Segment Reporting [Abstract] Statement of Operations and Total Assets by Reportable Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Disaggregation of Revenue [Abstract] Statement [Table] Statement [Table] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Transferred at Point in Time [Member] Transferred at Point in Time [Member] Transferred over Time [Member] Transferred over Time [Member] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Revenue from Contracts with Customers [Member] Revenue from Contract with Customer [Member] Statement [Line Items] Statement [Line Items] Card interchange fees Card interchange fees Fees earned from debit card transactions. Wealth management revenues Investment Banking, Advisory, Brokerage, and Underwriting Fees and Commissions Service charges on deposit accounts Service charges on deposits The amount of fee revenue associated with service charges on deposits recognized in accordance with Topic 606, Revenue from Contracts with Customers. Other income Noninterest Income, Other Total revenues Revenues Statement of Financial Position [Abstract] Held to maturity debt securities, fair value Debt Securities, Held-to-maturity, Fair Value Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Defined Benefit Plan [Abstract] Components of Net Periodic Benefit Cost Schedule of Defined Benefit Plans Disclosures [Table Text Block] Schedule of Assumptions Used for Net Periodic Benefit Cost Schedule of Assumptions Used [Table Text Block] Receivables [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Domain] Class of Financing Receivable, Type [Domain] Commercial Real Estate Commercial Real Estate Portfolio Segment [Member] Commercial & Industrial Commercial Other [Member] Class of financing receivables related to commercial and industrial financing receivables Total Commercial Commercial Portfolio Segment [Member] Residential Real Estate Residential Portfolio Segment [Member] Home Equity Home equity [Domain] Portfolio segment of the company's total financing receivables related to home equity lines and loans. Other Other consumer [Domain] Portfolio segment of the company's total financing receivables related to other consumer loans that are not home equity lines or loans. Total Consumer Consumer Portfolio Segment [Member] 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 Leases [Abstract] Operating lease minimum payments, Due Current Year Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year Operating lease minimum payments, Due Year Two Lessee, Operating Lease, Liability, Payments, Due Year Two Operating lease minimum payments, Due Year Three Lessee, Operating Lease, Liability, Payments, Due Year Three Operating lease minimum payments, Due Year Four Lessee, Operating Lease, Liability, Payments, Due Year Four Operating lease minimum payments, Due Year Five Lessee, Operating Lease, Liability, Payments, Due Year Five Operating lease minimum payments, Due after Year Five Lessee, Operating Lease, Liability, Payments, Due after Year Five Total operating lease payments Lessee, Operating Lease, Liability, Payments, Due Interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value of operating lease liabilities Operating Lease, Liability Net interest income Interest Income (Expense), Net Asset-based wealth management revenues Asset-based wealth management revenues Asset-based revenues include trust and investment management fees that are earned based upon a percentage of asset values under administration Transaction-based wealth management revenues Transaction-based wealth management revenues Transaction-based revenues include financial planning fees, tax preparation fees, commissions and other service fees. Total wealth management revenues Mortgage banking revenues Fees and Commissions, Mortgage Banking and Servicing Loan related derivative income Gain (Loss) on Derivative Instruments, Net, Pretax Income from bank-owned life insurance Bank Owned Life Insurance Income Net realized losses on securities Debt and Equity Securities, Gain (Loss) Total noninterest income Noninterest Income Total revenues Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Table] Commitments and Contingencies Disclosure [Table] Commitments and Contingencies Disclosure [Table] Commitments to Extend Credit [Axis] Commitments to Extend Credit [Axis] This represents commitments to extend credit. Commitments to Extend Credit [Domain] Commitments to Extend Credit [Domain] This represents commitments to extend credit. Commitments to extend credit on standby letters of credit [Member] Commitments to Extend Credit on Standby Letters of Credit [Member] This represents commitments to extend credit on standby letters of credit. Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Commitments to extend credit [Member] Commitments to Extend Credit [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Commitments and Contingencies Disclosure [Line Items] Commitments and Contingencies Disclosure [Line Items] [Line Items] for Commitments and Contingencies Disclosure [Table] Contract amount Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Asset Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Other Consumer [Member] Other Consumer [Member] Fixed-rate consumer installment loans. Nonaccrual Loans, Current Payment Status [Axis] Nonaccrual Loans, Current Payment Status [Axis] Loans on nonaccrual status which are current as to payment of principal and interest. Current Payment Status [Domain] Nonaccrual Loans, Current Payment Status [Domain] Nonaccrual loans which are current as to payment of principal and interest [Domain] Current Payment Status [Member] Current Payment Status [Member] Current Payment Status [Member] Financing Receivable, Recorded Investment, Past Due [Line Items] Financing Receivable, Recorded Investment, Past Due [Line Items] Nonaccrual loans Financing Receivable, Recorded Investment, Nonaccrual Status Accruing loans 90 days or more past due Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing Nonaccrual loans current on payment Loans Receivable, Nonaccrual of Interest, Current Reflects carrying amount of loans on which no interest is being recognized, but are current as to the payment of principal and interest. Income Statement [Abstract] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Interest income: Interest and Dividend Income, Operating [Abstract] Interest and fees on loans Interest and Fee Income, Loans and Leases Interest and Fee Income, Loans Held-for-sale, Mortgages Interest and Fee Income, Loans Held-for-sale, Mortgages Taxable interest on securities Interest Income, Securities, Operating, Taxable Nontaxable interest on securities Interest Income, Securities, Operating, Tax Exempt Dividends on Federal Home Loan Bank stock Dividends on corporate stock and Federal Home Loan Bank stock Dividend income on corporate stock and Federal Home Loan Bank stock. Other interest income Other Interest and Dividend Income Total interest and dividend income Interest and Dividend Income, Operating Interest expense: Interest Expense [Abstract] Deposits Interest Expense, Deposits Federal Home Loan Bank advances Interest Expense Federal Home Loan Bank advances Interest expense incurred during the reporting period on short-term and long-term borrowings associated with Federal Home Loan Bank and Federal Reserve Bank advances. Junior subordinated debentures Interest Expense, Junior Subordinated Debentures Total interest expense Interest Expense Net interest income Provision for loan losses Provision for Loan and Lease Losses Net interest income after provision for loan losses Interest Income (Expense), after Provision for Loan Loss Noninterest income: Noninterest Income [Abstract] Noninterest expense: Noninterest Expense [Abstract] Salaries and employee benefits Labor and Related Expense Outsourced services Outsourced services The total amount of third party vendor costs, which includes platform and product support costs. Net occupancy Occupancy, Net Equipment Equipment Expense Legal, audit and professional fees Professional Fees FDIC deposit insurance costs Federal Deposit Insurance Corporation Premium Expense Advertising and promotion Marketing and Advertising Expense Amortization of intangibles Amortization of Intangible Assets Other expenses Other Noninterest Expense Total noninterest 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 Net Income (Loss) Attributable to Parent Net income applicable to common shareholders Net Income (Loss) Available to Common Stockholders, Diluted Weighted average common shares outstanding - basic Weighted Average Number of Shares Outstanding, Basic Weighted average common shares outstanding - diluted Weighted Average Number of Shares Outstanding, Diluted Per share information: Earnings Per Share [Abstract] Basic earnings per common share Earnings Per Share, Basic Diluted earnings per common share Earnings Per Share, Diluted Cash dividends declared per share Common Stock, Dividends, Per Share, Declared New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Recently Issued Accounting Pronouncements Description of New Accounting Pronouncements Not yet Adopted [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Consolidation Consolidation, Policy [Policy Text Block] Basis of Accounting Basis of Accounting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Earnings Per Common Share Earnings Per Share [Text Block] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Payment Default [Member] Payment Default [Member] Payment Default [Member] Financing Receivable, Modifications [Line Items] Financing Receivable, Modifications [Line Items] Number of loans modified as a troubled debt restructuring Financing Receivable, Modifications, Number of Contracts Financing Receivable, Modifications, Subsequent Default, Recorded Investment Financing Receivable, Modifications, Subsequent Default, Recorded Investment Investments, Debt and Equity Securities [Abstract] Schedule of Available for Sale and Held to Maturity Securities [Table] Schedule of Available for Sale and Held to Maturity Securities [Table] Summary of information required and determined to be disclosed concerning available for sale and held to maturity securities which consist of all investments in certain debt and equity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. Obligations of U.S. government-sponsored enterprises [Member] US Government-sponsored Enterprises Debt Securities [Member] Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member] Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Obligations of states and political subdivisions [Member] US States and Political Subdivisions Debt Securities [Member] Individual name issuer trust preferred debt securities Trust Preferred Securities Individual Name Issuers [Member] This category includes trust preferred securities individual name issuers. Corporate bonds [Member] Corporate Bond Securities [Member] Schedule of Available for Sale and Held to Maturty Securities [Line Items] Schedule of Available for Sale and Held to Maturty Securities [Line Items] Line items for schedule of Available for Sale and Held to Maturty Securities. Available for sale debt securities amortized cost basis Available-for-sale Securities, Amortized Cost Basis Available for sale debt securities unrealized gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Available for sale debt securities unrealized losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Available for sale debt securities, at fair value Available-for-sale Securities Held to maturity debt securities Debt Securities, Held-to-maturity Held to maturity debt securities unrealized gains Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Held to maturity debt securities unrealized losses Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss Total securities amortized cost Available for Sale and Held to Maturity Securities Amortized Cost This represents the total available for sale and held to maturity securities amortized cost. Total securities unrealized gains Available for Sale and Held to Maturity Securities Accumulated Unrecognized Holding Gain This represents the total available for sale and held to maturity securities unrealized gains. Total securities unrealized losses Available for Sale and Held to Maturity Securities Accumulated Unrecognized Holding Loss This represents the total available for sale and held to maturity securities unrealized losses. Total securities fair value Available for Sale and Held to Maturity Securities Fair Value This represents the total available for sale and held to maturity securities fair value. New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Statement, Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Retained Earnings [Member] Retained Earnings [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Operating lease liabilities Rent-related liabilities Rent-related liabilities The amount of the reduction of rent-liabilities upon the adoption date, as a result of adopting ASU 2016-02. Cumulative effect on retained earnings, tax Cumulative Effect on Retained Earnings, Tax Cumulative effect on retained earnings, net of tax Cumulative Effect of New Accounting Principle in Period of Adoption Held to maturity debt securities, at amortized cost Unrealized losses on held to maturity securities, net of tax Accumulated Other Comprehensive Income (Loss), Net of Tax Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Self-originated Mortgages Self-originated Mortgages [Member] Self-originated Mortgages [Member] Purchased Mortgages Purchased Mortgages [Member] Purchased Mortgages [Member] Financing Receivable, Recorded Investment [Line Items] Financing Receivable, Recorded Investment [Line Items] Current Financing Receivable, Recorded Investment, Current Total past due Financing Receivable, Recorded Investment, Past Due Loans Receivable Financing Receivable, Net Statement of Stockholders' Equity [Abstract] Common Stock [Member] Common Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] Common Stock, Shares Outstanding, Beginning Balance Shareholders' Equity, Beginning Balance Stockholders' Equity Attributable to Parent Net income Total other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Cash dividends declared Dividends, Common Stock, Cash Share-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Exercise of stock options and issuance of other compensation-related equity awards, shares ExerciseOfStockOptionsAndIssuanceOfOtherCompensationRelatedEquityInstrumentsShares Shares of stock issued during the period as a result of the exercise of stock options and stock related to other compensation related equity instruments, net of the stock value of such awards forfeited. Exercise of stock options and issuance of other compensation-related equity awards, value Exercise of Stock Options and Issuance of Other Compensation Related Equity Instruments, Value Value of stock issued during the period as a result of the exercise of stock options and value of stock related to restricted stock awards issued during the period, net of the stock value of such awards forfeited. Cumulative effect of change in accounting principle Common Stock, Shares Outstanding, Ending Balance Shareholders' Equity, Ending Balance Fair Value Disclosures [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Level 3 [Member] Fair Value, Inputs, Level 3 [Member] 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] Available for sale debt securities, at fair value Mortgage loans held for sale, measured at fair value Loans Held-for-sale, Fair Value Disclosure Derivative assets Derivative Asset Total assets at fair value on a recurring basis Assets, Fair Value Disclosure Derivative liabilities Derivative Liability Total liabilities at fair value on a recurring basis Financial and Nonfinancial Liabilities, Fair Value Disclosure Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Debt Disclosure [Abstract] Schedule of Federal Home Loan Bank Advances, by Branch of FHLBB Bank [Table] Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] Federal Home Loan Bank Branch [Axis] Federal Home Loan Bank Branch [Axis] Federal Home Loan Bank Branch [Domain] Federal Home Loan Bank Branch [Domain] Federal Home Loan Bank of Boston [Member] Federal Home Loan Bank of Boston [Member] Federal Home Loan Bank, Advances, Branch of FHLBB Bank [Line Items] Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] Scheduled maturity through the end of the current year Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Twelve Months Weighted average rate for scheduled maturity through the end of the current year Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due within One Year of Balance Sheet Date Scheduled maturity in year two Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Two Weighted average rate for scheduled maturity in year two Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, One to Two Years from Balance Sheet Date Scheduled maturity in year three Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Three Weighted average rate for scheduled maturity in year three Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Two to Three Years from Balance Sheet Date Scheduled maturity in year four Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Four Weighted average rate for scheduled maturity in year four Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Three to Four Years from Balance Sheet Date Scheduled maturity in year five Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Five Weighted average rate for scheduled maturity in year five Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Four to Five Years from Balance Sheet Date Scheduled maturity after year five Federal Home Loan Bank, Advances, Maturities Summary, Due after Year Five Weighted average rate for scheduled maturity after year five Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, after Five Years from Balance Sheet Date Federal Home Loan Bank advances Advances from Federal Home Loan Banks Total weighted average rate Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Total Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Total Operating lease cost Operating Lease, Cost Variable lease cost Variable Lease, Cost Total lease cost Lease, Cost Cash paid reducing operating lease liabilities Operating Lease, Payments Statement of Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Net of Tax [Abstract] Other Comprehensive Income (Loss), Net of Tax [Abstract] Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract] Net change in fair value of available for sale debt securities Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax Net change in fair value of cash flow hedges Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Net change in defined benefit plan obligations Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Total other comprehensive income (loss), net of tax Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent 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 [Member] Portion at Fair Value Measurement [Member] Reported Value Measurement [Member] Reported Value Measurement [Member] Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Held to maturity debt securities Loans, net of allowance of loan losses Loans and Leases Receivable, Net Amount Time deposits Time Deposits Federal Home Loan Bank advances Junior subordinated debentures Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust Cash and Cash Equivalents [Abstract] Average reserve deposited with the Board of Governors of the Federal Reserve Bank Cash Reserve Deposited At Federal Reserve Bank Average reserve balance reqired to be maintained at the Federal Reserve Bank. Interest-bearing deposits in other banks Interest-bearing Deposits in Banks and Other Financial Institutions Summary of Loans Schedule of Loans Receivable [Table Text Block] Tabular disclosure of loans receivable along with percent of total loans. Past Due Loans Past Due Financing Receivables [Table Text Block] Impaired Loans Impaired Financing Receivables [Table Text Block] Nonaccrual Loans Schedule of Financing Receivables, Non Accrual Status [Table Text Block] Credit Quality Indicators Commercial Financing Receivable Credit Quality Indicators [Table Text Block] Credit Quality Indicators Residential & Consumer Loan Receivable, Credit Quality Indicators, Residential & Consumer [Table Text Block] Tabular disclosure of financing receivables by credit quality indicator for residential and consumer loans. The credit quality indicator is a statistic about the credit quality of financing receivables. Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Interest rate swaps with customers [Member] Interest Rate Swap with customers [Member] Interest Rate Swap with customers [Member] Mirror swaps with counterparties [Member] Interest Rate Mirror Swaps with Counterparties [Member] This category includes interest rate mirror swaps with counterparties. Risk participation agreements [Member] Risk participation agreements [Member] Risk participation agreements Foreign exchange contracts [Member] Foreign Exchange Contract [Member] Interest rate lock commitments [Member] Interest Rate Lock Commitments [Member] Forward sale commitments [Member] Forward Contracts [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Loan related derivative income [Member] Net Gains Losses on Interest Rate Swaps [Member] This amount represents net gains (losses) on interest rate swaps. Mortgage banking revenues [Member] Net Gains on Loan Sales and Commissions on Loans Originated for Others [Member] This amount is included in net gains on loan sales and commissions on loans originated for others. Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Gain (Loss) Recognized in Income Derivative, Gain (Loss) on Derivative, Net Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Commercial Banking [Member] Commercial Banking [Member] The represents the commercial banking reporting segment. Wealth Management Services [Member] Wealth Management Services [Member] This represents the wealth management services reporting segment. Corporate [Member] Corporate Segment [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Net interest income (expense) Noninterest income Depreciation and amortization expense Depreciation, Depletion and Amortization Other noninterest expenses related to segments Other Noninterest Expenses Related to Segments Other noninterest expenses related to segments. Total assets Assets Expenditures for long-lived assets Payments to Acquire Property, Plant, and Equipment Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Line Items] Loans individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Loans related allowance individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Loans collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Loans related allowance collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Allowance Financing Receivable, Allowance for Credit Losses Leases Lessee, Leases [Policy Text Block] Regulatory Capital Requirements [Abstract] Regulatory Capital Requirements Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Nonrecurring [Member] Fair Value, Measurements, Nonrecurring [Member] Weighted Average [Member] Weighted Average [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Collateral Dependent Impaired Loans [Member] Collateral Dependent Impaired Loans [Member] The represents collateral dependent impaired loans. Property Acquired Through Foreclosure Or Repossession [Member] Property Acquired Through Foreclosure Or Repossession [Member] This represents property acquired through foreclosure or repossession. Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Appraisals Of Collateral [Member] Appraisals Of Collateral [Member] This represent appraisals of collateral valuation techinque used in fair value disclosures. Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31) Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Collateral dependent impaired loans Impaired Financing Receivable, with Related Allowance, Recorded Investment Property acquired through foreclosure or repossession Other Real Estate, Foreclosed Assets, and Repossessed Assets Discount for costs to sell Discount For Costs To Sell This represents the discount applied to appraisals of collateral for costs to sell. Appraisal adjustments Appraisal Adjustments This represents the adjustments to appraisal values to reflect market value declines or other discounts. Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Troubled debt restructuring, pre-modification recorded investment Financing Receivable, Modifications, Pre-Modification Recorded Investment Troubled debt restructuring, post-modification recorded investment Financing Receivable, Modifications, Post-Modification Recorded Investment Regulatory Capital Requirements Regulatory Capital Requirements under Banking Regulations [Text Block] Revenue from Contract with Customer [Abstract] Revenue from Contracts with Customers Revenue from Contract with Customer [Text Block] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Pass [Member] Pass [Member] Special Mention [Member] Special Mention [Member] Classified [Member] Classified [Member] A category of financing receivable which includes loans identified as "substandard", "doubtful" or "loss" based on criteria consistent with guidelines provided by banking regulators. Statement of Cash Flows [Abstract] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Adjustments for Change in Accounting Principle [Domain] Adjustments for Change in Accounting Principle [Domain] Scenario [Axis] Scenario, Unspecified [Domain] 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 Depreciation of premises and equipment Depreciation, Nonproduction Net amortization of premium and discount Amortization of Debt Discount (Premium) Amortization of intangibles Share-based compensation Share-based Compensation Tax benefit from stock option exercises and other equity awards Tax Benefit from Stock Option Exercises and Issuance of Other Compensation-related Equity Instruments Reductions in the entity's income taxes that arise when compensation cost (from stock option and other equity instruments compensation) recognized on the entity's tax return exceeds compensation cost from share-based compensation recognized in financial statements. This element represents the cash inflow reported in the enterprise's financing activities. Income from bank-owned life insurance Net gains on loan sales and commissions on loans originated for others, including fair value adjustments Gain (Loss) on Sales of Loans, Net Proceeds from sales of loans Proceeds from Sale of Loans Held-for-sale Loans originated for sale Payments for Origination of Mortgage Loans Held-for-sale (Increase) decrease in operating lease right-of-use assets (Increase) decrease in operating lease right-of-use assets (Increase) decrease in operating lease right-of-use assets Increase (decrease) in operating lease liabilities Increase (Decrease) in operating lease liabilities Increase (Decrease) in operating lease liabilities (Increase) decrease in other assets Increase (Decrease) in Other Operating Assets Increase (decrease) in other liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by (used in) operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of mortgage-backed securities available for sale Payments to Acquire Mortgage-backed Securities (MBS), Available-for-sale Purchases of other investment securities available for sale Payments to Acquire Available-for-sale Securities Proceeds from sale of other investment securities available for sale Proceeds from Sale of Mortgage-backed Securities (MBS), Available-for-sale Maturities and principal payments of mortgage-backed securities available for sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Maturities and principal payments of other investment securities available for sale Proceeds from Maturities, Prepayments and Calls of Other Investments Maturities and principal payments of mortgage-backed securities held to maturity Proceeds from Maturities, Prepayments and Calls of Mortgage Backed Securities (MBS) Remittance (purchases) of Federal Home Loan Bank stock Payments for (Proceeds from) Federal Home Loan Bank Stock Net (increase) decrease in loans Payments for (Proceeds from) Loans and Leases Purchases of loans Payments to Acquire Loans Held-for-investment Purchases of premises and equipment Purchases of bank-owned life insurance Payment to Acquire Life Insurance Policy, Investing Activities Proceeds from surrender of bank-owned life insurance Proceeds from Life Insurance Policy Net cash provided by (used in) 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 (decrease) in deposits Increase (Decrease) in Deposits Proceeds from Federal Home Loan Bank advances Proceeds from FHLBank Borrowings, Financing Activities Repayment of Federal Home Loan Bank advances Payments of FHLBank Borrowings, Financing Activities Payment of contingent consideration liability Payment for Contingent Consideration Liability, Financing Activities Net proceeds from stock option exercises and issuance of other equity awards Proceeds from Issuance or Sale of Equity Cash dividends paid Payments of Dividends Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) 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 Cash and cash equivalents at end of period Noncash Investing and Financing Activities: Noncash Investing and Financing Items [Abstract] Loans charged off Financing Receivable, Allowance for Credit Losses, Write-downs Loans transferred to property acquired through foreclosure or repossession Transfer of Loans Net to Foreclosed Properties and Repossessions Transfer of Loans Net to Foreclosed Properties and Repossessions Operating lease right-of-use assets Operating lease right-of-use assets The adoption date value of operating lease right-of-use assets recognized upon the adoption of ASU 2016-02, effective 1/1/19. Operating lease liabilities Operating lease liabilities The adoption date value of operating lease liabilities recognized upon the adoption of ASU 2016-02, effective 1/1/19. Fair value of debt securities transferred from held-to-maturity to available for sale Fair value of held-to-maturity securities transferred to available for sale Fair value of debt securities transferred from held-to-maturity to available for sale upon the adoption of ASU 2017-12, effective 1/1/2019. Supplemental Disclosures: Supplemental Cash Flow Information [Abstract] Interest payments Interest Paid, Including Capitalized Interest, Operating and Investing Activities Income tax payments Income Taxes Paid Equity [Abstract] Net Unrealized Gains (Losses) on AFS Securities [Member] Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Net Unrealized Losses on Cash Flow Hedges [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Pension Benefit Adjustment [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Comprehensive Income [Line Items] Accumulated other comprehensive income (loss), beginning balance Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassed from accumulated other comprehensive income (loss) Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Accumulated other comprehensive income (loss), ending balance Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [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 Financing Receivables, 30 to 59 Days Past Due [Member] 60-89 Financing Receivables, 60 to 89 Days Past Due [Member] Over 90 Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Total loans Future minimum lease payments, Next Twelve Months Operating Leases, Future Minimum Payments Due, Next Twelve Months Future minimum lease payments, Two Years Operating Leases, Future Minimum Payments, Due in Two Years Future minimum lease payments, Three Years Operating Leases, Future Minimum Payments, Due in Three Years Future minimum lease payments, Four Years Operating Leases, Future Minimum Payments, Due in Four Years Future minimum lease payments, Five Years Operating Leases, Future Minimum Payments, Due in Five Years Future minimum lease payments, Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total minimum lease payments Operating Leases, Future Minimum Payments Due Defined Benefit Pension Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Calculation of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivatives Designated as Cash Flow Hedging Instruments [Member] Designated as Hedging Instrument [Member] Interest rate caps [Member] Interest Rate Cap [Member] Interest rate swaps [Member] Interest Rate Swap [Member] Interest rate floors [Member] Interest Rate Floor [Member] Derivative Financial Instruments, Assets [Member] Derivative Financial Instruments, Assets [Member] Derivative Financial Instruments, Liabilities [Member] Derivative Financial Instruments, Liabilities [Member] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other assets [Member] Other Assets [Member] Other liabilities [Member] Other Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative assets designated as a cash flow hedge Interest Rate Cash Flow Hedge Asset at Fair Value Derivative liabilities designated as a cash flow hedge Interest Rate Cash Flow Hedge Liability at Fair Value Derivative assets not designated Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value Derivative liabilities not designated Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value Gross derivative positions Derivative Asset, Fair Value, Gross Asset Gross derivative positions Derivative Liability, Fair Value, Gross Liability Amounts offset in balance sheet Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset Amounts offset in balance sheet Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset Net amounts presented in balance sheet Derivative Asset, Fair Value, Amount Offset Against Collateral Net amounts presented in balance sheet Derivative Liability, Fair Value, Amount Offset Against Collateral Collateral pledged Derivative, Collateral, Obligation to Return Cash Collateral pledged Derivative, Collateral, Right to Reclaim Cash Net amounts Derivative, Fair Value, Amount Offset Against Collateral, Net Fair Value of Derivatives by Balance Sheet Location Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Derivative Instruments Effect in Statements of Income and Changes in Shareholders' Equity Derivative Instruments, Gain (Loss) [Table Text Block] Maximum [Member] Fair value of available for sale and held to maturity securities pledged as collateral Security Owned and Pledged as Collateral, Fair Value Amortized cost of callable debt securities Callable Debt Securities Amortized Cost This represents the amortized cost for callable debt securities. Fair value of callable debt securities Callable Debt Securities Fair Value This represents the fair value for callable debt securities. Maturity period of callable debt securities Callable Debt Securities, Maturity Period Callable Debt Securities, Maturity Period Call features of callable debt securities Callable Debt Securities, Call Feature, Period Callable Debt Securities, Call Feature, Period Number of securities in a continuous unrealized loss position total Available-for-sale Securities, Continuous Unrealized Loss Position, Total, Number This item represents the number of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position. Securities in unrealized loss position, number of companies issuing securities Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Companies Issuing Securities Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Companies Issuing Securities Amortized cost of trust preferred securities of individual name issuers that are below investment grade Trust Preferred Securities Individual Name Issuer Amortized Cost Below Investment Grade This represents the amortized cost for trust preferred securities for individual name issuers that are below investment grade. Unrealized losses of trust preferred securities of individual name issuers that are below investment grade Trust Preferred Securities Individual Name Issuer Unrealized Losses Below Investment Grade This represents the unrealized losses for trust preferred securities for individual name issuers that are below investment grade. Unrealized losses of securities in a continuous unrealized loss position total Available for Sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Accumulated Investments Available for Sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Accumulated Investments Schedule of remaining operating lease payments, inclusive of renewal options Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of total lease expense Lease, Cost [Table Text Block] Schedule of future minimum lease payments Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Borrowings Debt Disclosure [Text Block] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Recorded Investment of Impaired Loans with No Related Allowance Impaired Financing Receivable, with No Related Allowance, Recorded Investment Recorded Investment of Impaired Loans with Related Allowance Total Recorded Investment of Impaired Loans Impaired Financing Receivable, Recorded Investment Unpaid Principal of Impaired Loans with No Related Allowance Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Unpaid Principal of Impaired Loans with Related Allowance Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Total Unpaid Principal of Impaired Loans Impaired Financing Receivable, Unpaid Principal Balance No Related Allowance on Impaired Loans Impaired Financing Receivable, No Related Allowance Amount of allowance for credit losses related to recorded investment. Related Allowance on Impaired Loans Impaired Financing Receivable, Related Allowance Retirement Benefits [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Qualified Pension Plan [Member] Pension Plan [Member] Non-Qualified Retirement Plans [Member] Supplemental Employee Retirement Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Equivalent single discount rate for benefit obligations Equivalent single discount rate for benefit obligations The interest rate used to adjust for the time value of money in the calculation of the defined benefit obligation. Equivalent single discount rate for service cost The interest rate used to adjust for the time value of money in the calculation of the service cost component of net periodic benefit cost. Equivalent single discount rate for interest cost Equivalent single discount rate for interest cost The interest rate used to adjust for the time value of money in the calculation of the interest cost component of net periodic benefit cost. Expected long-term return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Rate of compensation increase Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Receivables from contracts with customers Contract with Customer, Asset, Net Contract cost assets Capitalized Contract Cost, Net 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] Corporation [Member] Parent Company [Member] Bank [Member] Subsidiaries [Member] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Total Capital (to Risk-Weighted Assets): Capital [Abstract] Total Capital Capital Total Capital to Risk-Weighted Assets Capital to Risk Weighted Assets Total Capital for Capital Adequacy Purposes Capital Required for Capital Adequacy Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets Capital Required for Capital Adequacy to Risk Weighted Assets Total Capital To Be Well Capitalized Capital Required to be Well Capitalized Total Capital To Be Well Capitalized to Risk Weighted-Assets Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Capital (to Risk-Weighted Assets): Tier One Risk Based Capital [Abstract] Tier 1 Capital Tier One Risk Based Capital Tier 1 Capital to Risk Weighted-Assets Tier One Risk Based Capital to Risk Weighted Assets Tier 1 Capital Required For Capital Adequacy Purposes Tier One Risk Based Capital Required for Capital Adequacy Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier 1 Capital Required To Be Well Capitalized Tier One Risk Based Capital Required to be Well Capitalized Tier 1 Capital Required To Be Well Capitalized to Risk Weighted-Assets Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Common Equity Tier 1 Capital [Abstract] Common Equity Tier 1 Capital [Abstract] Common Equity Tier 1 Capital [Abstract] Common Equity Tier 1 Capital Common Equity Tier 1 Capital Common Equity Tier 1 Capital Common Equity Tier 1 Capital to Risk Weighted Assets Common Equity Tier 1 Capital to Risk Weighted Assets Common Equity Tier 1 Capital to Risk Weighted Assets Common Equity Tier 1 Capital Required for Capital Adequacy Common Equity Tier 1 Required for Capital Adequacy Common Equity Tier 1 Required for Capital Adequacy Common Equity Tier 1 Capital for Capital Adequacy to Risk Weighted Assets Common Equity Tier 1 Capital for Capital Adequacy to Risk Weighted Assets Common Equity Tier 1 Capital for Capital Adequacy to Risk Weighted Assets Common Equity Tier 1 Capital Required to be Well Capitalized Common Equity Tier 1 Capital Required to be Well Capitalized Common Equity Tier 1 Capital Required to be Well Capitalized Common Equity Tier 1 Capital Required to be Well Capitalized to Risk Weighted Assets Common Equity Tier 1 Capital Required to be Well Capitalized to Risk Weighted Assets Common Equity Tier 1 Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Capital (to Average Assets): Tier One Leverage Capital [Abstract] Tier 1 Leverage Capital Tier One Leverage Capital Tier 1 Leverage Capital to Average Assets Tier One Leverage Capital to Average Assets Tier 1 Leverage Capital Required for Capital Adequacy Purposes Tier One Leverage Capital Required for Capital Adequacy Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets Tier One Leverage Capital Required for Capital Adequacy to Average Assets Tier 1 Leverage Capital Required To Be Well Capitalized Tier One Leverage Capital Required to be Well Capitalized Tier 1 Leverage Capital Required To Be Well Capitalized to Average Assets Tier One Leverage Capital Required to be Well Capitalized to Average Assets 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] Performance Based Nonvested Shares [Member] Performance Based Nonvested Shares [Member] Performance based nonvested shares. Time Based Nonvested Shares [Member] Time Based Nonvested Shares [Member] Time based nonvested shares. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Performance share awards, grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in the Period, Grant Date Fair Value The fair value at date of grant for nonvested performance equity based awards during the period. Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Performance share awards, shares vesting Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Shares Vesting Shares vesting for performance nonvested equity based awards based on the most recent information available. Nonvested share units granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Nonvested share units weighted average grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Cash and Due from Banks Cash and Cash Equivalents Disclosure [Text Block] Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Changes in fair value of available for sale debt securities, before tax Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, before Tax Changes in fair value of available for sale debt securities, tax Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Changes in fair value of available for sale debt securities Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Net gains (losses) on debt securities reclassified into earnings, before tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Net gains (losses) on debt securities reclassified into earnings, tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Net gains (losses) on debt securities reclassified into earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Net change in fair value of available for sale debt securities, before tax Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax Net change in fair value of available for sale debt securities, tax Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax Net change in fair value of available for sale debt securities Change in fair value of cash flow hedges, before tax Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Change in fair value of cash flow hedges, tax Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Change in fair value of cash flow hedges Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Net cash flow hedge losses reclassified into earnings, before tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Net cash flow hedge losses reclassified into earnings, tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Net cash flow hedge losses reclassified into earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Net change in fair value of cash flow hedges, before tax Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax Net change in fair value of cash flow hedges, tax Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Net change in fair value of cash flow hedges Amortization of net actuarial losses, before tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Amortization of net actuarial losses, tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax Amortization of net actuarial losses Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Amortization of net prior service credits, before tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax Amortization of net prior service credits, tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax Amortization of net prior service credits Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax Net change in defined benefit plan obligations, before tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Net change in defined benefit plan obligations, tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Net change in defined benefit plan obligations Total other comprehensive income (loss), before tax Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Total other comprehensive income (loss), tax Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Business Segments Segment Reporting Disclosure [Text Block] Share-Based Compensation Arrangements Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Cover page. Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Document Transition Report Document Transition Report Document Quarterly Report Document Quarterly Report Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Entity File Number Entity File Number City Area Code City Area Code Local Phone Number Local Phone Number Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Shell Company Entity Shell Company Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Title of 12(g) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Tax Identification Number Entity Tax Identification Number Entity Address, Postal Zip Code Entity Address, Postal Zip Code Available for sale debt securities maturities within 1 year amortized cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Available for sale debt securities maturities 1-5 years amortized cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Available for sale debt securities maturities 5-10 years amortized cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Available for sale debt securities maturities after 10 years amortized cost Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost Available for sale debt securities maturities total amortized cost Debt Securities, Available-for-sale, Amortized Cost Available for sale debt securities maturities within 1 year fair value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Available for sale debt securities maturities 1-5 years fair value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Available for sale debt securities maturities 5-10 years fair value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Available for sale debt securities maturities after 10 years fair value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Available for sale debt securities fair value Debt Securities, Available-for-sale Mortgage Loans Held for Sale [Member] Mortgage Loans Held for Sale [Member] Mortgage Loans Held for Sale [Member] Mortgage loans held for sale, amortized cost Loans Receivable Held-for-sale, Amount Mortgage loans held for sale, difference between fair value and amortized cost Mortgage Loans Held for Sale Difference between Fair Value and Principal Amount The difference between the fair value and principal amount of mortgage loans held for sale. Change in fair value under fair value option election Fair Value, Option, Changes in Fair Value, Gain (Loss) Allowance for Loan Losses Allowance for Credit Losses [Text Block] Schedule of Gain (Loss) on Securities [Table] Schedule of Gain (Loss) on Securities [Table] Gain (Loss) on Securities [Line Items] Gain (Loss) on Securities [Line Items] Proceeds from sales Gross realized gains Available-for-sale Securities, Gross Realized Gains Gross realized losses Available-for-sale Securities, Gross Realized Losses Allowance for Loan Losses Rollforward Analysis Allowance for Credit Losses on Financing Receivables [Table Text Block] Schedule of Allowance for Loan Loss by Segment & Impairment Methodology Schedule of Allowance for Loan Losses by Segent & Impairment Methodology [Table Text Block] Tabular disclosure of loans receivable and associated allowance for loan loss by portfolio segment and disaggregated on the basis of impairment methodology. Total assets at fair value on a nonrecurring basis Leases Leases of Lessee Disclosure [Text Block] Loans Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Forecast [Member] Scenario, Forecast [Member] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service (credit) cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Recognized net actuarial loss Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Assets: Assets [Abstract] Cash and due from banks Cash and Due from Banks Short-term investments Other Short-term Investments Mortgage loans held for sale Trade and Loans Receivables Held-for-sale, Net, Not Part of Disposal Group Securities: Marketable Securities [Abstract] Total securities Marketable Securities Federal Home Loan Bank stock, at cost Federal Home Loan Bank Stock Loans: Loans and Leases Receivable, Net Amount [Abstract] Less allowance for loan losses Loans and Leases Receivable, Allowance Net loans Premises and equipment, net Property, Plant and Equipment, Net Investment in bank-owned life insurance Bank Owned Life Insurance Goodwill Goodwill Identifiable intangible assets, net Intangible Assets, Net (Excluding Goodwill) Other assets Other Assets Total assets Liabilities: Liabilities [Abstract] Noninterest-bearing deposits Noninterest-bearing Domestic Deposit, Demand Interest-bearing deposits Interest-bearing Deposit Liabilities Total deposits Deposits Junior subordinated debentures Other liabilities Other Liabilities Total liabilities Liabilities Commitments and contingencies (Note 18) Commitments and Contingencies Shareholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock Common Stock, Value, Issued Paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Total shareholders' equity Total liabilities and shareholders’ equity Liabilities and Equity Average Recorded Investment of Impaired Loans Impaired Financing Receivable, Average Recorded Investment Interest Income Recognized on Impaired Loans Impaired Financing Receivable, Interest Income, Cash Basis Method Fair value of Mortgage Loans Held for Sale Fair Value Option, Disclosures [Table Text Block] Items Recorded at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Items Recorded at Fair Value on a Nonrecurring Basis Fair Value Measurements, Nonrecurring [Table Text Block] Quantitative Information About Level 3 Assets Measured at Fair Value on a Nonrecurring Basis Fair Value Inputs Assets Nonrecurring Quantitative Information [Table Text Block] Tabular disclosure of quantitative information about the inputs used in the fair value measurement of nonrecurring assets. This disclosure may include, but is not limited to, the fair value of the asset, valuation technique used to measure fair value, the inputs used to measure fair value, the ranges of the inputs, and the weighted averages of the inputs. Carrying Amounts and Estimated Fair Values of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Activity in Other Comprehensive Income (Loss) Comprehensive Income (Loss) [Table Text Block] Components of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Number of securities in a continuous unrealized loss position for less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number This item represents the number of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months. Fair value of securities in a continuous unrealized loss position for less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Unrealized losses of securities in a continuous unrealized loss position for less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss, Accumulated Investments Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss, Accumulated Investments Number of securities in a continuous unrealized loss position for 12 months or longer Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number This item represents the number of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer. Fair value of securities in a continuous unrealized loss position for 12 months or longer Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss, Accumulated Investments Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss, Accumulated Investments Fair value of securities in a continuous unrealized loss position total Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Contingent Consideration by Type [Axis] Contingent Consideration by Type [Axis] Contingent Consideration Type [Domain] Contingent Consideration Type [Domain] Contingent Consideration [Member] Contingent Consideration [Member] Contingent Consideration [Member] Earn-out period post acquisition Earn-out period post acquisition The period of time in which contingent consideration as a result of the acquisition can be earned. Payment of contingent consideration liability Contingent consideration liability Business Combination, Contingent Consideration, Liability Allowance For Loan Loss Allocation on Collateral Dependent Impaired Loans Allowance For Loan Loss Allocation on Collateral Dependent Impaired Loans The allowance for loan loss allocation on collateral dependent impaired loans. Fair Value Measurements Fair Value Disclosures [Text Block] Recorded investment in Troubled Debt Restructuring, Recorded Investment Financing Receivable, Modifications, Recorded Investment Specific Reserves on Troubled Debt Restructurings Specific Reserves on Troubled Debt Restructurings The amount of specific reserves on troubled debt restructurings. Financial Instruments with Off Balance Sheet Risk Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block] Operating lease weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Lease Expiration Period Lease Expiration Period Lease Expiration Period Operating lease renewal term Lessee, Operating Lease, Renewal Term Lease Expiration Period, Renewal Option Lease Expiration Period, Renewal Option Lease Expiration Period, Renewal Option Operating leases, weighted average lease term Operating Lease, Weighted Average Remaining Lease Term Operating lease rent expense Options to extend reasonably certain of being exercised Reasonably certain to renew lease option Amount included in operating lease payment for which the Corproation is reasonably certain to exercise the option to renew a lease. Short-term operating lease liabilities Operating Lease, Liability, Current Federal Home Loan Bank Advances Maturities Schedule of Federal Home Loan Bank, Advances, by Branch of FHLB Bank [Table Text Block] Less dividends and undistributed earnings allocated to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Net income applicable to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Less dividends and undistributed earnings allocated to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted Net income applicable to common shareholders Dilutive effect of common stock equivalents Weighted Average Number Diluted Shares Outstanding Adjustment Weighted average common shares outstanding - diluted Antidilutive common stock equivalents Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Derivative Instruments, Gain (Loss) by Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedge [Member] Cash Flow Hedging [Member] Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Domain] Other Comprehensive Income Location [Domain] Other Comprehensive Income (Loss) [Member] Other Comprehensive Income (Loss) [Member] Summary of Investments Unrealized Gain (Loss) on Investments [Table Text Block] Securities by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] Securities in a Continuous Unrealized Loss Position Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block] Schedule of Realized Gain (Loss) Schedule of Realized Gain (Loss) [Table Text Block] Trust preferred securities included in Tier 1 Capital Debt Instrument, Face Amount Schedule of Fair Value, Off-balance Sheet Risks [Table] Schedule of Fair Value, Off-balance Sheet Risks [Table] Commitments to extend credit on commerical loans [Member] Commitments to Extend Credit on Commerical Loans [Member] This represents commitments to extend credit on commerical loans. Commitments to extend credit on home equity lines [Member] Commitments to Extend Credit on Home Equity Lines [Member] This represents commitments to extend credit on home equity lines. Commitments to extend credit on other loans [Member] Commitments to Extend Credit on Other Loans [Member] This represents commitments to extend credit on other loans. Risk participation-in agreement [Member] Risk participation-in agreement [Member] Risk participation-in agreement [Member] - Represents the agreement the Corporation has with another bank, where the Corporation is participating in a commercial loan arrangement and the participating bank guarantees the performance on a borrower-related interest rate swap contract. Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Notional amount Derivative, Notional Amount Loans Receivable Net Deferred Cost Originated Loans Receivable Net Deferred Cost Originated Reflects cumulative amount of net costs paid by borrowers which have not been taken into expense. Loans Receivable Net Deferred Premium on Purchased Loans Loans Receivable Net Deferred Premium on Purchased Loans Reflects premiums over or discounts from face amounts of acquired loans that are being amortized into income as an adjustment to yield. Loans Pledged as Collateral Loans Pledged as Collateral Past due loans included in nonaccrual loans Loans Receivable, Past Due, Nonaccrual Reflects carrying value of loans which are past due and on nonaccrual status. Mortgage Loans in Process of Foreclosure Mortgage Loans in Process of Foreclosure, Amount Risk participation-out agreement [Member] Risk participation-out agreement [Member] Risk participation agreement [Member] - Represents the agreement the Corporation has with another bank participating in a commercial loan arrangement and the participating bank guarantees the performance on a borrower-related interest rate swap contract. Number of instruments held Derivative, Number of Instruments Held Interest rate cap interest rate Derivative, Cap Interest Rate Interest rate floor interest rate Derivative, Floor Interest Rate Transition Period Pension Plan Amendment Transition Period Pension Plan Amendment The period in which pension plans amendments will transition. Financing Receivable Information by Portfolio Segment [Axis] Financing Receivable Allowance [Domain] Financing Receivable, Allowance for Credit Losses [Roll Forward] Financing Receivable, Allowance for Credit Losses [Roll Forward] Allowance, Beginning Balance Charge-offs Recoveries Financing Receivable, Allowance for Credit Losses, Recovery Provision Provision for Loan, Lease, and Other Losses Allowance, Ending Balance Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] General Information Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Unused line of credit with FHLBB Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds Unused remaining available borrowing capacity with FHLBB Line of Credit Facility, Remaining Borrowing Capacity