Class [Domain] Fair Value, Measurements, Recurring [Member] Fair Value by Liability Class [Domain] Assets and liabilities measured at fair value Fair Value Hierarchy [Domain] FAIR VALUE DISCLOSURES Fair Value Disclosures [Text Block] Quantitative information about Level 3 fair value measurements measured on a non-recurring basis Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [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] Estimated fair values and recorded book balances Fair Value, by Balance Sheet Grouping [Table Text Block] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value Measurement [Domain] Concentration of risk loans receivable 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] Significant Unobservable Inputs, (Level 3) [Member] Significant Unobservable Inputs (Level 3) [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Difference Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) [Roll Forward] Purchases, issuances, settlements, maturities and calls Ending balance Beginning balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Transfers in and/or out of Level 3 Fair Value, Option, Quantitative Disclosures [Line Items] Fair Value, Option, Quantitative Disclosures [Table] Changes in fair value for financial assets Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] 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 2017, Amount FDIC deposit insurance FHLB advances terminated Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Repayment and Penalties Federal funds purchased Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] Federal home loan bank stock Advances from Federal Home Loan Bank ("FHLB") [Member] Unused borrowing capacity with FHLB Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds Total fixed-rate advances, amount Federal Home Loan Bank, Advances, Maturities Summary, Fixed Rate 2018, Amount 2020, Rate 2019, Amount Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Three 2018, Rate 2017, Rate Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due within One Year of Balance Sheet Date 2020, Amount 2019, Rate Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Two to Three Years from Balance Sheet Date Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract] Variable-rate advances - 2018, amount Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due [Abstract] Federal Reserve Bank Advances [Member] Federal Reserve Bank Advances [Member] Service charges on deposit accounts 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] Financial Instrument [Axis] Liabilities [Abstract] Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] FAIR VALUES OF FINANCIAL INSTRUMENTS [Abstract] Assets [Abstract] Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Financing Receivable, Recorded Investment, Past Due [Line Items] Post-modification recorded balance Financing Receivable, Modifications, Post-Modification Recorded Investment Financing Receivable, Modifications [Line Items] Number of contracts Financing Receivable, Modifications, Subsequent Default, Number of Contracts Collectively evaluated for impairment Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Financing Receivable, Allowance for Credit Losses [Line Items] Class of Financing Receivable, Type [Domain] Financing Receivable, Recorded Investment [Line Items] 90+ and Still Accruing Loans Past Due, 90+ days [Member] Individually evaluated for impairment Loans Past Due, 60-89 days [Member] Balance at end of period Balance at beginning of period Financing Receivable, Allowance for Credit Losses Analysis of allowance for loan losses by portfolio segment [Roll Forward] Pre-modification recorded balance Financing Receivable, Modifications, Pre-Modification Recorded Investment Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Reclassification to loans held for sale Financing Receivable, Reclassification to Held-for-sale Summary of loan ratings by loan class Financing Receivable Credit Quality Indicators [Table Text Block] Collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Recoveries credited to allowance Recorded Balance Financing Receivable, Modifications, Subsequent Default, Recorded Investment Loans Past Due, 30-59 days [Member] Allowance for loan losses and recorded investment in loans by portfolio segment [Abstract] Financing Receivable, Impaired [Line Items] Financing Receivables, Period Past Due [Domain] Loans Not Past Due [Member] Financing Receivables, Period Past Due [Axis] Loans charged against the allowance Financing Receivable, Allowance for Credit Losses, Write-downs Number of contracts Financing Receivable, Modifications, Number of Contracts Loans not Past Due Financing Receivable, Recorded Investment, Current Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Charge offs due to troubled debt restructurings Total Non-Accrual Total Finite-Lived Intangible Assets, Net 2018 Other Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] 2022 Accumulated Amortization Summary of estimated core deposit intangible amortization [Abstract] Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] 2020 Estimated useful lives 2021 Gross Carrying Amount 2019 Fixed Income Interest Rate [Member] Other real estate and repossessed assets Other real estate and repossessed assets Foreign Government [Member] Gain (loss) on sale of assets Net gains on securities Net (gains) losses on other real estate and repossessed assets Gains (Losses) on Sales of Other Real Estate Net gains on assets INTANGIBLE ASSETS [Abstract] Hedging Designation [Axis] Hedging Relationship [Domain] Hedging Designation [Domain] Interest Income Recognized, with No Related Allowance Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Recorded Investment, with no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Recorded Investment Related Allowance Impaired Financing Receivable, Related Allowance Average Recorded Investment, with No Related Allowance Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Interest Income Recognized, with Related Allowance Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Unpaid Principal Balance, with no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Impaired Loans by class [Abstract] Impaired Financing Receivable, Recorded Investment [Abstract] Impaired loans Recorded Investment Impaired Financing Receivable, Recorded Investment Recorded Investment, with an allowance recorded Impaired Financing Receivable, with Related Allowance, Recorded Investment Average Recorded Investment Unpaid Principal Balance, with an allowance recorded Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Unpaid Principal Balance Average Recorded Investment, with Related Allowance Impaired Financing Receivable, with Related Allowance, Average Recorded Investment INCOME TAX [Abstract] Income Statement Location [Axis] Income Approach [Member] Income Before Income Tax Total reclassifications before tax Income (Loss) Before Income Tax and Equity in Undistributed Net Income of Subsidiaries Income Statement Location [Domain] Equity in undistributed net income of subsidiaries Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Equity in undistributed net income of subsidiaries Income (Loss) from Equity Method Investments CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract] CONDENSED STATEMENTS OF OPERATIONS [Abstract] INCOME TAX Income Tax Disclosure [Text Block] Statutory rate applied to income before income tax Income tax expense (benefit) [Abstract] Reconciliation of income tax expense [Abstract] Effective Income Tax Rate Reconciliation, Amount [Abstract] Change in statutory rate Net change in valuation allowance Income tax expense Income tax expense (benefit) Income tax expense Non-deductible meals, entertainment and memberships Other, net Income taxes INCOME TAXES Income Tax, Policy [Policy Text Block] Tax-exempt income Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Increase (decrease) 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 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 Fair value option - Loans held for sale [Abstract] Increase (Decrease) in Loans Held-for-sale [Abstract] Increase (Decrease) in Stockholders' Equity [Roll Forward] Effect of stock options (in shares) OTHER INTANGIBLES Intangible Assets, Finite-Lived, Policy [Policy Text Block] Amortized intangible assets - core deposits [Abstract] Other intangibles Intangible assets INTANGIBLE ASSETS Intangible Assets Disclosure [Text Block] Accrued interest payable Interest and fees on loans INTEREST INCOME Interest on securities Total Interest Income Interest income Interest and Dividend Income, Operating INTEREST EXPENSE Interest Expense [Abstract] Other borrowings and subordinated debentures Interest Expense, Borrowings Summary of interest expense on deposits [Abstract] Interest Expense, Deposits [Abstract] Deposits Total Interest Expense, Deposits Interest expense on federal funds purchased Interest Expense, Federal Funds Purchased Interest expense on FHLB advances Total Interest Expense Interest expense Interest expense Net Interest Income After Provision for Loan Losses Interest Income (Expense), after Provision for Loan Loss Time deposits under $100,000 Interest Expense, Time Deposits, Less than $100,000 Net Interest Income Interest Income (Expense), Net Time deposits of $100,000 or more Interest Expense, Time Deposits, $100,000 or More Interest Tax-exempt Interest Income [Member] Savings and interest bearing checking Interest Expense, NOW Accounts, Money Market Accounts, and Savings Deposits Taxable Rate-Lock Mortgage Loan Commitments [Member] Interest Rate Swap [Member] Interest Rate Swap [Member] Interest-Rate Cap Agreements [Member] Brokered time Interest-bearing Domestic Deposit, Brokered Interest bearing deposits Interest-bearing Deposits in Banks and Other Financial Institutions Time Interest Expense [Member] Accrued interest receivable Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] SECURITIES Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Investment in subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Amortized cost and fair value of securities available for sale by contractual maturity SECURITIES [Abstract] 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] Total Liabilities and Shareholders' Equity Total Liabilities and Shareholders' Equity Total Liabilities Liabilities LIABILITIES AND SHAREHOLDERS' EQUITY LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract] Liabilities and Equity [Abstract] Liabilities [Abstract] Liabilities, Fair Value Disclosure [Abstract] Litigation settlement expense Litigation Settlement, Expense Repayments Loans and Leases Receivable, Related Parties, Proceeds Total ending allowance balance Allowance for loan losses Loans and Leases Receivable, Allowance Installment Net of deferred loan fees ALLOWANCE FOR LOAN LOSSES Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block] Total Loans Total Loans Total Loans Loans and Leases Receivable, Net of Deferred Income Loans [Abstract] Loans and Leases Receivable, Other Information [Abstract] Loans Loans [Abstract] Net Loans Loans and Leases Receivable, Net Amount Commercial and industrial Balance at end of year Balance at beginning of year Loans and Leases Receivable, Related Parties Summary of loans and leases receivable [Roll Forward] Loans and Leases Receivable, Related Parties [Roll Forward] Commercial Commercial loans Loans Receivable, Gross, Commercial, Financial and Agricultural Loans Held For Sale [Member] Loans held for sale, carried at fair value Loans held for sale Loans held for sale Contractual Principal Loans Receivable Held-for-sale, Amount New loans and advances 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] 2020 Long-term Debt, Maturities, Repayments of Principal in Year Three 2018 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2019 Long-term Debt, Maturities, Repayments of Principal in Year Two Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Axis] SECURITIES Marketable Securities, Policy [Policy Text Block] Trust preferred securities Marketable Securities [Table Text Block] Net gains on securities Securities Marketable Securities, Gain (Loss), Excluding Other than Temporary Impairments Summary of the maturity of time deposits [Abstract] Maturities of Time Deposits [Abstract] Maximum [Member] Minimum [Member] Weighted average interest rate Mortgage Loans on Real Estate, Loan Type [Domain] Mortgage Loans on Real Estate, Loan Type [Axis] Mortgage loans in process of foreclosure Private Label Mortgage-Backed [Member] U.S. Agency Residential Mortgage-Backed [Member] Non-performing TDR's [Member] Net Cash From Financing Activities Net Cash Provided by (Used in) Financing Activities CASH FLOW FROM FINANCING ACTIVITIES CASH FLOW USED IN FINANCING ACTIVITIES [Abstract] CASH FLOW USED IN INVESTING ACTIVITIES CASH FLOW FROM INVESTING ACTIVITIES [Abstract] Net Cash Used in Investing Activities Net Cash Provided by (Used in) Investing Activities 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 Net Income (Loss) Attributable to Parent Net income per common share [Abstract] Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncement, Effect of Early Adoption [Member] New Accounting Pronouncement, Early Adoption, Effect [Member] Cumulative effect of adjustments ADOPTION OF NEW ACCOUNTING STANDARDS New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Standards [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Line Items] NON-INTEREST INCOME Noninterest Income [Abstract] Non-interest bearing NON-INTEREST EXPENSE Noninterest Expense [Abstract] OTHER NON-INTEREST INCOME [Abstract] Total Non-Interest Income Noninterest Income Other Total other non-interest income Noninterest Income, Other Operating Income Total Non-interest Expense Noninterest Expense 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 OPERATING INCOME [Abstract] OPERATING EXPENSES [Abstract] Operating loss carryforwards amount, expiration date 2023 and thereafter Operating Leases, Future Minimum Payments, Due Thereafter 2019 Operating Leases, Future Minimum Payments, Due in Two Years Rental expense on operating leases Operating Leases, Rent Expense, Net Summary of future minimum lease payments under non-cancelable operating leases [Abstract] Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Total Operating Leases, Future Minimum Payments Due 2018 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2022 Operating Leases, Future Minimum Payments, Due in Five Years 2021 Operating Leases, Future Minimum Payments, Due in Four Years Total Operating Income Operating Income (Loss) Total Operating Expenses Operating Expenses 2020 Operating Leases, Future Minimum Payments, Due in Three Years Operating loss carryforwards amount Reclassification adjustment for expense recognized in earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Reclassification adjustments for gains included in earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Unrealized gains (losses) recognized in other comprehensive income (loss) on securities available for sale Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax Income tax expense 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), Available-for-sale Securities Adjustment, Net of Tax Income tax expense (benefit) Other Comprehensive Income (Loss), Available-for-sale Securities, Tax Other Real Estate [Roll Forward] Unrealized gains recognized in other comprehensive income (loss) on derivative instruments Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax Other real-estate [Abstract] Net impairment loss recognized in earnings OTTI changes recorded in earnings Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities Increases to credit losses on securities for which OTTI was previously recognized Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward] Balance at beginning of period Balance at end of period Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held Additions to credit losses on securities for which no previous OTTI was recognized Other borrowings Other borrowings Total Other Borrowings Securities available for sale Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, [Abstract] Accrued income and other assets Accrued income and other assets Derivative instruments Unrealized gain arising during period Unrealized gains 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), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax Administrative and other expenses Other investments Accrued expenses and other liabilities Accrued expenses and other liabilities Other Other Noninterest Expense Other income Other Operating Income Other Liabilities [Member] Other Assets [Member] Other comprehensive income (loss) Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent [Abstract] 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] Parent Company [Member] Parent Company [Member] 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 Dividends paid Payments of Dividends Disbursements for loans held for sale Payments for Origination of Mortgage Loans Held-for-sale Payment for litigation settlement Purchase of Federal Reserve Bank stock Payments to Acquire Federal Reserve Bank Stock Purchases of securities available for sale Payments to Acquire Available-for-sale Securities Repurchase of common stock Payments for Repurchase of Common Stock 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 Preferred stock, no par value, 200,000 shares authorized; none issued or outstanding Preferred Stock, Value, Issued Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized RECLASSIFICATION Net increase (decrease) in other borrowings Cash received from the sale of Mepco Finance Corporation assets, net Cash proceeds from sale of assets Proceeds from Federal Home Loan Bank advances Proceeds from Federal Home Loan Bank Borrowings Proceeds from issuance of common stock Proceeds from issuance of common stock Proceeds from maturities, prepayments and calls of securities available for sale Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Proceeds from the sale of securities available for sale Proceeds from bank-owned life insurance Proceeds from the sale of other real estate and repossessed assets Proceeds from sales of loans held for sale Proceeds from Sale of Loans Held-for-sale Cash proceeds received Proceeds from the sale of property and equipment Legal and professional PROPERTY AND EQUIPMENT Summary of property and equipment Property, Plant and Equipment [Table Text Block] PROPERTY AND EQUIPMENT [Abstract] Property and Equipment [Abstract] Property and equipment, net Property and equipment, net Property and equipment, gross PROPERTY AND EQUIPMENT Property, Plant and Equipment Disclosure [Text Block] Property, Plant and Equipment [Line Items] Estimated useful lives Property, Plant and Equipment, Useful Life Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Provision for loan losses Provision for loan losses Additional provision for loan losses on impaired loans Range [Domain] Range [Axis] OTHER REAL ESTATE [Abstract] Additions charged to expense Real Estate Owned, Valuation Allowance, Provision Direct write-downs upon sale Real Estate Owned, Valuation Allowance, Amounts Applied OTHER REAL ESTATE Real Estate Owned [Text Block] Real Estate Owned Valuation Allowance [Roll Forward] Balance at end of year Balance at beginning of year Other real estate, valuation allowance 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 Summary of reclassifications out of each component of AOCL Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] 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 [Domain] Reclassification out of Accumulated Other Comprehensive Income [Axis] Changes in unrecognized tax benefits [Roll Forward] REGULATORY MATTERS Regulatory Capital Requirements under Banking Regulations [Text Block] Related Party Transaction [Line Items] Directors and executive officers deposit RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] RELATED PARTY TRANSACTIONS [Abstract] Payments of Federal Home Loan Bank Advances Repayments of Federal Home Loan Bank Borrowings Counterparty Name [Domain] Residential First Mortgages [Member] Residential Mortgage [Member] Residential Real Estate [Member] Mortgage [Member] Mortgage [Member] Cumulative Retrospective Adjustments [Member] Restatement Adjustment [Member] Restricted Stock [Member] RESTRICTIONS ON CASH AND DUE FROM BANKS [Abstract] RESTRICTIONS ON CASH AND DUE FROM BANKS Restricted Assets Disclosure [Text Block] Accumulated deficit Accumulated Deficit [Member] LOAN REVENUE RECOGNITION CONCENTRATIONS OF CREDIT RISK [Abstract] 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, weighted-average remaining contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Exercisable, aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Outstanding, weighted-average remaining contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Estimated amortization of other intangible assets Scenario, Unspecified [Domain] Plan [Member] As Adjusted [Member] Originally Presented [Member] Scenario, Previously Reported [Member] CONDENSED STATEMENTS OF OPERATIONS Condensed Income Statement [Table Text Block] Summary of outstanding stock option grants and transactions Summary of deferred tax assets and deferred tax liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Summary of loans to directors and executive officers Schedule of Related Party Transactions [Table Text Block] Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] CONDENSED STATEMENTS OF FINANCIAL CONDITION Condensed Balance Sheet [Table Text Block] Schedule of changes in unrecognized tax benefits Reconciliation of basic and diluted loss per share Schedule of Finite-Lived Intangible Assets [Table] CONDENSED STATEMENTS OF CASH FLOWS Condensed Cash Flow Statement [Table Text Block] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Analysis of allowance for loan losses by portfolio segment Reconciliation of income tax expense computed by applying the statutory federal income tax rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Investments in a continuous unrealized loss position Loans on non-accrual status and past due more than 90 days Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Summary of non-vested restricted stock and stock units and transactions Schedule of Impaired Financing Receivable [Table] Gains and losses realized on sale of securities available for sale Schedule of Realized Gain (Loss) [Table Text Block] Summary of future minimum lease payments under non-cancelable operating leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Composition of income tax expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Securities available for sale Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Available-for-sale Securities [Table] Actual capital amounts and ratios Other intangible assets, net of amortization Schedule of Available-for-sale Securities [Line Items] Schedule of Condensed Financial Statements [Table] Schedule of accumulated other comprehensive loss (AOCL), net of tax Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Fair Value, Off-balance Sheet Risks [Table] Financial instruments with off-balance sheet risk Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] Condensed consolidated statement of financial position to reflect cumulative effect of adjustments Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Schedule of Related Party Transactions, by Related Party [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Schedule of Short-term Debt [Table] Schedule of Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Axis] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of information regarding subordinated debentures Schedule of Subordinated Borrowing [Table Text Block] Effect of derivative financial instruments on consolidated statement of operation Loan portfolios Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Fair value of derivative instruments Schedule of Stock by Class [Table] OPERATING SEGMENTS Operating Segments [Abstract] Segment Reporting [Abstract] Geographical [Domain] Capitalized mortgage loan servicing rights Balance at end of year Servicing Asset at Fair Value, Amount Change in valuation allowance Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs Originated servicing rights capitalized Balance at end of year Balance at beginning of period Capitalized mortgage loan servicing rights Servicing Asset at Amortized Cost Capitalized mortgage loan servicing rights, carrying amount Servicing Asset at Amortized Cost, Fair Value Change in valuation allowance Originated servicing rights capitalized Servicing Asset at Fair Value, Additions Average discount rate Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate Mortgage loan servicing, net Information regarding options exercised [Abstract] Number of additional shares approved for grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Forfeited (in dollars per share) Weighted-Average Grant Date Fair Value [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Share based compensation Share-based Compensation Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Average Exercise Price [Roll Forward] Expired (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Exercisable, period end (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Granted (in dollars per share) Granted (in shares) Outstanding, beginning balance (in dollars per share) Outstanding, ending balance (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 Weighted-Average Remaining Contractual Term [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]