Statement of Comprehensive Income [Abstract] Net income Net Income (Loss) Attributable to Parent Other comprehensive income, before tax: Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent [Abstract] Changes in unrealized loss on debt securities available-for-sale Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, before Tax Changes in unrealized loss on derivative hedges Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Income taxes related to other comprehensive income: Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract] Changes in unrealized loss on debt securities available-for-sale Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Changes in unrealized gains on derivative hedges Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Total other comprehensive (loss)/income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Deposits [Abstract] Summary of Time Deposits Schedule of Time Deposits [Table Text Block] Tabular disclosure of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required.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. Earnings Per Share [Abstract] 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 Restricted Stock [Member] Options Employee Stock Option [Member] 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 Income Statement [Abstract] Statement [Table] Statement [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Mortgage banking originations Mortgage Banking [Member] Loan related income Bank Servicing [Member] Deposit related fees Deposit Account [Member] Insurance commissions and fees Insurance Revenue [Member] Insurance Revenue [Member] Wealth management fees Asset Management Fees [Member] Asset Management Fees [Member] Total fee income Banking [Member] Statement [Line Items] Statement [Line Items] 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 Interest Expense Net interest income Interest Income (Expense), Net Non-interest income Noninterest Income [Abstract] Other, net Noninterest Income, Other (Loss)/gain on securities, net Debt and Equity Securities, Gain (Loss) (Loss)/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 Noninterest Income Total net revenue Revenues Provision for loan losses Provision for Loan and Lease Losses 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 Amortization of Intangible Assets Acquisition, restructuring, and other expenses Other Nonrecurring Expense Other Other Noninterest Expense Total non-interest expense Noninterest Expense Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Net income Preferred stock dividend Preferred Stock Dividends, Income Statement Impact Income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Earnings per common 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 Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted 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 Derivative Liability, Fair Value, Gross Liability 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 Investments, Debt and Equity Securities [Abstract] Investment Holdings [Table] Investment Holdings [Table] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [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] Corporate bonds Corporate Bond Securities [Member] Other bonds and obligations Other Debt Obligations [Member] Tax advantaged economic development bonds Tax Advantaged Economic Development Bonds [Member] Represents the information pertaining to the tax advantaged economic development bonds. Investment Holdings [Line Items] Investment Holdings [Line Items] Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] Available for sale securities, less than twelve months, gross unrealized losses Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Available for sale securities, over twelve months, gross unrealized losses Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Available for sale securities, continuous unrealized loss position, accumulated loss Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract] Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract] Available for sale securities, continuous unrealized loss position, less than twelve months, fair value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Available for sale securities, continuous unrealized loss position, over twelve months, fair value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Available for sale securities, continuous unrealized loss position, fair value Debt Securities, Available-for-sale, Unrealized Loss Position Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position [Abstract] Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position [Abstract] Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss [Abstract] Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss [Abstract] Held-to-maturity securities, continuous unrealized loss position, less than twelve months, accumulated loss Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Held-to-maturity securities, continuous unrealized loss position, over twelve months, gross unrealized losses Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Held to maturity securities, accumulated unrecognized holding loss Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract] Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract] Held to maturity securities, accumulated unrecognized holding loss, less than twelve months, fair value Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value Held to maturity securities, accumulated unrecognized holding loss, over twelve months, fair value Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value Held to maturity securities, accumulated unrecognized holding loss, fair value Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value Securities available for sale and held to maturity Available For Sale Securities and Held To Maturity Securities Continuous Unrealized Loss Position [Abstract] Held to maturity and available for sale securities continuous unrealized loss position, less than twelve months, aggregate losses Debt Securities, Available-for-sale and Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Represents the excess of amortized cost basis over the fair value of securities that have been in a loss position for less than twelve months for those securities that are categorized as held-to-maturity and available-for-sale. Held to maturity and available for sale securities continuous unrealized loss position, less than twelve months, fair value Debt Securities, Available-for-sale and Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months Represents the aggregate fair value of investments in debt and equity securities categorized as held-to-maturity and available-for-sale that have been in a continuous unrealized loss position for less than twelve months. Held to maturity and available for sale securities continuous unrealized loss position, over twelve months, aggregate losses Debt Securities, Available-for-sale and Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Represents the excess of amortized cost basis over the fair value of securities that have been in a loss position for twelve months or longer for those securities that are categorized as held-to-maturity and available-for-sale. Held to maturity and available for sale securities continuous unrealized loss position, over twelve months, fair value Debt Securities, Available-for-sale and Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer Represents the aggregate fair value of investments in debt and equity securities categorized as held-to-maturity and available-for-sale that have been in a continuous unrealized loss position for twelve months or longer. Held to maturity and available for sale securities continuous unrealized loss position, aggregate losses Debt Securities, Available-for-sale and Held-to-maturity, Unrealized Loss Position, Accumulated Loss Represents the excess of amortized cost basis over the fair value of securities that have been in a loss position, which are categorized as held-to-maturity and available-for-sale. Held to maturity and available for sale securities continuous unrealized loss position, fair value Debt Securities, Available-for-sale and Held-to-maturity, Unrealized Loss Position Represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized as held-to-maturity and available-for-sale securities. Receivables [Abstract] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] 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. 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 Consumer Portfolio Segment [Member] Allowance for loan losses Financing Receivable, Allowance for Credit Losses [Line Items] Activity in the allowance for loan losses Allowance for Loan and Lease Losses [Roll Forward] Balance at beginning of period Loans and Leases Receivable, Allowance Charged-off loans Allowance for Loan and Lease Losses, Write-offs Recoveries on charged-off loans Allowance for Loan and Lease Loss, Recovery of Bad Debts Provision/(releases) for loan losses Balance at end of period Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Total Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Summary of Activity in the Stock Award and Stock Option Plans Share-based Compensation, Activity [Table Text Block] DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES Derivative Instruments and Hedging Activities Disclosure [Text Block] LOANS Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2018-02 Accounting Standards Update 2018-02 [Member] Accounting Standards Update 2018-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Reclassification from AOCI Tax Cuts And Jobs Act Of 2017 Reclassification From Aoci To Retained Earnings Tax Effect Tax Cuts And Jobs Act Of 2017 Reclassification From Aoci To Retained Earnings Tax Effect Decrease in retained earnings Retained Earnings (Accumulated Deficit) 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. 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 Stock Options Outstanding 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) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period 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 STOCK-BASED COMPENSATION PLANS Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Commercial loans Commercial Portfolio Segment [Member] Commercial Real Estate Residential Mortgages Consumer Loans 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. Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Total Loans Loans and Leases Receivable, Net of Deferred Income Derivative [Table] Derivative [Table] 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] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Total cash flow hedges Cash Flow Hedging [Member] 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] Derivative [Line Items] Derivative [Line Items] 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 Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Total economic hedges Economic Hedging [Member] Represents information pertaining to derivatives that are not designated as accounting hedges but are being used as economic hedges. 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. 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. Commitments to lend Commitments to Extend Credit [Member] Tax advantaged economic development bonds Nontaxable Municipal Bonds [Member] Loans with commercial loan customers Commercial Paper [Member] Interest rate swap agreements and non-hedging derivative assets and liabilities Derivative Instrument Detail [Abstract] Notional amount Derivative, Notional Amount 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 1-4 Family 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 Cash Basis Interest Income Recognized Impaired Financing Receivable, Interest Income, Cash Basis Method Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Loans Held for Sale Loans Held For Sale [Member] Represents the details pertaining to loans held for sale. 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 trading 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. Stockholders' Equity Note [Abstract] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Realized gains on AFS securities: Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Realized (losses) on cash flow hedging derivatives: Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [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] Amounts reclassified out of each component of accumulated other comprehensive income Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Non-interest income Interest expense Non-interest expense Tax (expense) benefit Net income Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] 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 Amortized cost Debt Securities, Trading, Amortized Cost Trading security, at fair value Debt Securities, Trading 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 Derivative Asset, Fair Value, Gross Asset 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 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. Available for sale, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost, Rolling Maturity [Abstract] Within 1 year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost Over 1 year to 5 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost Over 5 years to 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Amortized Cost Over 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost Total bonds and obligations Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Mortgage-backed securities Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost Available-for-sale debt securities, amortized cost basis Debt Securities, Available-for-sale, Amortized Cost Available for sale, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract] Within 1 year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Over 1 year to 5 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Over 5 years to 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Fair Value Over 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value Total bonds and obligations Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value Mortgage-backed securities Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value Available for sale securities Debt Securities, Available-for-sale 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 Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost Mortgage-backed securities Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Amortized Cost Held to maturity, amortized cost basis Debt Securities, Held-to-maturity Held to maturity, Fair Value Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract] Within 1 year Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Over 1 year to 5 years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Over 5 years to 10 years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Fair Value Over 10 years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value Total bonds and obligations Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value Mortgage-backed securities Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Fair Value Fair Value Debt Securities, Held-to-maturity, Fair Value Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] 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] Banking and Thrift, Interest [Abstract] Schedule of Net Interest Income After Provision for Loan Losses Interest Income and Interest Expense Disclosure [Table Text Block] SECURITIES AVAILABLE FOR SALE, HELD TO MATURITY, AND MARKETABLE EQUITY SECURITIES Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] TRADING SECURITY Disclosure of Trading Securities and Certain Trading Assets [Text Block] The entire disclosure for trading securities. 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] Fair Value Estimate of Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [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 Debt Securities, Trading, and Equity Securities, FV-NI Marketable equity securities Equity Securities, FV-NI Securities available for sale Securities held to maturity 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 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 Statement of Stockholders' Equity [Abstract] 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] ASU 2016-01 Accounting Standards Update 2016-01 [Member] 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 Other comprehensive loss Common stock issued (in shares) Stock Issued During Period, Shares, New Issues Common stock issued Stock Issued During Period, Value, New Issues 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) 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 Summary of securities available for sale (AFS) and held to maturity Marketable Securities [Table Text Block] 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] Fair Value Option, Disclosures [Table] Fair Value Option, Disclosures [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Loans Held for Sale Fair Value, Option, Quantitative Disclosures [Line Items] Marketable equity securities, fair value Marketable equity securities, amortized cost Equity Securities, FV-NI, Cost Marketable equity securities, gains Equity Securities, FV-NI, Gain (Loss) Marketable equity securities, fair value Available-for-sale Securities, Equity Securities Marketable equity securities, amortized cost Available-for-sale Equity Securities, Amortized Cost Basis Marketable equity securities, 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 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] 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. Debt Instrument [Line Items] Debt Instrument [Line Items] 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. NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES Interest Income and Interest Expense Disclosure [Text Block] 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 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 Net interest income Net interest income after provision for loan losses Interest Income (Expense), after Provision for Loan Loss 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] Securities held to maturity, fair value 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 Revenue from Contract with Customer [Abstract] Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Total Fair Value Debt securities Debt Securities [Member] Marketable equity securities Equity Securities [Member] Agency collateralized mortgage obligations Collateralized Mortgage Obligations [Member] Agency residential mortgage-backed securities Trust preferred securities Trust Preferred Securities Subject to Mandatory Redemption [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Trading security Securities available for sale Capitalized servicing rights Servicing Asset at Fair Value, Amount 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] Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] 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] 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 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 Debt Securities, Trading, and Equity Securities, FV-NI 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 Debt Securities, Available-for-sale Purchases of securities available for sale Payments to Acquire Available-for-sale Securities Proceeds from sales of marketable equity securities Proceeds from Sale of Available-for-sale Securities, Equity Purchases of marketable equity securities Payments to Acquire 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 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 Common stock issued, net Proceeds from Issuance of 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, Including Capitalized Interest, Operating and Investing Activities 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. LOAN LOSS ALLOWANCE Allowance for Credit Losses [Text Block] 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 Mortgages Mortgages [Member] Total loans Acquired credit impaired Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net 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 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 Net unrealized holding gain (loss) Other Comprehensive Income (Loss) before Reclassifications [Abstract] Before Tax OCI, before Reclassifications, before Tax, Attributable to Parent Tax Effect Other Comprehensive Income (Loss) before Reclassifications, Tax Net of Tax OCI, before Reclassifications, Net of Tax, Attributable to Parent Less: reclassification adjustment for gains (losses) realized in net income Reclassification from Accumulated Other Comprehensive Income Current Period [Abstract] Before Tax Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Tax Effect Reclassification from AOCI, Current Period, Tax Net of Tax Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Before Tax Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Tax Effect Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Less: reclassification related to adoption of ASU Reclassification From AOCI, Accounting Standards Update [Abstract] Reclassification From AOCI, Accounting Standards Update [Abstract] Before Tax Reclassification From AOCI, Accounting Standards Update, Current Period, Before Tax, Attributable To Parent Reclassification From AOCI, Accounting Standards Update, Current Period, Before Tax, Attributable To Parent Tax Effect Reclassification From AOCI, Accounting Standards Update, Current Period, Tax Reclassification From AOCI, Accounting Standards Update, Current Period, Tax Net of Tax Reclassification From AOCI, Accounting Standards Update, Current Period, Net Of Tax, Attributable To Parent Reclassification From AOCI, Accounting Standards Update, Current Period, Net Of Tax, Attributable To Parent Total change to accumulated other comprehensive (loss) AOCI Attributable to Parent [Abstract] Before Tax Total Change To AOCI Before Tax, Attributable To Parent Total Change To AOCI Before Tax, Attributable To Parent Tax Effect Total Change To AOCI Tax, Attributable To Parent Total Change To AOCI Tax, Attributable To Parent Net of Tax Total Change To AOCI Net Of Tax, Attributable To Parent Total Change To AOCI Net Of Tax, Attributable To Parent Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Non-recurring Fair Value, Measurements, Nonrecurring [Member] Quantitative information about the significant unobservable inputs within Level 3 Fair Value Measurement Inputs and Valuation Techniques [Line Items] 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 Schedule of Loans Held for Sale Fair Value Option, 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 Measurement Inputs and Valuation Techniques [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] DEPOSITS Deposit Liabilities Disclosures [Text Block] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Number of grades in internal loan rating system (grade) Internal Loan Rating System Number of Grades The number of grades in the reporting entity's internal loan rating system. Delinquency period of loans based on which risk rating is assigned to loans (in days) Financing Receivable Risk Rating Delinquency Period Represents the delinquency period of loans based on which risk rating is assigned to loans. Period within which loans are current, based on which risk rating is assigned (in days) Financing Receivable Risk Rating Current Period Represents the current period of loans based on which risk rating is assigned to loans. Allowance for losses on acquired loans under Subtopic ASC 310-30 Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses 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. Weighted Average Weighted Average [Member] 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 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. 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] Revenue Revenue Recognition, Policy [Policy Text Block] 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 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 Total Assets, Fair Value Disclosure Debt securities: Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract] Available-for-sale debt securities, accumulated gross unrealized gain Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Available-for-sale debt securities, accumulated gross unrealized loss Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Available-for-sale securities, debt securities Securities held to maturity Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract] Held to maturity securities accumulated unrecognized holding gains Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Held to maturity securities, accumulated unrecognized holding loss Marketable equity securities, gross unrealized gains Equity Securities, FV-NI, Unrealized Gain Marketable equity securities, gross unrealized losses Equity Securities, FV-NI, Unrealized Loss Total, amortized cost basis Debt Securities, Available-for-sale and Held-to-maturity, and Equity Securities, FV-NI, 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. Total, gross unrealized gain Debt Securities, Available-for-sale and Held-to-maturity, and Equity Securities, FV-NI, Accumulated Gross Unrealized Gain, before Tax Represents the gross unrealized gains for securities, at a point in time, which are categorized as held-to-maturity and available-for-sale securities. Total, gross unrealized loss Debt Securities, Available-for-sale and Held-to-maturity, and Equity Securities, FV-NI, Accumulated Gross Unrealized Loss, before Tax Represents the gross unrealized losses for securities, at a point in time, which are categorized as held-to-maturity and available-for-sale securities. Total, fair value Debt Securities, Available-for-sale and Held-to-maturity, and Equity Securities, FV-NI Debt Securities, Available-for-sale and Held-to-maturity, and Equity Securities, FV-NI 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. BASIS OF PRESENTATION Business Description and Basis of Presentation [Text Block] 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 Marketable equity securities, at fair value Marketable Securities Securities available for sale, at fair value Available-for-sale Securities Securities held to maturity (fair values of $377,486 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 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 Total loans Less: Allowance for loan losses 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 - $0.01 par value; 2,000,000 shares authorized, 521,607 shares issued and outstanding in 2018; 1,000,000 shares authorized, 521,607 shares issued and outstanding in 2017 Preferred Stock, Value, Issued Common stock ($.01 par value; 100,000,000 shares authorized and 46,211,894 shares issued and 45,420,276 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 Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury stock, at cost (791,618 shares in 2018 and 921,461 shares in 2017) Treasury Stock, Value Total shareholders’ equity Total liabilities and shareholders’ equity Liabilities and Equity 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 Past Due 90 days and Accruing Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing Mortgage-backed securities Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Available-for-sale, securities in unrealized loss positions (security) Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions Available for sale securities portfolio, number of securities (security) Debt Securities. Available-for-sale, Number of Positions Represents the number of securities in the entity's portfolio of available-for-sale securities. Available for sale securities, continuous unrealized loss position, aggregate losses (as percent) Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Qualitative Disclosure, Aggregate Losses Percentage Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Qualitative Disclosure, Aggregate Losses Percentage Held to maturity securities, continuous unrealized loss position, aggregate losses (as percent) Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Qualitative Disclosure, Aggregate Losses Percentage Represents the aggregate unrealized losses, expressed as a percentage of the amortized cost of the securities in a continuous unrealized loss position categorized as held-to-maturity and available-for-sales securities. Held-to-maturity, securities in unrealized loss positions (security) Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Held-to-maturity securities portfolio, number of securities (security) Held-to-maturity, Securities Portfolio Number of Securities Held-to-maturity, Securities Portfolio Number of Securities 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 Accretion Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion Net reclassifications from (to) 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 Payments received, net Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Payments Received Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Payments Received Disposals Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Disposals of Loans Balance at end of period 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] Service charges on deposit accounts Service Charges [Member] Service Charges [Member] Insurance revenue Wealth management fees Interchange income Interchange Income [Member] Interchange Income [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items]