Investments, Debt and Equity Securities [Abstract] SECURITIES AVAILABLE FOR SALE, HELD TO MATURITY, AND OTHER Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Fixed rate advances Federal Home Loan Bank Fixed Rate Advances [Member] Fixed rate borrowings from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and also in times of liquidity shortages. Range [Axis] Range [Axis] Range [Domain] Range [Domain] Weighted Average Weighted Average [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Principal Federal Home Loan Bank, Advances, Rolling Maturity [Abstract] 2018 Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Rolling Twelve Months 2019 Federal Home Loan Bank, Advances, Maturities Summary, Due in Rolling Year Two 2020 Federal Home Loan Bank, Advances, Maturities Summary, Due in Rolling Year Three 2021 Federal Home Loan Bank, Advances, Maturities Summary, Due in Rolling Year Four 2022 and beyond Federal Home Loan Bank, Advances, Maturities Summary, Due after Rolling Year Four Amount of advances from Federal Home Loan Bank (FHLBank) maturing after the fourth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. Total FHLB advances Advances from Federal Home Loan Banks Weighted Average Rate (as a percent) Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due [Abstract] 2018 Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due within One Year of Balance Sheet Date 2019 Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, One to Two Years from Balance Sheet Date 2020 Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Two to Three Years from Balance Sheet Date 2021 Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Three to Four Years from Balance Sheet Date 2022 and beyond Federal Home Loan Bank Advances Maturities Summary Average Interest Rate of Amounts Due after Four Years of Balance Sheet Date The weighted average interest rate applicable to the Federal Home Loan Bank advances maturing after the fourth fiscal year following the latest fiscal year. Total FHLB advances Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate at Period End Trading Securities [Abstract] TRADING SECURITY Disclosure of Trading Securities and Certain Trading Assets [Text Block] The entire disclosure for trading securities. Fair Value Disclosures [Abstract] Fair Value Inputs, Assets, Quantitative Information [Table] Fair Value Inputs, Assets, Quantitative Information [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 3 Fair Value, Inputs, Level 3 [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Trading Security Trading Securities [Member] Commitments to Lend Commitments to Extend Credit [Member] Forward Commitments Forward Contracts [Member] Capitalized Servicing Rights Capitalized Mortgage Servicing Rights [Member] Represents the details pertaining to capitalized mortgage servicing rights. Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Discounted Cash Flow Discounted Cash Flow Valuation Technique [Member] Discounted cash flow approach valuation technique used to measure fair value. Historical Trend Historical Trend Valuation Technique [Member] Historical trend approach valuation technique used to measure fair value. Pricing Model Pricing Model Valuation Technique [Member] Pricing model approach valuation technique used to measure fair value. Quantitative information about the significant unobservable inputs within Level 3 Fair Value Inputs, Assets, Quantitative Information [Line Items] Assets measured on recurring basis Assets, Fair Value Disclosure, Recurring Liabilities measured on recurring basis Liabilities, Fair Value Disclosure, Recurring Total Fair Value, Net Asset (Liability) Discount Rate (as percent) Fair Value Inputs, Discount Rate Closing Ratio (as percent) Fair Value Inputs Closing Ratio Represents the closing ratio used as an input to measure fair value. Origination Costs, per loan Fair Value Inputs Origination Costs Represents the origination costs used as an input to measure fair value. Constant prepayment rate (CPR) (as percent) Fair Value Inputs, Prepayment Rate FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-01 Accounting Standards Update 2016-01 [Member] ASU 2018-02 Accounting Standards Update 2018-02 [Member] Accounting Standards Update 2018-02 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Preferred stock Preferred Stock [Member] Common stock Common Stock [Member] Additional paid-in capital Additional Paid-in Capital [Member] Unearned compensation Deferred Compensation, Share-based Payments [Member] Retained earnings Retained Earnings [Member] Accumulated other comprehensive (loss) income AOCI Attributable to Parent [Member] Treasury stock Treasury Stock [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance (in shares) Shares, Outstanding Balance at Beginning of Period Stockholders' Equity Attributable to Parent Comprehensive income: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Net income Net Income (Loss) Attributable to Parent Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Adoption of ASU Cumulative Effect of New Accounting Principle in Period of Adoption Cash dividends declared on common shares Dividends, Common Stock, Cash Cash dividends declared on preferred shares Dividends, Preferred Stock, Cash Forfeited shares (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Forfeited Forfeited shares Stock Issued During Period, Value, Restricted Stock Award, Forfeitures Exercise of stock options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Restricted stock grants (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Restricted stock grants Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Other, net (in shares) Stockholders' Equity, Other Shares Other, net Stockholders' Equity, Other Balance (in shares) Balance at End of Period Revenue from Contract with Customer [Abstract] Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Receivables [Abstract] Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Commercial Real Estate Commercial Real Estate Portfolio Segment [Member] Commercial and industrial loans Commercial and Industrial Loans Portfolio Segment [Member] Commercial and Industrial Loans Portfolio Segment [Member] Residential Mortgages Residential Portfolio Segment [Member] Consumer Loans Consumer Portfolio Segment [Member] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Domain] Class of Financing Receivable, Type [Domain] Construction Construction Loans [Member] Single and multi-family Single And Multi Family [Member] Class of financing receivables related to single family and multi-family financing receivables. Other Other Receivable [Member] Class of financing receivables related to other financing receivables. 1-4 family 1 to 4 Family [Member] Class of financing receivables related to 1 to 4 Family financing receivables. Home equity Home Equity Loan [Member] Auto and other Auto And Other Receivable [Member] Class of financing receivables related to auto and other financing receivables. Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Business Activities Loans Loans From Business Activities [Member] Represents information pertaining to the loans from business activities. Acquired Loans Loans Acquired From Business Combinations [Member] Represents information pertaining to the loans acquired from business combinations. Acquired Credit Impaired Loans Acquired Credit Impaired Loans [Member] Represents the information pertaining to Acquired credit impaired loans. Non-accrual loans Financing Receivable, Recorded Investment, Past Due [Line Items] Non-accrual loans Financing Receivable, Recorded Investment, Nonaccrual Status Trouble Debt Restructuring on Financing Receivables [Roll Forward] Trouble Debt Restructuring on Financing Receivables [Roll Forward] Trouble Debt Restructuring on Financing Receivables [Roll Forward] Balance at beginning of the period Financing Receivable, Modifications, Recorded Investment Principal payments Financing Receivable Troubled Debt Restructuring Principal Payments Represents the amount of principal payment of financing receivables modified by troubled debt restructurings. TDR status change Financing Receivable Troubled Debt Restructuring Status Change Represents the amount of troubled debt restructurings status change in which troubled debt restructuring loans with a specified interest rate equal to or greater than the rate that the entity was willing to accept at the time of the restructuring for a new loan with comparable risk and the loan was on current payment status and not impaired based on the terms specified by the restructuring agreement. Other reductions/increases Financing Receivable Troubled Debt Restructuring Other Increase (Decrease) Financing Receivable Troubled Debt Restructuring Other Increase (Decrease) Newly identified TDRs Financing Receivable Troubled Debt Restructuring Additions Represents the amount of additions of financing receivables which were newly identified as troubled debt restructurings. Balance at end of the period Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Non-Vested Stock Awards Outstanding Restricted Stock [Member] Stock Options Outstanding Employee Stock Option [Member] Stock-based compensation plans Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Non-vested Stock Awards Outstanding, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Balance at the beginning of the period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Stock awards vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Balance at the end of the period (in shares) Non-vested Stock Awards Outstanding, Weighted-Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Balance at the beginning of the period (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 Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Stock awards vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Balance at the end of the period (in dollars per share) Stock Options Outstanding, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Balance at the beginning of the period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Stock options exercised (in shares) Expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Balance at the end of the period (in shares) Exercisable options at the end of the period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Stock Options Outstanding, Weighted-Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Balance at the beginning of the period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Stock options exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Expired (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Balance at the end of the period (in dollars per share) Exercisable options at the end of the period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Organization, Consolidation and Presentation of Financial Statements [Abstract] BASIS OF PRESENTATION Business Description and Basis of Presentation [Text Block] Banking and Thrift, Interest [Abstract] Schedule of Net Interest Income After Provision for Loan Losses Interest Income and Interest Expense Disclosure [Table Text Block] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Carrying Amount Reported Value Measurement [Member] Total Fair Value Estimate of Fair Value Measurement [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Estimated fair values of financial instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Assets Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Trading security, at fair value Trading Securities Securities available for sale and other Available-for-sale Securities Securities held to maturity Held-to-maturity Securities, Fair Value FHLB bank stock and restricted securities Federal Home Loan Bank Stock and Other Restricted Securities at Cost This element represent as Federal Home Loan Bank Stock And Other Restricted Securities. Net loans Loans Receivable, Fair Value Disclosure Loans held for sale Loans Held-for-sale, Fair Value Disclosure Accrued interest receivable Interest Receivable Cash surrender value of bank-owned life insurance policies Cash Surrender Value, Fair Value Disclosure Derivative assets Derivative Asset, Fair Value, Gross Asset Assets held for sale Disposal Group, Including Discontinued Operation, Assets Financial Liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Total deposits Deposits, Fair Value Disclosure Short-term debt Short-term Debt, Fair Value Long-term Federal Home Loan Bank advances Federal Home Loan Bank Borrowings, Fair Value Disclosure Subordinated borrowings Subordinated Debt Obligations, Fair Value Disclosure Derivative liabilities Derivative Liability, Fair Value, Gross Liability Deposits [Abstract] DEPOSITS Deposit Liabilities Disclosures [Text Block] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Commercial Loan Commercial Loan [Member] Mortgages Mortgages [Member] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Pass Pass [Member] Special mention Special Mention [Member] Substandard Substandard [Member] Doubtful Doubtful [Member] Performing Performing Financial Instruments [Member] Nonperforming Nonperforming Financial Instruments [Member] Non Accrual Non Accrual [Member] Represents the category of financing receivables considered to be non-accrual. Classified Classified [Member] Represents the category of financing receivables considered to be classified. Criticized Criticized [Member] Credit quality information Financing Receivable, Recorded Investment [Line Items] Total Loans Loans and Leases Receivable, Net of Deferred Income Derivative Instruments and Hedging Activities Disclosure [Abstract] Offsetting Liabilities [Table] Offsetting Liabilities [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Interest Rate Swap [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Institutional counterparties Institutional Counterparties [Member] Represents information pertaining to the institutional counterparties. Commercial counterparties Commercial Counterparties [Member] Represents information pertaining to the commercial counterparties. Offsetting Liabilities [Line Items] Offsetting Liabilities [Line Items] Offsetting of Financial Liabilities and Derivative Liabilities Offsetting Derivative Liabilities [Abstract] Gross amounts of recognized liabilities Gross amounts offset in the Statements of Condition Derivative Liability, Fair Value, Gross Asset Net amounts of liabilities presented in the Statements of Condition Derivative Liability Gross amounts not offset in the Statements of Condition, financial instruments Derivative Liability, Not Offset, Policy Election Deduction Gross amounts not offset in the Statements of Condition, cash collateral pledged Derivative, Collateral, Right to Reclaim Cash Net amount Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election STOCK-BASED COMPENSATION PLANS Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Offsetting Assets [Table] Offsetting Assets [Table] Offsetting Assets [Line Items] Offsetting Assets [Line Items] Offsetting of Financial Assets and Derivative Assets Offsetting Derivative Assets [Abstract] Gross amounts of recognized assets Gross amounts offset in the Statements of Condition Derivative Asset, Fair Value, Gross Liability Net amounts of assets presented in the Statements of Condition Derivative Asset Gross amounts not offset in the Statements of Condition, financial instruments Derivative Asset, Not Offset, Policy Election Deduction Gross amounts not offset in the Statements of Condition, cash collateral received Derivative, Collateral, Obligation to Return Cash Net amount Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Earnings Per Share [Abstract] Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] Balance at beginning of period Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Reclassification from nonaccretable difference for loans with improved cash flows Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference Change in cash flows that do not affect nonaccretable difference Certain Loans Acquired in Transfer not Accounted for as Debt Securities Changes in Cash Flow not Affecting Nonaccretable Difference Certain Loans Acquired in Transfer not Accounted for as Debt Securities Changes in Cash Flow not Affecting Nonaccretable Difference Accretion Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion Balance at end of period Available for sale, Amortized Cost Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Rolling Maturity [Abstract] Within 1 year Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis Over 1 year to 5 years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis Over 5 years to 10 years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis Over 10 years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis Total bonds and obligations Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Mortgage-backed securities Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis Available-for-sale debt securities, amortized cost basis Available-for-sale Debt Securities, Amortized Cost Basis Available for sale, Fair Value Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity [Abstract] Within 1 year Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Over 1 year to 5 years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Over 5 years to 10 years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Over 10 years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value Total bonds and obligations Available-for-sale Securities, Debt Maturities, Single Maturity Date Mortgage-backed securities Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value Available for sale securities Available-for-sale Securities, Debt Securities Held to maturity, Amortized Cost Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Rolling Maturity [Abstract] Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Rolling Maturity [Abstract] Within 1 year Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments, maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. Over 1 year to 5 years Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments, maturing in the second through fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. Over 5 years to 10 years Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments, maturing in the sixth through tenth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. Over 10 years Held-to-maturity Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments, maturing after the tenth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. Total bonds and obligations Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Mortgage-backed securities Held-to-maturity Securities, Debt Maturities, without Single Maturity Date, Net Carrying Amount Held to maturity, amortized cost basis Held-to-maturity Securities Held to maturity, Fair Value Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturity [Abstract] Within 1 year Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Over 1 year to 5 years Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Over 5 years to 10 years Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Over 10 years Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Fair Value Total bonds and obligations Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value Total bonds and obligations Held-to-maturity Securities, Debt Maturities, without Single Maturity Date, Fair Value Fair Value Fair Value, Option, Quantitative Disclosures [Table] Fair Value, Option, Quantitative Disclosures [Table] Loans Held for Sale Loans Held For Sale [Member] Represents the details pertaining to loans held for sale. Loans Held for Sale Fair Value, Option, Quantitative Disclosures [Line Items] Fair Value Available-for-sale Securities, Equity Securities Amortized Cost Available-for-sale Equity Securities, Amortized Cost Basis Gains Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Aggregate Unpaid Principal Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Total commercial loans Commercial Portfolio Segment [Member] 1-4 Family Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Modifications that subsequently defaulted, number of contracts Financing Receivable, Modifications, Subsequent Default, Number of Contracts Modifications that subsequently defaulted, recorded investment Financing Receivable, Modifications, Subsequent Default, Recorded Investment Summary of Time Deposits Schedule of Time Deposits [Table Text Block] Tabular disclosure of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts. Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Unvested Stock Award shares Options Anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Securities excluded from the earnings per share calculations (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Document and Entity Information Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Non-recurring Fair Value, Measurements, Nonrecurring [Member] Summary of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis Segregated by the Level of the Valuation Inputs Within the Fair Value Hierarchy Utilized to Measure Fair Value Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Summary of securities available for sale Marketable Securities [Table Text Block] Schedule of Loans Held for Sale Fair Value, Option, Quantitative Disclosures [Table Text Block] Schedule of Changes in Level 3 Assets and Liabilities That Were Measured at Fair Value on a Recurring Basis Fair Value Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation [Table Text Block] Tabular disclosure of the fair value measurement of assets and liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset and liabilities. Schedule of Quantitative Information About the Significant Unobservable Inputs Within Level 3 Fair Value Inputs, Assets, Quantitative Information [Table Text Block] Summary of Applicable Non-Recurring Fair Value Measurements Fair Value Measurements, Nonrecurring [Table Text Block] Summary of Estimated Fair Values, and Related Carrying Amounts, of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] BORROWED FUNDS Debt Disclosure [Text Block] Schedule of Earnings Per Share Basic and Diluted [Table] Schedule of Earnings Per Share Basic and Diluted [Table] Disclosure pertaining to the entity's basic and diluted earnings per share. Earnings per share Earnings Per Share Basic and Diluted [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Net income Average number of common shares issued (in shares) Weighted Average Number of Shares Issued, Basic Less: average number of treasury shares (in shares) Weighted Average Number of Shares, Treasury Stock Less: average number of unvested stock award shares (in shares) Weighted Average Number of Shares, Restricted Stock Plus: average participating preferred shares (in shares) Weighted Average Number of Shares Outstanding, Preferred Stock Weighted Average Number of Shares Outstanding, Preferred Stock Average number of basic common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Plus: dilutive effect of share-based payment arrangements (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Average number of diluted common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Earnings per share: Earnings Per Share, Basic and Diluted [Abstract] Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Advances from the FHLB Federal Home Loan Bank Certificates and Obligations (FHLB) [Member] Federal Reserve Bank Advances Federal Reserve Bank Advances [Member] Federal Home Loan Bank Certificates And Obligations F H L B Amortizing Advances Federal Home Loan Bank Certificates And Obligations F H L B Amortizing Advances [Member] Represents information pertaining to federal home loan bank (FHLB) amortizing advances. Subordinated borrowings Private Placement Subordinated Notes [Member] Represents information pertaining to the private placement fixed and floating rate junior subordinated notes. Junior subordinated borrowings Junior Subordinated Debt [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Three-month LIBOR rate Debt Instrument Variable Rate Three Month L I B O R [Member] Represents the three-month London Interbank Offered Rate used to calculate the variable interest rate of the debt instrument. LIBOR London Interbank Offered Rate (LIBOR) [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Trust I Berkshire Hills Capital Trust I [Member] Represents information pertaining to Berkshire Hills Capital Trust I. Line of credit, current Line of Credit, Current Long-term line of credit Long-term Line of Credit Short-term debt Short-term Debt Long-term borrowings Long-term Debt Maturity period (in years) Debt Instrument, Term Principal amount of debt issued Debt Instrument, Face Amount Discount rate (as a percent) Debt Instrument, Issuance Discount Rate Represents the discount rate at the issuance of the debt instrument. Fixed interest rate (as percent) Debt Instrument, Interest Rate, Stated Percentage Maturity period with fixed interest rate (in months) Debt Instrument Fixed Interest Term Represents the period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, bearing fixed interest rate. Interest rate margin (as percent) Debt Instrument, Basis Spread on Variable Rate Unamortized debt issuance expense Unamortized Debt Issuance Expense Common stock of trust (as percent) Common Stock of Trust Held, Percentage Represents the percentage of common stock of a trust held by the entity. Common stock of trust included in other asset Common Stock of Trust Held Value Represents the amount of common stock of a trust held by the entity. Sole asset of trust in form of debt Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust Variable interest rate (as percent) Debt Instrument, Interest Rate, Effective Percentage Period up to which interest payments can be deferred (in years) Interest Payment Deferment Period Represents the period up to which the interest payments may be deferred. Time less than $100,000 Time Deposits, Less than $100,000 Time $100,000 through $250,000 Time Deposits, $100,000 Through $250,00 Time Deposits, $100,000 Through $250,00 Time more than $250,000 Time Deposits, $100,000 or More Total time deposits Time Deposits Brokered time deposits Brokered Time Deposits Represents the amount of time deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities. Reciprocal deposits Reciprocal Money Market Deposits Represents the reciprocal deposits. Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Non-interest income (in-scope of Topic 606) Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Non-interest income (out-of-scope of Topic 606) Calculated under Revenue Guidance in Effect before Topic 606 [Member] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Service charges on deposit accounts Service Charges [Member] Service Charges [Member] Insurance revenue Insurance Revenue [Member] Insurance Revenue [Member] Wealth management fees Wealth Management Fees [Member] Wealth Management Fees [Member] Interchange income Interchange Income [Member] Interchange Income [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Non-interest income Noninterest Income Investment Holdings [Table] Investment Holdings [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Municipal bonds and obligations US States and Political Subdivisions Debt Securities [Member] Agency collateralized mortgage obligations Collateralized Debt Obligations [Member] Agency mortgage-backed securities Residential Mortgage Backed Securities [Member] Agency commercial mortgage-backed securities Commercial Mortgage Backed Securities [Member] Tax advantaged economic development bonds Tax Advantaged Economic Development Bonds [Member] Represents the information pertaining to the tax advantaged economic development bonds. Corporate bonds Corporate Bond Securities [Member] Trust preferred securities Trust Preferred Securities Subject to Mandatory Redemption [Member] Other bonds and obligations Other Debt Obligations [Member] Investment Holdings [Line Items] Investment Holdings [Line Items] Available-for-sale Debt Securities, Amortized Cost Basis [Abstract] Available-for-sale Debt Securities, Amortized Cost Basis [Abstract] Available-for-sale debt securities, accumulated gross unrealized gain Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-sale debt securities, accumulated gross unrealized loss Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale securities, debt securities Available-for-sale Equity Securities, Amortized Cost Basis [Abstract] Available-for-sale Equity Securities, Amortized Cost Basis [Abstract] Available-for-sale equity securities, amortized cost basis Available-for-sale equity securities, accumulated gross unrealized gain Available-for-sale equity securities, accumulated gross unrealized loss Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale securities, equity securities Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract] Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract] Available-for-sale securities, amortized cost basis Available-for-sale Securities, Amortized Cost Basis Available-for-sale securities, accumulated gross unrealized gain Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-sale securities, accumulated gross unrealized loss Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Available for sale securities Securities held to maturity Held-to-maturity Securities [Abstract] Held to maturity securities accumulated unrecognized holding gains Held-to-maturity Securities, Accumulated Unrecognized Holding Gain Held to maturity securities, accumulated unrecognized holding loss Held-to-maturity Securities, Accumulated Unrecognized Holding Loss Securities held to maturity, fair value Available-for-sale Securities and Held-to-maturity Securities [Abstract] Available-for-sale Securities and Held-to-maturity Securities [Abstract] Held to maturity and available for sale securities, amortized cost basis Held To Maturity and Available For Sale Securities, Amortized Cost Represents the cost of debt and equity securities, which are categorized as held-to-maturity and available-for-sale, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. Held to maturity and available for sale securities, gross unrealized gain Held To Maturity and Available For Sale Securities, Gross Unrealized Gain Represents the gross unrealized gains for securities, at a point in time, which are categorized as held-to-maturity and available-for-sale securities. Held to maturity and available for sale securities, gross unrealized loss Held To Maturity and Available For Sale Securities, Gross Unrealized Losses Represents the gross unrealized losses for securities, at a point in time, which are categorized as held-to-maturity and available-for-sale securities. Held to maturity and available for sale securities, fair value Available-for-sale Securities and Held-to-maturity Securities Stockholders' Equity Note [Abstract] Schedule of Actual and Required Capital Ratios Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Schedule of Components of Accumulated Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Components of Other Comprehensive Income Comprehensive Income (Loss) [Table Text Block] Schedule of Gross Changes in Each Component of Accumulated Other Comprehensive Income Schedule of Changes in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Tabular disclosure of the changes in components of accumulated other comprehensive income (loss). Schedule of Amounts Reclassified Out of Each Component of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Number of securities in the portfolio (security) Investment Portfolio Number of Securities Represents the number of securities in the entity's security portfolio. Gains (losses) in fair value of loans held for sale included in earnings Fair Value, Option, Changes in Fair Value, Gain (Loss) Junior subordinated debentures re-price period (in days) Junior Subordinated Debentures Re-price Period Represents the re-price period of junior subordinated debentures. Accumulated other comprehensive (loss)/income Net unrealized holding loss on AFS securities Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Net unrealized loss on cash flow hedging derivatives Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Net unrealized holding loss on pension plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Other accumulated comprehensive income (loss), before tax AOCI before Tax, Attributable to Parent Income taxes related to items of accumulated other comprehensive income AOCI Tax, Attributable to Parent Total shareholders’ equity Schedule of Activity in the Allowance for Loan Losses Allowance for Credit Losses on Financing Receivables [Table Text Block] Schedule of Loans by Risk Rating Financing Receivable Credit Quality Indicators [Table Text Block] Summary of Information About Total Loans Rated Special Mention or Lower Schedule of Financing Receivable Rated Special Mention or Lower [Table Text Block] Tabular disclosure of financing receivables, rated as special mention or lower. Derivative [Table] Derivative [Table] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Economic hedges Economic Hedging [Member] Represents information pertaining to derivatives that are not designated as accounting hedges but are being used as economic hedges. Cash flow hedges Cash Flow Hedging [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Risk participation agreements with dealer banks Risk Participation Agreements [Member] Represents the information pertaining to risk participation agreements with dealer banks. Forward sale commitments Forward Commitments [Member] Represents the forward commitments that are free-standing derivatives which are carried at fair value with changes recorded in the mortgage banking component of noninterest income in the entity's consolidated statements of income. Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] FHLB borrowings Federal Home Loan Bank Borrowings [Member] Tax advantaged economic development bonds Nontaxable Municipal Bonds [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Amount Reclassified From Accumulated Other Comprehensive Income (loss) Reclassification out of Accumulated Other Comprehensive Income [Member] Accumulated net gain (loss) from cash flow hedges Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member] Derivative [Line Items] Derivative [Line Items] Notional amount Derivative, Notional Amount Cash collateral pledged Amortized cost of securities pledged as collateral to derivative counterparties Derivative Securities Pledged as Collateral Amortized Cost Represents the amortized cost of securities that are pledged as collateral to the derivative counterparties. Fair value of securities as pledged collateral to derivative counterparties Financial Instruments, Owned and Pledged as Collateral, at Fair Value Number of instruments (contract) Derivative, Number of Instruments Held Durations of derivative instruments (in years) Derivative, Term of Contract Interest expense Interest Expense Amount of ineffectiveness Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness Fixed rate of interest (as percent) Derivative, Fixed Interest Rate Credit valuation adjustments Derivative, Credit Risk Valuation Adjustment Derivative Assets (Liabilities) Net Amount of credit risk valuation adjustments to the net of derivative assets (derivative liabilities) to properly reflect the credit quality of the counterparties. Net asset position Derivative Asset, Fair Value, Amount Offset Against Collateral Derivative liability Amount of collateral posted for the net liability positions Collateral Already Posted, Aggregate Fair Value Basis of Presentation Consolidation, Policy [Policy Text Block] Reclassifications Reclassification, Policy [Policy Text Block] Prior Period Acquisition Business Combinations Policy [Policy Text Block] Recently Adopted Accounting Principles and Future Application of Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Fair Value Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation [Table] Schedule of information required and determined to be provided for purposes of reconciling beginning and ending balances of fair value measurements of assets and liabilities using significant unobservable inputs (level 3). Such reconciliation, separately presenting changes during the period, at a minimum, may include, but is not limited to: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income, and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset and liabilities. Commitments to lend Changes in Level 3 assets and liabilities that were measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Changes in Level 3 assets that were measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance at the beginning of the period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Unrealized (loss) gain, net recognized in other non-interest income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Paydown of trading security Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Additions to servicing rights Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, (Sales), Issuances, (Settlements) Balance at the end of the period Unrealized gains (losses) relating to instruments still held at the end of the period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Related to Assets Still Held This element represents the total unrealized net gains included in net income related to assets still held as of the balance sheet date. Derivative Asset (Liability) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Beginning balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Unrealized (loss) gain, net recognized in other non-interest income Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Transfers to held for sale loans Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers to Loans and Leases Held for Sale Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers to Loans and Leases Held for Sale Ending balance Number of Modifications Financing Receivable, Modifications, Number of Contracts Pre-Modification Outstanding Recorded Investment Financing Receivable, Modifications, Pre-Modification Recorded Investment Post-Modification Outstanding Recorded Investment Financing Receivable, Modifications, Post-Modification Recorded Investment Schedule of Loans Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Schedule of Activity in the Accretable Yield for the Acquired Loan Portfolio that Falls Under the Review of ASC 310-30, Accounting for Certain Loans or Debt Securities Acquired in a Transfer Schedule of Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Accretable Yield Movement [Table Text Block] Tabular disclosure of changes in accretable yield for purchased credit impaired finance receivables by way of additions, accretion, reclassifications and disposals during the period. Summary of Past Due Loans Past Due Financing Receivables [Table Text Block] Summary of Information Pertaining to Non-Accrual Loans Schedule of Financing Receivables, Non Accrual Status [Table Text Block] Schedule of Loans Evaluated for Impairment Schedule of Loans Evaluated for Impairment [Table Text Block] Tabular disclosure related to loans evaluated for impairment. Summary of Impaired Loans Impaired Financing Receivables [Table Text Block] Summary of the Average Recorded Investment and Interest Income Recognized on Impaired Loans Impaired Financing Receivables Average Balances and Related Interest Income Recognized [Table Text Block] Tabular disclosure of average recorded investment in impaired loans and related interest income recognized for the periods indicated. Schedule of Recorded Investment and Number of Modifications for TDRs Identified During the Period Troubled Debt Restructurings on Financing Receivables [Table Text Block] Schedule of TDR Activity Financing Receivable Troubled Debt Restructuring Activity [Table Text Block] Tabular disclosure of activity of troubled debt restructuring financial receivables. CAPITAL RATIOS AND STOCKHOLDERS' EQUITY Stockholders' Equity Note Disclosure [Text Block] Summary of Activity in the Stock Award and Stock Option Plans Share-based Compensation, Activity [Table Text Block] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Domain] Financing Receivables, Period Past Due [Domain] 30-59 Days Past Due Financing Receivables, 30 to 59 Days Past Due [Member] 60-89 Days Past Due Financing Receivables, 60 to 89 Days Past Due [Member] 90 Days or Greater Past Due Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Financing Receivable, Recorded Investment, Past Due [Line Items] Total Past Due Financing Receivable, Recorded Investment, Past Due Current Financing Receivable, Recorded Investment, Current Acquired Credit Impaired Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net Total loans Past Due 90 days and Accruing Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing Total loans Certain loans acquired in transfer not accounted for as debt securities, note balance, net Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Note Balance, Net Represents the note balance amount of loans, considered impaired, at the time of acquisition. Financing receivable not considered impaired at time of acquisition Financing Receivable Not Considered Impaired at Time of Acquisition Represents the carrying amount of loans, not considered impaired, at the time of acquisition. Borrower's sustained repayment performance period Troubled Debt Restructuring, Sustained Repayment Period of Borrower to Consider Return to Performing Status Represents the reasonable period of a borrower's sustained repayment performance for consideration of returning the loan to performing status. Process of foreclosure Securities Received as Collateral, Amount Foreclosed Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Realized gains on AFS securities: Realized (losses) on cash flow hedging derivatives: Realized gains on pension plans: Amounts reclassified out of each component of accumulated other comprehensive income Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Interest expense Non-interest expense Noninterest Expense Tax (expense) benefit Income Tax Expense (Benefit) Net income Net Income (Loss) Available to Common Stockholders, Basic Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Bank Subsidiaries [Member] Tier 1 capital to risk-weighted assets Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Total capital to risk weighted assets Capital to Risk Weighted Assets Common equity tier 1 capital to risk weighted assets Common Equity Tier One Risk Based Capital to Risk Weighted Assets Common equity Tier 1 capital divided by risk weighted assets as defined by regulations. Tier 1 capital to risk weighted assets Tier One Risk Based Capital to Risk Weighted Assets Tier 1 capital to average assets Tier One Leverage Capital to Average Assets Regulatory minimum to be well capitalized, Total capital to risk weighted assets (as percent) Capital Required to be Well Capitalized to Risk Weighted Assets Regulatory minimum to be well capitalized, Common equity tier 1 capital to risk weighted assets (as percent) Common Equity Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets The Common equity Tier 1 capital ratio (Common equity Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. Regulatory minimum to be well capitalized, Tier 1 capital to risk weighted assets (as percent) Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Regulatory minimum to be well capitalized, Tier 1 capital to average assets (as percent) Tier One Leverage Capital Required to be Well Capitalized to Average Assets Advances from the FHLB Short-term borrowings Total borrowings Debt and Capital Lease Obligations Weighted average rate on short-term borrowings (as percent) Short-term Debt, Weighted Average Interest Rate, at Point in Time Weighted average rate on long-term borrowings (as percent) Long-term Debt, Weighted Average Interest Rate, at Point in Time Weighted average rate (as percent) Debt, Weighted Average Interest Rate Total cash flow hedges Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest Expense Interest Expense [Member] Other non-interest expense Other Non-interest Expense [Member] Other Non-interest Expense [Member] Unrealized (loss) recognized in accumulated other comprehensive loss Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss) Less: reclassification of unrealized (loss) from accumulated other comprehensive income to interest expense Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Net tax (expense) benefit on items recognized in accumulated other comprehensive income Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Other comprehensive gain (loss) recorded in accumulated other comprehensive income, net of reclassification adjustments and tax effects Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Reverse interest rate swaps Reverse Interest Rate Swaps [Member] Represents information pertaining to the reverse interest rate swaps which can be used to synthetically convert fixed rate debt to floating. Non-hedging derivatives Nonhedging [Member] Represents information pertaining to derivatives that are not used for hedging purposes and thus are not designated as accounting hedges. Industrial revenue bond Industrial Revenue Bond [Member] Represents information pertaining to the industrial revenue bond, a financing instrument issued by designated local industrial development boards (IDB's) or other issuers authorized by state law. Loans with commercial loan customers Commercial Paper [Member] Unrealized gain recognized in other non-interest income Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments (Unfavorable) Favorable change in credit valuation adjustment recognized in other non-interest income Derivative Instruments Favorable Changes in Credit Valuation Adjustment Recognized in Other Non Interest Income The favorable changes in credit valuation adjustments on derivative instruments that were recognized in other non-interest income during the current period. Realized gain (loss) in other non-interest income Gain (Loss) on Sale of Derivatives Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Allowance for loan losses Financing Receivable, Allowance for Credit Losses [Line Items] Loans receivable: balance at end of period Loans and Leases Receivable, Other Information [Abstract] Individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Purchased credit-impaired loans Financing Receivable, Purchased Credit-Impaired Loans Financing Receivable, Purchased Credit-Impaired Loans Collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Statement of Financial Position [Abstract] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series B Convertible Preferred Stock Convertible Preferred Stock [Member] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Treasury stock (in shares) Treasury Stock, Shares Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Provision for loan losses Provision for Loan and Lease Losses Net amortization of securities Accretion (Amortization) of Discounts and Premiums, Investments Change in unamortized net loan costs and premiums Change in Unamortized Net Loan Costs and Premiums This element represent as Change In Unamortized Net Loan Costs And Premiums. Premises and equipment depreciation and amortization expense Depreciation, Depletion and Amortization, Nonproduction Stock-based compensation expense Share-based Compensation Accretion of purchase accounting entries, net Amortization Amortization of other intangibles Amortization of Intangible Assets Income from cash surrender value of bank-owned life insurance policies Bank Owned Life Insurance Income Securities losses (gains), net Marketable Securities, Realized Gain (Loss) Originations of loans held for sale Increase (Decrease) in Loans Held-for-sale Proceeds from sale of loans held for sale Proceeds from Sale of Loans Held-for-sale Net gain on sale of loans and other mortgage banking income Gain (Loss) In Change Of Fair Value Of Loans Held For Sale Gain (Loss) In Change Of Fair Value Of Loans Held For Sale Loss on disposition of assets Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Loss on sale of real estate Gains (Losses) on Sales of Other Real Estate Amortization of interest in tax-advantaged projects Amortization of Tax Credits Represent the information pertaining to amortization of tax credits Net change in other Other Noncash Income (Expense) Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Net decrease in trading security Increase (Decrease) in Trading Securities Proceeds from sales of securities available for sale Proceeds from Sale of Available-for-sale Securities Proceeds from maturities, calls, and prepayments of securities available for sale Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Purchases of securities available for sale and other Payments to Acquire Available-for-sale Securities Purchases of marketable equity securities Payments to Acquire Available-for-sale Securities, Equity Proceeds from sales of marketable equity securities Proceeds from Sale of Available-for-sale Securities, Equity Proceeds from maturities, calls, and prepayments of securities held to maturity Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Purchases of securities held to maturity Payments to Acquire Held-to-maturity Securities Net change in loans Payments for (Proceeds from) Loans and Leases Proceeds from surrender of bank-owned life insurance Proceeds from Life Insurance Policy Proceeds from sale of Federal Home Loan Bank stock Proceeds from Sale of Federal Reserve Bank Stock Purchase of Federal Home Loan Bank stock Payments to Acquire Federal Reserve Bank Stock Net investment in limited partnership tax credits Payments for (Proceeds from) Other Investing Activities Purchase of premises and equipment, net Payments to Acquire Property, Plant, and Equipment Payment to terminate cash flow hedges Payments for (Proceeds from) Derivative Instrument, Investing Activities Proceeds from sale of other real estate Proceeds from Sale of Other Real Estate Net cash (used) by investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Net (decrease) increase in deposits Increase (Decrease) in Deposits Proceeds from Federal Home Loan Bank advances and other borrowings Proceeds from Issuance of Long-term Debt Repayments of Federal Home Loan Bank advances and other borrowings Repayments of Long-term Debt Exercise of stock options Proceeds from Stock Options Exercised Common and preferred stock cash dividends paid Payments of Ordinary Dividends, Common Stock Acquisition contingent consideration paid Payment for Contingent Consideration Liability, Financing Activities Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Net change in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and Cash Equivalents, at Carrying Value, Including Discontinued Operations Cash and cash equivalents at end of period Supplemental cash flow information: Supplemental Cash Flow Information [Abstract] Interest paid on deposits Interest Paid on Deposits This element represent as Interest Paid On Deposits. Interest paid on borrowed funds Interest Paid Income taxes paid (refund), net Income Taxes Paid, Net Other non-cash changes: Other Noncash Investing and Financing Items [Abstract] Other net comprehensive income Real estate owned acquired in settlement of loans Real Estate Owned Acquired in Settlement of Loans Represents the value of real estate acquired in settlement of loans through non cash transactions. Average recorded investment, with no related allowance Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Cash basis interest income recognized, with no related allowance Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method Average recorded investment with related allowance Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Cash basis interest income recognized, with related allowance Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method Average recorded investment Impaired Financing Receivable, Average Recorded Investment Interest income, cash basis method Impaired Financing Receivable, Interest Income, Cash Basis Method Common stock, cash dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Preferred stock, cash dividends declared (in dollars per share) Preferred Stock, Dividends Per Share, Declared New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Increase in AOCI Accumulated Other Comprehensive Income (Loss), Net of Tax Decrease in retained earnings Retained Earnings (Accumulated Deficit) Summary of securities available for sale (AFS) and held to maturity Schedule of amortized cost and estimated fair value of available for sale (AFS) and held to maturity (HTM) securities, segregated by contractual maturity Investments Classified by Contractual Maturity Date [Table Text Block] Schedule of securities with unrealized losses, segregated by the duration of their continuous unrealized loss positions Schedule of Unrealized Loss on Investments [Table Text Block] Income Statement [Abstract] Interest and dividend income Interest and Dividend Income, Operating [Abstract] Loans Interest and Fee Income, Loans and Leases Securities and other Interest and Dividend Income, Securities, Operating Total interest and dividend income Interest and Dividend Income, Operating Interest expense Interest Expense [Abstract] Deposits Interest Expense, Deposits Borrowings Interest Expense, Borrowings Total interest expense Net interest income Interest Income (Expense), Net Non-interest income Noninterest Income [Abstract] Mortgage banking originations Fees and Commissions, Mortgage Banking Loan related income Noninterest Income, Other Operating Income Deposit related fees Fees and Commissions, Depositor Accounts Insurance commissions and fees Insurance Commissions and Fees Wealth management fees Asset Management Fees Total fee income Fees and Commissions Other, net Noninterest Income, Other (Loss)/gain on securities, net Gain (Loss) on Sale of Securities, Net Gain on sale of business operations and other assets, net Gain (Loss) on Disposition of Business Loss on termination of hedges Gain Loss on Termination of Derivative Instruments Designated as Hedging Instruments Represents the amount of gain (loss) recorded during the reporting period related to termination of hedging derivative instruments. Total non-interest income Total net revenue Revenues Non-interest expense Noninterest Expense [Abstract] Compensation and benefits Labor and Related Expense Occupancy and equipment Occupancy and Equipment This element represent as Occupancy And Equipment. Technology and communications Communications and Information Technology Marketing and promotion Marketing Expense Professional services Professional Fees FDIC premiums and assessments Federal Deposit Insurance Corporation Premium Expense Other real estate owned and foreclosures Other Real Estate Owned This element represent as Other Real Estate Owned. Amortization of intangible assets Acquisition, restructuring, and other expenses Other Nonrecurring Expense Other Other Noninterest Expense Total non-interest expense Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Net income Preferred stock dividend Preferred Stock Dividends, Income Statement Impact Income available to common shareholders Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Diluted (in shares) Assets Assets [Abstract] Cash and due from banks Cash and Due from Banks Short-term investments Cash Equivalents, at Carrying Value Total cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Securities available for sale and other, at fair value Securities held to maturity (fair values of $394,296 and $405,276) Federal Home Loan Bank stock and other restricted securities Total securities Investments Loans held for sale, at fair value Loans Receivable Held-for-sale, Net, Not Part of Disposal Group or Discontinued Operation Amount of loans held for sale, including but not limited to, commercial and consumer loans. Excludes loans not part of a disposal group or discontinued operation. Commercial real estate Loans Receivable, Gross, Commercial, Real Estate Commercial and industrial loans Loans Receivable, Gross, Commercial and Industrial Residential mortgages Loans and Leases Receivable, Gross, Consumer, Mortgage Consumer loans Loans and Leases Receivable, Gross, Consumer, Real Estate Less: Allowance for loan losses Loans and Leases Receivable, Allowance Net loans Loans and Leases Receivable, Net Amount Premises and equipment, net Property, Plant and Equipment, Net Goodwill Goodwill Other intangible assets Intangible Assets, Net (Excluding Goodwill) Cash surrender value of bank-owned life insurance policies Bank Owned Life Insurance Deferred tax assets, net Deferred Tax Assets, Net Other assets Other Assets Total assets Assets Liabilities Liabilities [Abstract] Demand deposits Demand Deposit Accounts NOW and other deposits Deposits, Negotiable Order of Withdrawal (NOW) Money market deposits Deposits, Money Market Deposits Savings deposits Deposits, Savings Deposits Time deposits Total deposits Deposits Long-term Federal Home Loan Bank advances Long-term Federal Home Loan Bank Advances Subordinated borrowings Junior Subordinated Notes Other liabilities Other Liabilities Total liabilities Liabilities Shareholders’ equity Stockholders' Equity Attributable to Parent [Abstract] Preferred Stock (Series B non-voting convertible preferred stock - $0.01 par value; 1,000,000 shares authorized, 521,607 shares issued and outstanding in 2018; 1,000,000 shares authorized, 521,607 shares issued and outstanding in 2017 Preferred Stock, Value, Issued Common stock ($.01 par value; 50,000,000 shares authorized and 46,211,894 shares issued and 45,360,369 shares outstanding in 2018; 50,000,000 shares authorized, 46,211,894 shares issued and 45,290,433 shares outstanding in 2017) Common Stock, Value, Issued Additional paid-in capital - common stock Additional Paid in Capital, Common Stock Unearned compensation Deferred Compensation Equity Retained earnings Accumulated other comprehensive (loss) income Treasury stock, at cost (851,525 shares in 2018 and 921,461 shares in 2017) Treasury Stock, Value Total liabilities and shareholders’ equity Liabilities and Equity Impaired loans Impaired Loans, Fair Value Disclosure Represents the amount of impaired loans assets reported on the balance sheet at period end measured at fair value by the entity. Capitalized servicing rights Servicing Asset at Fair Value, Amount Total Assets, Fair Value Disclosure Designated as Hedging Instrument Designated as Hedging Instrument [Member] Total economic hedges Interest rate swap agreements and non-hedging derivative assets and liabilities Derivative Instrument Detail [Abstract] Weighted average maturity Derivative, Average Remaining Maturity Weighted average rate, received (as percent) Derivative, Weighted Average Rate, Received Represents information pertaining to the derivative weighted average rate which is received. Weighted average rate, contract pay rate (as percent) Derivative, Weighted Average Rate, Paid Represents information pertaining to the derivative weighted average rate which is paid. Estimated fair value asset (liability) Derivative Assets (Liabilities), at Fair Value, Net Debt securities Debt Securities [Member] Marketable equity securities Equity Securities [Member] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Agency collateralized mortgage obligations Collateralized Mortgage Obligations [Member] Agency residential mortgage-backed securities Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Capitalized servicing rights Schedule of Borrowed Funds Schedule of Debt [Table Text Block] Summary of Maturities of FHLBB Advances Schedule of Maturities and Weighted Average Interest Rates of Federal Home Loan Bank Advances [Table Text Block] Tabular disclosure of the contractual maturities and weighted average interest rates on borrowings or advances from Federal Home Loan Bank. Amortized cost Trading Securities, Cost Fair value Amount of other securities in the trading portfolio Trading Securities, Other NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES Interest Income and Interest Expense Disclosure [Text Block] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Impaired loans Financing Receivable, Impaired [Line Items] Recorded Investment Impaired Financing Receivable, Recorded Investment [Abstract] With no related allowance Impaired Financing Receivable, with No Related Allowance, Recorded Investment With an allowance recorded Impaired Financing Receivable, with Related Allowance, Recorded Investment Total Impaired Financing Receivable, Recorded Investment