Amortized cost of securities transferred Available-for-Sale Securities, Transferred Security, at Carrying Value Available-for-Sale Securities, Transferred Security, at Carrying Value Post-Retirement Benefits Postemployment Benefit Plans, Policy [Policy Text Block] Summary Other Real Estate Owned [Abstract] Summary Other Real Estate Owned [Abstract] -- None. No documentation exists for this element. -- Award Timing Predetermined Award Timing Predetermined [Flag] Impairment reserve Valuation Allowance for Impairment of Recognized Servicing Assets, Balance Federal Home Loan Bank Advances Advance from Federal Home Loan Bank, Fiscal Year Maturity [Abstract] Net unrealized loss on securities transferred from available for sale to held to maturity Unamortized balance of net unrealized losses transferred Other Comprehensive Income (Loss), Accumulated Unrealized Gain (Loss) on Transfer of Available-for-sale Securities to Held-to-maturity Other Comprehensive Income (Loss), Accumulated Unrealized Gain (Loss) on Transfer of Available-for-sale Securities to Held-to-maturity Restricted equity securities, at cost Restricted Equity Securities, at Cost Amount of stock held at Federal Home Loan Bank and Federal Reserve Bank. Federal Home Loan Bank (FHLB) stock and Federal Reserve Bank Stock represents an equity interest in a FHLB of FRB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Interest Rate Swap March 01 2028 Interest Rate Swap March 01 2028 [Member] Interest Rate Swap March 01 2028 Amortization of investments in tax credit structures Investment Program, Proportional Amortization Method, Applied, Amortization Expense Entity File Number Entity File Number Tax credits from investments Investment Program, Proportional Amortization Method, Elected, Income Tax Credit Agency and mortgage-backed securities US Treasury And Government And Collateralized Mortgage-Backed Securities [Member] US Treasury And Government And Collateralized Mortgage-Backed Securities Number of offices Number Of Offices Number Of Offices Tabular List, Table Tabular List [Table Text Block] Related deferred taxes Other Comprehensive Income (Loss), Tax New Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Estimated Fair Value of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Measurement Basis [Axis] Measurement Basis [Axis] Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Construction loans, maximum percent of capital Construction Loan Portfolio Maximum To Company Capital The regulatory maximum allowed ratio of loan portfolio to Company capital for construction loans. Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Securities to be held to maturity Debt Securities, Held-to-Maturity, Maturity [Abstract] Recoveries Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery Disclosure of Repurchase Agreements [Abstract] Disclosure of Repurchase Agreements [Abstract] Income Tax [Line Items] Income Tax [Line Items] Income Tax [Line Items] Number of shares issued during period, employee benefit plan (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Issuance of restricted stock, net of forfeitures (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Interest rate cap agreements Interest Rate Cap [Member] Actual Common Equity Tier One Risk Based Capital Common Equity Tier One Risk Based Capital Retired Executive Officer Loans and Leases Receivables, Related Parties, Retired Executive Officer, Aggregated Over 60,000 Dollars Loans and Leases Receivables, Related Parties, Retired Executive Officer, Aggregated Over 60,000 Dollars Number of private activity bonds Number of Private Activity Bonds Issued by Well-Known Customers Number of Private Activity Bonds Issued by Well-Known Customers Adjustment to Compensation, Amount Adjustment to Compensation Amount Net increase in other assets and accrued interest Decrease (increase) in other assets Increase (Decrease) in Other Operating Assets Principles of Consolidation Consolidation, Policy [Policy Text Block] Equity compensation expense Equity compensation expense Share-Based Payment Arrangement, Noncash Expense Federal income tax expense Federal Income Tax Expense (Benefit), Continuing Operations Employee Stock Option Share-Based Payment Arrangement, Option [Member] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Certificates $250,000 and over Time Deposits 250000 Or More The aggregate amount of domestic or foreign time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to more than $250,000. Income taxes paid Income Taxes Paid Debit card income Debit Card [Member] Schedule of Common Stock Issued Or Repurchased [Table] Schedule of Common Stock Issued Or Repurchased [Table] -- None. No documentation exists for this element. -- Net deferred loan costs Deferred Tax Liabilities, Financing Arrangements Rate Effective Income Tax Rate Reconciliation, Percent [Abstract] (Purchase) redemption of restricted equity securities Redemption (Purchase) of Restricted Equity Securities Redemption of stock held at Federal Home Loan Bank of Federal Reserve Bank. Federal Home Loan Bank (FHLB) stock and Federal Reserve Bank Stock represents an equity interest in a FHLB of FRB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Total shareholders' equity Balance at beginning of year Balance at end of year Shareholders' equity Equity, Attributable to Parent Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Other comprehensive income (loss), net of tax Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax [Abstract] Insider Trading Policies and Procedures [Line Items] Schedule of Premises and Equipment Property, Plant and Equipment [Table Text Block] Number of shares authorized (in shares) Common Stock, Shares Authorized Financial assets Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Proceeds from sale of common stock (in shares) Stock Issued During Period, Shares, New Issues Loss Contingency [Abstract] Loss Contingency [Abstract] Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Liabilities and shareholders' equity Liabilities and Equity [Abstract] To be well-capitalized under prompt corrective action provisions Banking Regulation, Tier 1 Leverage Capital, Well Capitalized, Minimum Unrealized gain on derivative instruments Deferred Tax Liabilities, Derivatives Cover [Abstract] Cover [Abstract] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Maximum Maximum [Member] Amortized Cost Amortized cost Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss Fair Value Debt Securities, Available-for-Sale, Unrealized Loss Position Amortized Cost, Due after 10 years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Restricted Stock Restricted Stock [Member] To be well-capitalized under prompt corrective action provisions Banking Regulation, Tier 1 Risk-Based Capital, Well Capitalized, Minimum Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Net (loss) gain on disposal of premises and equipment Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Other Assets Other Assets [Member] Dividends receivable Dividends Receivable Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Interest on deposits with other banks Interest Income, Deposits with Financial Institutions Financing receivable term extension Financing Receivable, Modified, Weighted Average Term Increase from Modification Combination of Payment Deferral, Term & Rate Mod Extended Maturity, Payment Deferral And Interest Rate Reduction [Member] Extended Maturity, Payment Deferral And Interest Rate Reduction Remitted Equity In Remitted Earnings From Subsidiary This element represents the earnings from a subsidiary that have been paid. An example would be payment in the form of dividends. Moving average of weekly prepayment data (in months) Moving average of weekly prepayment data The moving average period of weekly prepayment data used as assumption in evaluating the carrying value of mortgage servicing rights. Prior Period Adjustment [Abstract] Prior Period Adjustment [Abstract] Income before income taxes Pretax income from continuing operations Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Actual (in hundredths) Banking Regulation, Tier 1 Leverage Capital Ratio, Actual Common stock Common Stock, Number of Shares, Par Value and Other Disclosure [Abstract] Interest rate, due in year two Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Two Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Two Revolving Loans Converted to Term Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Proceeds from sale of premises and equipment Proceeds from Sale of Property, Plant, and Equipment Amortization of mortgage servicing rights Amortization of Mortgage Servicing Rights (MSRs) Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Schedule of Income Taxes Paid Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Remaining lease term Lessee, Operating Lease, Remaining Lease Term Net unrealized loss on hedging derivative instruments Net unrealized loss on cash flow hedging derivative instruments, net of tax Net unrealized gain (loss) on cash flow hedging derivative instruments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Unrealized loss on securities available for sale Deferred Tax Asset, Debt Securities, Available-for-Sale, Unrealized Loss Total interest expense Interest expense Interest Expense, Operating Amortized Cost, Due in 1 year or less Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Schedule of Loans to Directors, Officers and Employees which exceed $60,000 Loans to Directors, Officers and Employees which exceed $60,000 [Table Text Block] Tabular disclosure for loans to directors, officers and employees which exceed specific reporting thresholds. Allowance for Individually Analyzed Loans Financing Receivable, Allowance for Credit Loss, Individually Evaluated Document Fiscal Period Focus Document Fiscal Period Focus Award Timing Method Award Timing Method [Text Block] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss Award Type [Axis] Award Type [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Parent Company Parent Company [Member] Trading Symbol Trading Symbol 2029 Lessee, Operating Lease, Liability, to be Paid, Year Four National certificates of deposit National Certificates of Deposit The aggregate amount of national time deposits, including certificates of deposits, individual retirement accounts and open accounts. Interest and dividends on investments (tax-exempt income) Interest Income, Securities, Operating, Tax Exempt Changes in valuation allowances Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent 2025 Year Awarded 2025 [Member] Year Awarded 2025 Entity Address, City or Town Entity Address, City or Town Loss before Bank earnings Income (loss) before Bank earnings Income (loss) before Bank Earnings Restricted equity securities Federal Home Loan Bank Stock and Federal Reserve Bank Stock Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Range of repurchase agreements' maturity dates (days) Repurchase Agreement Counterparty, Maturity of Agreements Repurchase Agreement Counterparty, Maturity of Agreements Total deferred tax asset Deferred Tax Assets, Net of Valuation Allowance Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Net increase (decrease) in short-term borrowings Proceeds from (Repayments of) Short-Term Debt Yearly amortization expense until fully amortized Amortization of Intangible Assets, Yearly Expense till Fully Amortized Amortization of Intangible Assets, Yearly Expense till Fully Amortized Allowance for Credit Losses Credit Loss, Financial Instrument [Policy Text Block] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Nonaccrual with Allowance for Credit Loss Financing Receivable, Nonaccrual, With Allowance Financing Receivable, Nonaccrual, With Allowance Repayments Loans and Leases Receivables, Related Parties, Collections, Aggregated Over 60,000 Dollars Loans and Leases Receivables, Related Parties, Collections, Aggregated Over 60,000 Dollars Other Other Collateral [Member] Other Collateral Loans used to collateralize borrowings from the Federal Home Loan Bank of Boston Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged Entity Emerging Growth Company Entity Emerging Growth Company Condensed Financial Information of Parent Condensed Financial Information of Parent Company Only Disclosure [Text Block] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Unfunded Loan Commitment Unfunded Loan Commitment [Member] Non-interest income Revenue from Contract with Customer, Including Assessed Tax Restricted stock grants DeferredTaxAssetRestrictedStockGrants DeferredTaxAssetRestrictedStockGrants Expected future benefit payments in 2026 Defined Benefit Plan, Expected Future Benefit Payment, Year One Investment, Proportional Amortization Method, Elected, Statement of Financial Position [Extensible Enumeration] Investment, Proportional Amortization Method, Elected, Statement of Financial Position [Extensible Enumeration] Total non-interest income Non-interest income Noninterest Income Number of shares outstanding (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Outstanding Total income Total income Total parent level income Net gain on sales of loans Gain (Loss) on Sales of Loans, Net Net unrecognized (loss) gain on postretirement benefits Unrecognized loss on postretirement benefit costs Other Comprehensive Income (Loss), Defined Benefit Plan, Transition Asset (Obligation), Reclassification Adjustment from AOCI, after Tax Unrealized Losses Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss Loans Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Non-interest expense Noninterest Expense [Abstract] Cash and cash equivalents Cash and Due from Banks Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Change in benefit obligations Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Fair Value (Estimated), Due in 1 to 5 years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Financing receivable, interest rate reduction (as a percent) Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification Cash paid for amounts included in the measurement of lease liabilities Cash Flow, Lessee [Abstract] Cash Flow, Lessee Pledged Status [Domain] Pledged Status [Domain] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Interest and dividends on investments (includes tax-exempt income of $7,793,000 in 2025, $7,940,000 in 2024, and $8,032,000 in 2023) Interest and Dividend Income, Securities, Operating Applicable tax expense Reported income tax expense Applicable income taxes Income taxes Income Tax Expense (Benefit) Other assets Other assets Other Assets Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Hedging Relationship [Axis] Hedging Relationship [Axis] Fair Value (Estimated), Due in 1 year or less Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Net unrealized loss on securities available for sale AOCI, Debt Securities, Available-for-Sale, Adjustment, after Tax Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Financing receivable, WSJP rate (as a percent) Financing Receivable, Modified, Weighted-Average Interest Rate after Modification Other Income and Expenses [Abstract] Other Income and Expenses [Abstract] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Tier 1 capital to risk-weighted assets Banking Regulation, Tier 1 Risk-Based Capital [Abstract] Other unused commitments Unused lines of Credit [Member] Domestic Federal Income Taxes Paid Income Tax Paid, Federal, after Refund Received All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] 2028 Finance Lease, Liability, to be Paid, Rolling Year Three Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Tax exempt income Effective Income Tax Rate Reconciliation, Tax Exempt Income, Percent Other Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Other operating income Noninterest Income, Other Operating Income Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Securities available for sale Securities available for sale Fair Value (Estimated) Debt Securities, Available-for-Sale, Excluding Accrued Interest Proceeds from sales of other real estate owned Proceeds from Sale of Other Real Estate Net interest income Interest Income (Expense), Operating Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Actual Banking Regulation, Tier 1 Risk-Based Capital, Actual Depreciation Depreciation Due in year four maturity Federal Home Loan Bank, Advance, Maturity, Year Four Income (Numerator) Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Equity Components [Axis] Equity Components [Axis] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Year Four Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year Standby letters of credit Standby Letters of Credit [Member] Financing receivable term extension amortized Financing Receivable, Amortized, Weighted Average Term Increase from Modification Financing Receivable, Amortized, Weighted Average Term Increase from Modification Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Commercial Real Estate Commercial Real Estate [Member] Less accumulated depreciation Property, Plant And Equipment And Operating Lease Right-Of-Use Asset Accumulated Depreciation And Amortization Property, Plant And Equipment And Operating Lease Right-Of-Use Asset Accumulated Depreciation And Amortization Entity Address, State or Province Entity Address, State or Province Substandard (risk rating 7) Substandard [Member] Total interest income Interest income Interest and Dividend Income, Operating Special Mention (risk rating 6) Special Mention [Member] Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Expected future benefit payments in 2029 Defined Benefit Plan, Expected Future Benefit Payment, Year Four Total loans Loans Receivable, Fair Value Disclosure Equity in earnings of Bank Equity in earnings of Bank [Abstract] -- None. No documentation exists for this element. -- Individual: Individual [Axis] Expense related to 401(k) plan Defined Contribution Plan, Cost Document Annual Report Document Annual Report Other operating expense Other Operating Expense [Abstract] Other Operating Expense [Abstract] Real Estate Owned Valuation Allowance [Roll Forward] Real Estate Owned Valuation Allowance [Roll Forward] Principal Forgiveness Principal Forgiveness [Member] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Legal Contingencies Contingencies Disclosure [Text Block] Amortization of investments in tax credit structures Other Depreciation and Amortization For capital adequacy purposes Banking Regulation, Tier 1 Risk-Based Capital, Capital Adequacy, Minimum Entity Interactive Data Current Entity Interactive Data Current Reserves for Qualitative Factors Reserve for Qualitative Factors [Member] Qualitative reserves judgmentally adjusted for local and national economic conditions, concentrations, portfolio composition, and other factors. Condensed Income Statement [Table] Condensed Income Statement [Table] Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Modified [Line Items] Home Equity Line of Credit Home Equity Line of Credit [Member] Unremitted Unremitted earnings of Bank Equity In Unremitted Earnings From Subsidiary This element represents the earnings in a subsidiary that have not been paid to the parent company. Accrued benefit cost Defined Benefit Plan, Funded (Unfunded) Status of Plan Net gain on sale of other real estate owned Gains (Losses) on Sales of Other Real Estate Credit loss reduction Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Credit Loss Expense (Reversal) Interest income Interest and Dividend Income, Operating [Abstract] Total non-interest expense Non-interest expense Noninterest Expense Payment Deferral Payment Deferral [Member] Mortgage Servicing Rights Transfers and Servicing of Financial Assets, Policy [Policy Text Block] Allowance for Credit Losses Allowance for Credit Losses [Text Block] Interest on deposits Interest Expense, Deposits Property, Plant and Equipment by Type [Axis] Long-Lived Tangible Asset [Axis] Schedule of Available For Sale, Held-to-Maturity, and Restricted Equity Securities Schedule of Available For Sale Held to Maturity and Restricted Equity Securities [Table Text Block] Tabular presentation of available for sale securities, held-to-maturity securities and restricted equity securities as of the balance sheet date. Non-interest income Noninterest Income [Abstract] Receive Fixed, Pay Variable Receive Fixed, Pay Variable [Member] Receive Fixed, Pay Variable Other assets Other Assets, Miscellaneous Retained earnings from prior two years available for dividends Retained Earnings From Prior Two Years Available For Dividends The amount of retained earnings as of the balance sheet date from the prior two years that can be distributed in the form of dividends. Expected future benefit payments in 2027 Defined Benefit Plan, Expected Future Benefit Payment, Year Two Entity Central Index Key Entity Central Index Key PEO Name PEO Name Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Schedule of Credit Quality Risk Ratings for Loans Financing Receivable Credit Quality Indicators [Table Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Loans originated for resale Payment for Origination, Loan, Mortgage, Held-for-Sale State franchise tax State and Local Income Tax Expense (Benefit), Continuing Operations For capital adequacy purposes Banking Regulation, Tier 1 Leverage Capital, Capital Adequacy, Minimum Total unfunded commitments related to investments in tax credit structures Investment Program, Proportional Amortization Method, Elected, Commitment Carrying value Servicing Asset at Amortized Cost, Fair Value Actual (in hundredths) Common Equity Tier One Capital to Risk-Weighted Assets Common Equity Tier One Capital to Risk-Weighted Assets Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category For capital adequacy purposes (in hundredths) Banking Regulation, Tier 1 Risk-Based Capital Ratio, Capital Adequacy, Minimum Net transfer from loans to other real estate owned Real Estate Owned, Transfer from Real Estate Owned Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Expected tax expense at statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Amortization of tax credit investments Effective Income Tax Rate Reconciliation, Tax Credit, Amortization of Tax Credit Investments, Percent Effective Income Tax Rate Reconciliation, Tax Credit, Amortization of Tax Credit Investments, Percent Statement of Financial Position Location, Balance [Axis] Statement of Financial Position Location, Balance [Axis] Real estate acquired in settlement of loans Real Estate Acquired Through Foreclosure Vesting [Domain] Vesting [Domain] Retirement Benefits, Description [Abstract] Retirement Benefits, Description [Abstract] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Entity Address, Address Line One Entity Address, Address Line One Loans Held for Sale Financing Receivable, Held-for-Sale [Policy Text Block] Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] Repurchase agreements Assets Sold under Agreements to Repurchase, Repurchase Liability Mortgage servicing rights Mortgage Servicing Rights Gross Gross amount, as of the balance sheet date, of mortgage servicing rights. Total credit loss expense Credit loss expense Credit loss (reduction) expense Credit Loss, Expense (Reversal) Credit Loss, Expense (Reversal) Due in year three maturity Federal Home Loan Bank, Advance, Maturity, Year Three Revolving Loans Converted to Term Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan, Writeoff Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Allowance for credit losses: Off-Balance-Sheet, Credit Loss, Liability [Roll Forward] Capital Purchase Program Capital Purchase Program [Member] Capital Purchase Program [Member] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Financial Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Other Other Loans [Member] Other Loans Other Liabilities Other Liabilities [Member] Fair Value as of Grant Date Award Grant Date Fair Value Capital conservation buffer, minimum Capital Conservation Buffer Phase in Minimum Capital Conservation Buffer Phase in Minimum Year Five Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Changes in unrecognized tax benefits Effective Income Tax Rate Reconciliation, Tax Contingency, Amount Salaries and employee benefits Labor and Related Expense Loan Modifications Loan Modifications [Policy Text Block] Loan Modifications Allowance for loan losses as a percent of total loans Allowance for Loan Losses of Total Loans, Percentage Allowance for Loan Losses of Total Loans, Percentage Premises and equipment, net Premises and equipment, net Property, Plant And Equipment And Operating Lease Right-Of-Use Asset, Net Of Accumulated Depreciation And Amortization Property, Plant And Equipment And Operating Lease Right-Of-Use Asset, Net Of Accumulated Depreciation And Amortization For capital adequacy purpose (in hundredths) Banking Regulation, Tier 1 Leverage Capital Ratio, Capital Adequacy, Minimum Grants during the period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Unrecognized compensation costs Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Fair Value (Less than 12 months) Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Actual (in hundredths) Banking Regulation, Tier 1 Risk-Based Capital Ratio, Actual Certificates of Deposit Deposit Liabilities Disclosures [Text Block] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Schedule of Nonaccrual Loans Financing Receivable, Nonaccrual [Table Text Block] 2027 Lessee, Operating Lease, Liability, to be Paid, Year Two Condensed Financial Information Disclosure [Abstract] Condensed Financial Information Disclosure [Abstract] Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Investments Investments Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Expected future benefit payments in 2028 Defined Benefit Plan, Expected Future Benefit Payment, Year Three Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration] Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration] Schedule of Accumulated Post-retirement Benefit Obligation and Funded Status Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan [Table Text Block] Nondeductible interest expense Effective Income Tax Rate Reconciliation, Nondeductible Interest Expense, Amount Effective Income Tax Rate Reconciliation, Nondeductible Interest Expense, Amount 2024 Year Awarded 2024 [Member] Year Awarded 2024 Non-PEO NEO Non-PEO NEO [Member] Total Advance from Federal Home Loan Bank Core deposit intangible DeferredTaxAssetIntangibleLiabilities DeferredTaxAssetIntangibleLiabilities Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Notional value Derivative Liability, Notional Amount Land Land [Member] Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Award Type [Domain] Award Type [Domain] Award Type [Domain] 2026 Lessee, Operating Lease, Liability, to be Paid, Year One Equity Awards Adjustments Equity Awards Adjustments [Member] Weighted average discount rate as of December 31 Weighted average discount rate as of December 31 Weighted average discount rate. Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Effect of cross-border tax laws Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Percent Compensation Amount Outstanding Recovery Compensation Amount To be well-capitalized under prompt corrective action provisions Banking Regulation, Total Risk-Based Capital, Well Capitalized, Minimum Term Term Loan [Member] The catagory of loans which are designated to individuals for a residence that typically includes traditional amortizing home mortgages. Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Estimate fair value Estimate of Fair Value Measurement [Member] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Amortized Cost, Due in 1 to 5 years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Foreign tax effects Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent Net unrecognized post-retirement benefits included in accumulated other comprehensive income Defined Benefit Plan, Expected Amortization, Next Fiscal Year Service charges on deposit accounts Deposit Account [Member] 2029 Time Deposit Maturities, Year Four Certificates of deposit less than $100,000 Time Deposits, Less than $100,000 Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Net deferred loan costs included in loan balances Financing Receivable, Deferred Commitment Fee Amortized Cost, Due in 5 to 10 years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Carrying value of investments Investment, Proportional Amortization Method, Elected, Amount Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Interest Rate Swap January 01 2026 Interest Rate Swap January 01 2026 [Member] Interest Rate Swap January 01 2026 Financial Instruments [Domain] Financial Instruments [Domain] Fair Value (Estimated), Due after 10 years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Total deferred tax liability Deferred Tax Liabilities, Gross Award Date [Domain] Award Date [Domain] Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Other nontaxable income and nondeductible expenses Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Combination Payment Deferral and Term Extension Extended Maturity and Payment Deferral [Member] Extended Maturity and Payment Deferral Banking Regulation, Regulatory Capital Requirement, Compliance [Table] Banking Regulation, Regulatory Capital Requirement, Compliance [Table] Minimum Minimum [Member] Net interest income after provision for credit losses Interest Income (Expense), after Provision for Loan Loss Loan-to-value percent, commercial real estate Commercial Real Estate Loans Maximum Loan To Value The maximum percentage of loan to value for commercial real estate loans based on current appraisal information. Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Company Selected Measure Name Company Selected Measure Name Fair Value Measurement [Domain] Fair Value Measurement [Domain] Post-retirement benefit plan health insurance subsidy range minimum per month per person Post Retirement Benefit Plan Health Insurance Subsidy Range Minimum The minimum amount employer will contribute per month to post-retiree for subsidizing the cost of health care insurance. For capital adequacy purposes Banking Regulation, Total Risk-Based Capital, Capital Adequacy, Minimum Borrowed Funds Debt Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Operating cash flows from operating leases Operating Lease, Payments Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Dividends payable Dividends Payable Diluted EPS: Income available to common shareholders plus assumed conversions Net Income (Loss) Available to Common Stockholders, Diluted Amortized Cost, Due after 10 years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10 Collateral [Domain] Collateral Held [Domain] Shareholders' equity Stockholders' Equity Note [Abstract] Loans more than 90 days past due accruing interest 90 Plus Days And Accruing Financing Receivable, 90 Days or More Past Due, Still Accruing Number of shares available to directors and employees for stock purchase or savings and investment plans (in shares) Number Of Shares Available For Grant Under Employee Savings and Investment Plan The number of shares of common stock available to sold to directors and employees under stock purchase or savings and investment plan. Goodwill Deferred Tax Liabilities, Goodwill Off-Balance-Sheet Financial Credit Exposures and Contractual Obligations Commitments and Contingencies Disclosure [Text Block] Diluted EPS: Income available to common shareholders plus assumed conversions (in shares) Weighted Average Number of Shares Outstanding, Diluted Losses charged to allowance Real Estate Owned, Valuation Allowance, Amounts Applied Segments Segment Reporting, Policy [Policy Text Block] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Derivative [Table] Derivative [Table] Entity Small Business Entity Small Business Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Other operating expense Other Cost and Expense, Operating Investment in flow through entities Deferred Tax Assets, Investment in Limited Partnership Deferred Tax Assets, Investment in Limited Partnership Document Transition Report Document Transition Report Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Fair Value (Estimated), Due in 1 to 5 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Total Finance Lease, Liability, to be Paid Underlying Securities Award Underlying Securities Amount Repayment on long-term borrowings Repayments of Other Long-Term Debt Change in unamortized net actuarial gain Other Comprehensive Income (Loss), before Reclassifications, before Tax Equity Component [Domain] Equity Component [Domain] 2027 Finance Lease, Liability, to be Paid, Rolling Year Two Document Period End Date Document Period End Date Schedule of Activity in the ACL for Held-to-maturity Debt Securities Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Table Text Block] Amortization of tax credit investments Effective Income Tax Rate Reconciliation, Tax Credit, Amortization of Tax Credit Investments, Amount Effective Income Tax Rate Reconciliation, Tax Credit, Amortization of Tax Credit Investments, Amount Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] Subsequent Events Subsequent Events, Policy [Policy Text Block] Income Taxes Income Tax Disclosure [Text Block] Net (decrease) increase in certificates of deposit Increase (Decrease) in Time Deposits To be well-capitalized under prompt corrective action provisions (in hundredths) Common Equity Tier One Risked Based Capital Required to be Well Capitalized to Risk-Weighted Assets Common Equity Tier One Risked Based Capital Required to be Well Capitalized to Risk-Weighted Assets Accrual of Interest Income and Expense Accrual of Interest Income and Expense [Policy Text Block] Disclosure of accounting policy for recognizing interest income and expense, including the method of accrual of income and expense on loans. Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Document Type Document Type Level 3 Level 3 Level 3 Fair Value, Inputs, Level 3 [Member] Earnings Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Advertising and marketing expense Marketing and Advertising Expense Additional paid-in capital Additional paid-in capital Additional Paid in Capital Product and Service [Axis] Product and Service [Axis] Revolving Loans Amortized Cost Basis Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff Number of shares registered with SEC for dividend reinvestment plan (in shares) Number of shares registered pursuant to dividend reinvestment plan Number of shares registered with the Securities and Exchange Commission from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity. Interest rate, due in year five and thereafter Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Five And Thereafter Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Five And Thereafter Proceeds from sales and transfers of loans Proceeds from Sale, Loan, Held-for-Sale Statistical Measurement [Axis] Statistical Measurement [Axis] Defined contribution plan [Abstract] Defined Contribution Plan [Abstract] Year Two Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff Fixed Rate Paid Derivative, Fixed Interest Rate Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Impairment losses Restricted Equity Securities Unrealized Losses As of the balance sheet date, the excess of carrying value (amortized cost) over fair value of a security categorized as non marketable securities, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding loss. Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Average assets Banking Regulation, Leverage Ratio [Abstract] Basic EPS: Income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Share Repurchase Program [Domain] Share Repurchase Program [Domain] Other comprehensive gain (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Derivative Financial Instruments Designated as Hedges Derivatives, Methods of Accounting, Hedging Derivatives [Policy Text Block] Interest income which would have been recognized on loans Loans and Leases Receivable, Interest Income Lost On Loans Loans and Leases Receivable, Interest Income Lost On Loans Level 1 Level 1 Level 1 Fair Value, Inputs, Level 1 [Member] Net loans and loans held for sale Loans And Lease Receivable Net Reflects the aggregate carrying amount of all categories of loans and leases held in portfolio for investment and held for sale, net of unearned income and the allowance for losses on loans and leases. Some loans are stated at the lower of cost or market, or elected fair value. Diluted earnings per common share (usd per share) Diluted EPS: Income available to common shareholders plus assumed conversions (usd per share) Diluted earnings per share (usd per share) Earnings Per Share, Diluted FDIC insurance premiums Federal Deposit Insurance Corporation Premium Expense Other tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount Multifamily Multifamily [Member] Allowance for credit losses: Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Roll Forward] Fair Value (Estimated), Due in 1 to 5 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 ATM and interchange expense ATM and interchange expense Fees incurred from processing ATM and debit card transaction fees. Accumulated Other Comprehensive Income (Loss) [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Recoveries Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Allowance for Credit Loss, Recovery $100,000 and Greater Greater Than $100,000 [Member] -- None. No documentation exists for this element. -- Amortized Cost Basis Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount Schedule of Maturities of Certificates of Deposit Schedule Of Maturities Of Time Deposits [Table Text Block] The tabular disclosure of the contractual maturities of time deposits. Commercial Loan Commercial Loan [Member] Domestic State Income Taxes Paid Income Tax Paid, State and Local, after Refund Received Derivative Liability, Statement of Financial Position [Extensible Enumeration] Derivative Liability, Statement of Financial Position [Extensible Enumeration] Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Increase in dividends receivable Increase (Decrease) in Dividends Receivable Auditor Location Auditor Location Core Deposits Core Deposits [Member] Loan maturities Financing Receivable, Term Financing Receivable, Term Mortgage servicing rights capitalized Servicing Asset at Fair Value, Additions Term Extension Extended Maturity [Member] Payment for repurchase of common stock Stock Repurchased and Retired During Period, Value Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] For capital adequacy purposes Common Equity Tier One Capital Required for Capital Adequacy Purposes Common Equity Tier One Capital Required for Capital Adequacy Purposes Deferred tax expense at 21% Defined Benefit Plan, Future Deferred Tax Benefit Defined Benefit Plan, Future Deferred Tax Benefit Unamortized gain Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Comprehensive Income (Loss) Comprehensive Income, Policy [Policy Text Block] Borrowed Funds [Abstract] Borrowed Funds [Abstract] -- None. No documentation exists for this element. -- Maturities Of Certificates Of Deposits By Balance [Axis] Maturities Of Certificates Of Deposits By Balance [Axis] The disclosure of maturities of time deposits by stated value. Less: imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount 2026 Time Deposit Maturities, Year One Total Income Taxes Paid Income Taxes Paid, Net Other nontaxable income and nondeductible expenses Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent Commitments to extend credit Commitments to Extend Credit [Member] New loans Loans and Leases Receivables, Related Parties, Additions, Aggregated Over 60,000 Dollars Loans and Leases Receivables, Related Parties, Additions, Aggregated Over 60,000 Dollars Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Number of securities temporarily impaired (security) Number Of Securities Temporarily Impaired The number of securities with unrealized losses, classified as temporarily impaired, held in a Company's portfolio as of the balance sheet date. Premises and Equipment Property, Plant and Equipment Disclosure [Text Block] Total undiscounted lease payments Lessee, Operating Lease, Liability, to be Paid Net unrealized gain (loss) on securities available for sale, net of taxes Net unrealized (loss) gain on securities available for sale, net of tax Net unrealized (loss) gain on securities available for sale OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Schedule of Actual and Minimum Capital Amounts and Ratios Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Loans Total Total Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Schedule of Fair Value, Off-balance Sheet Risks [Table] Fair Value, off-Balance-Sheet Risk [Table] Repurchase agreements for municipal and commercial customers Securities Sold under Agreements to Repurchase Schedule of Temporary Impairment Losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Expiration Date Trading Arrangement Expiration Date Schedule of Net Periodic Benefit Cost Not Yet Recognized Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block] Net (decrease) increase in other liabilities Increase (decrease) in other liabilities Increase (Decrease) in Other Operating Liabilities Less allowance for credit losses HTM allowance for credit losses Beginning balance Total ending allowance balance Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Total loans Risk-rated [Member] Risk-rated Construction Construction Loans [Member] Entity Current Reporting Status Entity Current Reporting Status Increase in dividends payable Increase (decrease) dividends payable Increase (decrease) dividends payable Receivables [Abstract] Receivables [Abstract] Derivative [Line Items] Derivative [Line Items] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] Collateral [Axis] Collateral Held [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Amortized Cost, Due in 1 year or less Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Expected tax expense at statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Audit Information [Abstract] Audit Information [Abstract] Audit Information Financial Instrument [Axis] Financial Instrument [Axis] Balance Sheets Statement of Financial Position [Abstract] Executive Category: Executive Category [Axis] Unrealized Losses (12 months or more) Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Loans Financing Receivable [Policy Text Block] State and local taxes, net of federal tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Current Fiscal Year End Date Current Fiscal Year End Date Unrealized Losses (Less than 12 months) Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Total deposits Deposits Deposits Number of mortgage loans in the process of foreclosure Mortgage Loans in Process of Foreclosure, Number Mortgage Loans in Process of Foreclosure, Number Federal Home Loan Bank Stock Federal home loan bank stock Federal Home Loan Bank Stock Total liabilities Derivative Liability Pay Fixed, Receive Variable Pay Fixed, Receive Variable [Member] Pay Fixed, Receive Variable Historical tax credits Effective Income Tax Rate Reconciliation, Historical Tax Credits, Percent Effective Income Tax Rate Reconciliation, Historical Tax Credits, Percent Post-retirement benefit plan health insurance subsidy range maximum per month per person Post Retirement Benefit Plan Health Insurance Subsidy Range Maximum The maximum amount employer will contribute per month to post-retiree for subsidizing the cost of health care insurance. Other operating expense Other Noninterest Expense Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] 2030 Finance Lease, Liability, to be Paid, Rolling Year Five Pass (risk rating 1-5) Pass [Member] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Unrealized Losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Effect of changes in tax laws or rates enacted in the current period Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Schedule of Assets and Liabilities Measured on Recurring Basis Measured at Fair Value Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Cash and Cash Equivalents [Abstract] Cash and Cash Equivalents [Abstract] Shares (Denominator) Weighted Average Number of Shares Outstanding, Diluted [Abstract] Real Estate Non-Owner Occupied Real Estate Loan, Non-Owner Occupied [Member] Real Estate Loan, Non-Owner Occupied Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-Maturity Securities [Line Items] Due in twelve months maturity Federal Home Loan Bank, Advance, Maturity, Year One Schedule of Past Due Loans Aging Financing Receivable, Past Due [Table Text Block] Number of shares available for future use under employee savings and investment plan (in shares) Number Of Shares Available For Future Use Under Employee Savings And Investment Plan Total number of shares of common stock available for future use. Net cash (used) provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Measure: Measure [Axis] Schedule of Other Operating Income and Expense Schedule Of Other Operating Income And Expense [Table Text Block] Tabular disclosure of each detailed component of other operating income and expense that are applicable, but not separately disclosed in the income statement. Credit loss expense - loans Financing Receivable, Credit Loss, Expense (Reversal) Total share based compensation cost Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Recognized And Not yet Recognized Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Recognized And Not yet Recognized Loan adjustments Fair Value Derivative, Fair Value, Net Tier 1 capital to average assets Banking Regulation, Tier 1 Leverage Capital [Abstract] Schedule of Right-of-use Asset and Lease Liability Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee Unfunded, supplemental retirement benefits payable period Post Employment Plan, Supplemental Benefits, Payment Period Upon Retirement Or Death Post Employment Plan, Supplemental Benefits, Payment Period Upon Retirement Or Death Outstanding loans and commitments subject by independent consulting firm Financing Receivable, Outstanding Loans And Commitments Subject By Independent Consulting Firm Percentage of loans and commitments subject to review by an independent consulting firm each year. Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] Securities to be held to maturity Debt Securities, Held-to-Maturity, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract] Consumer Consumer Consumer Portfolio Segment [Member] Number of acquisitions Business Combination, Number of Businesses Acquired Total expense Total expense Total expense at parent level Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Tier 2 capital to risk-weighted assets Banking Regulation, Total Capital [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Consolidated Consolidated [Member] The actual and minimum capital amounts and ratios for the bank presented on a consolidated basis. Common stock and additional paid-in capital Common Stock Including Additional Paid in Capital [Member] Entity Tax Identification Number Entity Tax Identification Number Credit loss reduction - debt securities HTM Debt Securities, Held-to-Maturity, Credit Loss Expense (Reversal) Year Four Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff Number of shares issued (in shares) Common Stock, Shares, Issued Derivative Asset, Statement of Financial Position [Extensible Enumeration] Derivative Asset, Statement of Financial Position [Extensible Enumeration] Operating lease weighted average remaining lease term (years) Operating Lease, Weighted Average Remaining Lease Term Allowance for Loan and Lease Losses [Roll Forward] Allowance for Loan and Lease Losses [Roll Forward] Entity Public Float Entity Public Float Interest Rate Swap March 01 2026 Interest Rate Swap March 01 2026 [Member] Interest Rate Swap March 01 2026 Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Securities charged-off Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Unamortized net actuarial gain Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Security Exchange Name Security Exchange Name Net increase in loans Payments to Acquire Finance Receivables Goodwill and intangible asset impairment Goodwill and Intangible Asset Impairment Mortgage-backed securities Mortgage-backed securities Collateralized Mortgage-Backed Securities [Member] Number of shares issued during period, dividend reinvestment plan (in shares) Stock Issued During Period, Shares, Dividend Reinvestment Plan Weighted average discount rate for net periodic cost Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Due thereafter Federal Home Loan Bank, Advance, Maturity, Year Five and Thereafter Federal Home Loan Bank, Advance, Maturity, Year Five and Thereafter Statement [Line Items] Statement [Line Items] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Interest Rate Swap March 01 2027 Interest Rate Swap March 01 2027 [Member] Interest Rate Swap March 01 2027 Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Effect of dilutive securities: restricted stock (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) [Abstract] Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Statistical Measurement [Domain] Statistical Measurement [Domain] Unallocated Unallocated Financing Receivables [Member] Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Schedule of Balance Sheets Condensed Balance Sheet [Table Text Block] Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement Of Income Or Comprehensive Income, Extensible List, Not Disclosed Flag Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement Of Income Or Comprehensive Income, Extensible List, Not Disclosed Flag Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement Of Income Or Comprehensive Income, Extensible List, Not Disclosed Flag Construction loans, percent of capital Construction Loans Actual Loan Portfolio To Company Capital The ratio of loan portfolio to Company capital for construction loans . Securities pledged as collateral Debt Securities, Available-for-Sale, Restricted Tax Jurisdiction of Domicile [Extensible Enumeration] Tax Jurisdiction of Domicile [Extensible Enumeration] Interest rate swap agreements Interest Rate Swap [Member] Number of shares issued under employee savings and investment plan (in shares) Number Of Shares Issued Under Employee Savings and Investment Plan The number of shares issued under employee savings and investment plan. Other Operating Income and Expense Other Income and Other Expense Disclosure [Text Block] Pledged Status [Axis] Pledged Status [Axis] Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Basic earnings per common share (usd per share) Basic EPS: Income available to common shareholders (usd per share) Basic earnings per share (usd per share) Earnings Per Share, Basic Debt securities, held-to-maturity, nonaccrual Debt Securities, Held-to-Maturity, Nonaccrual Number of shares of common stock reserved for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Amount of claims under review by management Financing Receivables, Subject To Annual Internal Credit Review Financing Receivables, Subject To Annual Internal Credit Review Award Date [Axis] Award Date [Axis] Changes in unrecognized tax benefits Effective Income Tax Rate Reconciliation, Tax Contingency, Percent Net change Other Comprehensive Income (Loss), Net of Tax Anticipated loan prepayment rate of servicing assets (in hundredths) Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed Borrowed funds – short term Short-Term Debt 2030 Time Deposit Maturities, Year Five Home Equity Home Equity Line of Credit Portfolio [Member] Home Equity Line of Credit Portfolio [Member] Unrealized Gains Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain 2023 Year Awarded 2023 [Member] Year Awarded 2023 Schedule of Assets Measured on Nonrecurring Basis Measured at Fair Value Fair Value Measurements, Nonrecurring [Table Text Block] Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption [Domain] Balloon payment term Financing Receivable, Modified, Payment Deferral, Period Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization Of Gain (Loss), Statement Of Income Or Comprehensive Income, Extensible List, Not Disclosed Flag Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization Of Gain (Loss), Statement Of Income Or Comprehensive Income, Extensible List, Not Disclosed Flag Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization Of Gain (Loss), Statement Of Income Or Comprehensive Income, Extensible List, Not Disclosed Flag Total Chargeoffs Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Accounts and Financing Receivables [Table] Accounts and Financing Receivables [Table] Interest rate, due in next twelve months Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Next Twelve Months Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Next Twelve Months NOW deposits Deposits, Negotiable Order of Withdrawal (NOW) Compensation expense recognized for restricted shares Share-Based Payment Arrangement, Expense Hedging Designation [Domain] Hedging Designation [Domain] Loans held for sale Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance Total liabilities and shareholders' equity Liabilities and Equity Accumulated amortization Accumulated Amortization Mortgage Servicing Rights The cumulative amount of amortization for mortgage servicing rights that has been recognized in the income statement. To be well-capitalized under prompt corrective action provisions Common Equity Tier One Risk Based Capital Required to be Well Capitalized Common Equity Tier One Risk Based Capital Required to be Well Capitalized Other assets Deferred Tax Assets, Other Accounting Policies [Abstract] Accounting Policies [Abstract] Schedule of Future Lease Payments for Operating Leases Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Outstanding principal balance of loans serviced for others Residential Mortgage Loans Serviced For Others Outstanding Principal Dollar amount of principal outstanding on loans being serviced for others at the balance sheet date. Year One Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Pay vs Performance Disclosure [Line Items] U.S. Government-sponsored agencies US Government Agencies Debt Securities [Member] To be well-capitalized under prompt corrective action provisions (in hundredths) Banking Regulation, Tier 1 Leverage Capital Ratio, Well Capitalized, Minimum Net lease liability Operating Lease, Liability Other settlement income Defined Benefit Plan, Other Settlement Expense Defined Benefit Plan, Other Settlement Expense 90+ Days Past Due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Liabilities Liabilities [Abstract] Acquisitions and Intangible Assets Business Combination [Text Block] Interest rate, Repurchase agreements for municipal and commercial customers Securities Sold under Agreements to Repurchase, Stated Rate Securities Sold under Agreements to Repurchase, Stated Rate Payment Status (Amortized Cost Basis) Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default Financing receivable term extension Financing Receivable, Threshold Period Past Due Regulatory Capital Requirements Regulatory Capital Requirements under Banking Regulations [Text Block] Year Three Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Statements of Cash Flows Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount 2028 Lessee, Operating Lease, Liability, to be Paid, Year Three Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff To be well-capitalized under prompt corrective action provisions (in hundredths) Banking Regulation, Tier 1 Risk-Based Capital Ratio, Well Capitalized, Minimum Comprehensive income Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Name Measure Name Fair Value (Estimated), Due in 1 year or less Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Provision Real Estate Owned, Valuation Allowance, Provision Proceeds from maturities, payments, calls of securities available for sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Schedule of Financing Receivable, Modified, Subsequent Default Financing Receivable, Modified, Subsequent Default [Table Text Block] Real Estate Owned, Disclosure of Detailed Components [Abstract] Real Estate Owned, Disclosure of Detailed Components [Abstract] Interest and fees on loans (tax-exempt income) Interest Income and Fees on Loans Tax Exempt Interest Income and Fees on Loans Tax Exempt Securities available for sale Available-for-Sale Securities, Debt Maturities [Abstract] Borrowed funds – long term Long-Term Debt Legal Entity [Axis] Legal Entity [Axis] Total assets Assets Schedule of Statements of Cash Flows Condensed Cash Flow Statement [Table Text Block] Schedule of Nonvested Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Allowance for credit losses Deferred Tax Asset, Tax Deferred Expense, Reserve and Accrual, Financing Receivable, Allowance for Credit Loss Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Net unrealized gain on postretirement costs Net unrecognized post-retirement benefits included in accumulated other comprehensive income Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Income Taxes Income Tax, Policy [Policy Text Block] Cash flows from operating activities Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Intangible assets useful life Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Restricted equity securities Equity Securities, Restricted [Abstract] Number of post-retirement benefit plans Number Of Post Retirement Benefit Plans Number of post-retirement benefit plans sponsored by the company. Interest on borrowed funds Interest Expense, Borrowings 2027 Time Deposit Maturities, Year Two For capital adequacy purposes (in hundredths) Banking Regulation, Total Risk-Based Capital Ratio, Capital Adequacy, Minimum Securities to be held to maturity (net of ACL) Fair Value (Estimated) Securities to be held to maturity, Fair Value (Estimated) Securities to be held to maturity (net of allowance for credit losses) Debt Securities, Held-to-Maturity, Fair Value Cash dividends declared (usd per share) Common Stock, Dividends, Per Share, Declared Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Unrealized loss on securities transferred from available for sale to held to maturity DeferredTaxAssetSecuritiesTransferedfromAFStoHTM DeferredTaxAssetSecuritiesTransferedfromAFStoHTM Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Adoption of ASU No. 2016-13 Impact of adopting ASC 326 Cumulative Effect, Period of Adoption, Adjustment [Member] Level 2 Level 2 Level 2 Fair Value, Inputs, Level 2 [Member] Fair Value (Estimated), Due in 1 to 5 years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Document Financial Statement Error Correction Document Financial Statement Error Correction [Flag] State and local taxes, net of federal tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Investment in subsidiary Equity Method Investments Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Business Combination [Domain] Business Combination [Domain] Fair value of securities transferred Available-for-Sale Securities, Transferred Security, at Fair Value Available-for-Sale, Transferred Security, at Fair Value Low Income Housing tax credits Effective Income Tax Rate Reconciliation, Low Income Housing Tax Credits, Percent Effective Income Tax Rate Reconciliation, Low Income Housing Tax Credits, Percent Number of states Number Of States in New England Where FHLB Serve The number of States in New England where Federal Home Loan Bank do housing and financing services. Loans pledged as collateral Asset Pledged as Collateral [Member] Schedule of Current and Deferred Components of Income Tax Expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Plan Name [Axis] Plan Name [Axis] Premises and Equipment Property, Plant and Equipment, Policy [Policy Text Block] PEO PEO [Member] Actual Banking Regulation, Tier 1 Leverage Capital, Actual Schedule of Contractual Maturities of Investment Securities Investments Classified by Contractual Maturity Date [Table Text Block] Non-cash transactions: Noncash Investing and Financing Items [Abstract] Loss before income taxes and Bank earnings Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Servicing assets and servicing liabilities at fair value, assumptions used to estimate fair value, discount rate adjustment factor (in hundredths) Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Discount Rate Adjustment Factor The amount of rate spread added to the ten-year US Treasury rate to derive the discount rate used in the fair value calculation for the loan servicing portfolio. Land improvements Land Improvements [Member] Changes in valuation allowances Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Depreciation Deferred Tax Liabilities, Property, Plant and Equipment Derivative Swap Type [Axis] Derivative Swap Type [Axis] Derivative Swap Type Certificates of deposit Total Local certificates of deposit Time Deposits Retained earnings Retained Earnings [Member] Schedule of Quarterly Information Quarterly Financial Information [Table Text Block] Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Income and Comprehensive Income Statements Income Statement [Abstract] Cash and cash equivalents Cash and cash equivalents at beginning of year Cash and cash equivalents at end of year Cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Total interest rate agreements Derivative Asset Funded status Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] Fair Value (12 months or more) Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Unrealized gains (losses) arising during the year Unrealized losses on cash flow hedging derivatives arising during the year OCI, before Reclassifications, before Tax, Attributable to Parent Agriculture Agriculture Loan [Member] Agriculture Loan Fair Value, Measurements, Nonrecurring Fair Value, Nonrecurring [Member] Maturity Of Certificates Of Deposit By Balance [Domain] Maturity Of Certificates Of Deposit By Balance [Domain] -- None. No documentation exists for this element. -- Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Modified [Table] Federal Reserve Bank Stock Federal reserve bank stock Federal Reserve Bank Stock Credit loss reduction - off-balance sheet credit exposures Credit loss reduction Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) Product and Service [Domain] Product and Service [Domain] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Business Combination [Table] Business Combination [Table] OREO Deferred Tax Assets, Other Real Estate Owned Deferred Tax Assets, Other Real Estate Owned Notional Amount Notional amount Derivative, Notional Amount Certificates $100,000 to $250,000 Time Deposits Greater Than 100000 And Less Than 250000 The aggregate amount of domestic or foreign time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to more than $100,000 but less than $250,000. Tax exempt income Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Revolving Loans Amortized Cost Basis Financing Receivable, Excluding Accrued Interest, Revolving Accounting Standards Update [Extensible List] Accounting Standards Update [Extensible Enumeration] City Area Code City Area Code Schedule of Allowance for Credit Losses by Class of Financing Receivable and Allowance Financing Receivable, Allowance for Credit Loss [Table Text Block] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Schedule of Composition of Loan Portfolio Schedule Of Composition Of Loan Portfolio [Table Text Block] Tabular disclosure of the composition of loans contained in the loan portfolio. Loan Fees and Costs Financing Receivable, Fee and Interest Income [Policy Text Block] Cash flows from investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Historical tax credits Effective Income Tax Rate Reconciliation, Historical Tax Credits, Amount Effective Income Tax Rate Reconciliation, Historical Tax Credits, Amount Schedule of Other Real Estate Owned Other Real Estate Owned [Table Text Block] Tabular disclosure of real estate owned and acquired in settlement of troubled loans through surrender or foreclosure. Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] Accrued interest receivable Interest Receivable Defined contribution plan, employer matching contribution, percent of match Defined Contribution Plan, Employer Matching Contribution, Percent of Match Fair Value Hedges Fair Value Hedging [Member] Federal income tax Federal Income Tax Expense (Benefit), Continuing Operations [Abstract] Amortization of gains Defined Benefit Plan, Amortization of Gain (Loss) Lease expense Lease, Cost Cash Flow Hedges Cash Flow Hedging [Member] Other liabilities Other liabilities Other liabilities Other Liabilities Goodwill Goodwill Goodwill Schedule of Supplemental Lease Information Lease, Cost [Table Text Block] Financing Receivable Information by Type of Reserve [Domain] Financing Receivable Information by Type of Reserve [Domain] Type of reserves based on individual impairment, historical loss experience, or qualitative factors. Deferred Deferred Federal Income Tax Expense (Benefit) Real Estate Owner Occupied Real Estate Loan [Member] Auditor Name Auditor Name Total Borrowed funds Total Federal Home Loan Bank Advances Treasury Tax Notes And Repurchase Agreements Represents the aggregate dollar amount of all future maturities of advances from the Federal Home Loan Bank, treasury tax and loan notes and securities sold under repurchase agreements as of balance sheet date. Equipment Equipment [Member] Mortgage Servicing Rights Transfers and Servicing of Financial Assets [Text Block] Beginning balance Ending balance Related Party Loan Receivable, Aggregated Over 60,000 Dollars For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts which in aggregate exceed $60,000, due from related parties at the balance sheet date. Other Performance Measure, Amount Other Performance Measure, Amount U.S. Treasury & Agency securities US Treasury and Government [Member] Investment Securities Marketable Securities, Policy [Policy Text Block] Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Allowance for Pooled Loans Financing Receivable, Allowance for Credit Loss, Collectively Evaluated Expense Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Derivative Instrument [Axis] Derivative Instrument [Axis] Vesting [Axis] Vesting [Axis] Schedule of Off-Balance-Sheet Financial instruments Off-Balance-Sheet Financial instruments [Table Text Block] Tabular disclosure of the nature and terms of the financial instruments with off-balance sheet risk. Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Financial liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Schedule of Allowance for Loan Losses Transactions Activity In Allowance For Loan Losses By Portfolio And Segment [Table Text Block] Tabular disclosure for the roll forward of change in allowance for loan losses from period to period and related loan balances. Entity [Domain] Entity [Domain] Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Maturities Of Certificates Of Deposit [Table] Maturities Of Certificates Of Deposit [Table] -- None. No documentation exists for this element. -- Number of individual companies Number of Individual Companies in Banking Industry Number of Individual Companies in Banking Industry Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Defined contribution plan employer maximum percentage match of annual salary based on employee contribution Defined Contribution Plan Employer Maximum Percentage Match Of Employee Annual Salary The highest percentage of employer match of employee contribution to defined contribution plan based on annual salary. Maturities Of Certificates Of Deposit [Line Items] Maturities Of Certificates Of Deposit [Line Items] -- None. No documentation exists for this element. -- Operating lease asset Operating Lease, Right-of-Use Asset Credit facility with Federal Reserve Bank Credit Facility With Federal Reserve Bank Of Boston Maximum borrowing capacity under the credit facility with Federal Reserve Bank of Boston using commercial and home equity loans as collateral. Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Carrying value Reported Value Measurement [Member] Plan Name [Domain] Plan Name [Domain] Remaining Term (In Years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Fiduciary and investment management income Fiduciary and Trust [Member] Equity [Abstract] Equity [Abstract] Accumulated Net Gain (Loss) on Securities Transferred from Available-for-Sale to Held-to-Maturity Accumulated Net Gain (Loss) on Securities Transferred from Available-for-Sale to Held-to-Maturity [Member] Accumulated Net Gain (Loss) on Securities Transferred from Available-for-Sale to Held-to-Maturity [Member] Total Nonaccrual Financing Receivable, Nonaccrual Defined contribution plan service period (in months) Deferred Compensation Arrangement with Individual, Requisite Service Period Goodwill and Identified Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Buildings Building [Member] Decrease (increase) in interest-bearing deposits in other banks Interest-Bearing Deposits In Other Banks The amount outstanding of funds lent to other depository institutions, securities brokers, or securities dealers in the form of Federal Funds sold; for example, immediately available funds lent under agreements or contracts that mature in one business day or roll over under a continuing contract, regardless of the nature of the transaction or the collateral involved, excluding overnight lending for commercial and industrial purposes. Also include Federal Funds sold under agreements to resell on a gross basis, excluding (1) sales of term Federal Funds, (2) due bills representing purchases of securities or other assets by the reporting bank that have not yet been delivered and similar instruments, (3) resale agreements that mature in more than one business day involving assets other than securities, and (4) yield maintenance dollar repurchase agreements. Financial Derivative Instruments Derivatives, Policy [Policy Text Block] 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] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Total borrowed funds Debt and Lease Obligation Current Current Federal Tax Expense (Benefit) Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Doubtful (risk rating 8) Doubtful [Member] Schedule of Net Pension Costs Schedule of Net Benefit Costs [Table Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Amortization of identified intangibles Amortization of Intangible Assets Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Construction loans and non-owner-occupied commercial real estate loans, percent of capital Construction And Non Owner Occupied Commercial Real Estate Loans Portfolio To Company Capital The actual ratio of loan amount to Company capital for construction and non-owner-occupied commercial real estate. Schedule of Collateral-Dependent Loans Collateral-Dependent Loans [Table Text Block] Collateral-Dependent Loans Foreign tax effects Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Premises and equipment, gross Property, Plant And Equipment And Operating Lease Right-Of-Use Asset, Before Accumulated Depreciation And Amortization Property, Plant And Equipment And Operating Lease Right-Of-Use Asset, Before Accumulated Depreciation And Amortization Arrangement Duration Trading Arrangement Duration Risk-weighted assets Banking Regulation, Risk-Based Information [Abstract] Unrealized loss on derivative instruments Deferred Tax Assets, Derivative Instruments Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Stock Options and Stock-Based Compensation Share-Based Payment Arrangement [Text Block] Payment for repurchase of common stock (in shares) Stock Repurchased and Retired During Period, Shares Beginning balance Ending balance Off-Balance-Sheet, Credit Loss, Liability Schedule of Certificates of Deposit Time Deposits [Table Text Block] The tabular disclosure of the breakdown of the balance of time deposits. 2029 Finance Lease, Liability, to be Paid, Rolling Year Four Assets Assets Assets [Abstract] Underlying Security Market Price Change Underlying Security Market Price Change, Percent General Reserves on Loans Based on Historical Loss Experience General Reserves Based on Historical Loss Experience [Member] General reserves for types of portfolios of loans based on historical loss experience. Components of net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Loans to directors, officers and employees Loans and Leases Receivable, Related Parties Fair Value Disclosures Fair Value Disclosures [Text Block] Employee Benefit Plans Retirement Benefits [Text Block] Business Combination [Line Items] Business Combination [Line Items] Shareholders' equity Shareholders' equity Equity, Attributable to Parent [Abstract] For capital adequacy purposes (in hundredths) Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Loans and Leases Receivable, Related Parties [Roll Forward] Loans and Leases Receivable, Related Parties [Roll Forward] Schedule of Troubled Debt Restructurings on Financing Receivables Financing Receivable, Modified [Table Text Block] 30-59 Days Past Due Financial Asset, 30 to 59 Days Past Due [Member] Entity Voluntary Filers Entity Voluntary Filers Belfast, Maine Branch Belfast, Maine Branch [Member] Belfast, Maine Branch Net unrealized gains (losses) on securities transferred Available-for-sale Securities, Transferred to Held-to-maturity Securities, Accumulated Unrealized Gain (Loss) Available-for-sale Securities, Transferred to Held-to-maturity Securities, Accumulated Unrealized Gain (Loss) Valuation allowance on impaired financing receivable Impaired Financing Receivable, Related Allowance, Measured at Fair Value Impaired Financing Receivable, Related Allowance, Measured at Fair Value Amortized Cost, Due in 5 to 10 years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 5 through 10 Restricted equity securities Federal Home Loan Bank And Federal Reserve Bank stock At Cost The combined total of Federal Home Loan Bank and Federal Reserve Bank stock (FRB) which represent equity interests in the Federal Reserve Bank and the Federal Home Loan Bank. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Entity Registrant Name Entity Registrant Name Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] To be well-capitalized under prompt corrective action provisions (in hundredths) Banking Regulation, Total Risk-Based Capital Ratio, Well Capitalized, Minimum Net periodic benefit (credit) cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Municipal Bonds Municipal Bonds [Member] Interest Rate Cap July 01 2028 at 4.550% Interest Rate Cap July 01 2028 at 4.550% [Member] Interest Rate Cap July 01 2028 at 4.550% Total assets Assets, Fair Value Disclosure Deposits [Abstract] All Past Due Financial Asset, Past Due [Member] Schedule of Change in Allowance for Losses from Other Real Estate Owned Change In Allowance for Losses From Other Real Estate Owned [Table Text Block] Tabular disclosure of the change in the allowance for real estate owned and acquired in settlement of troubled loans through surrender or foreclosure during the period. Fair value of mortgage servicing rights Mortgage servicing rights Mortgage servicing rights Servicing Asset at Fair Value, Amount Net amortization of investment premiums Accretion (Amortization) of Discounts and Premiums, Investments Customer loan interest swap agreements Customer Loan Interest Swap [Member] Customer Loan Interest Swap [Member] Interest cost Defined Benefit Plan, Interest Cost Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption [Axis] Restatement Determination Date: Restatement Determination Date [Axis] Interest rate, due in year four Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Four Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Four Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Tangible book value per common share (usd per share) Tangible Book Value Per Common Share Tangible book value of common stock per share. Effect of changes in tax laws or rates enacted in the current period Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Name Trading Arrangement, Individual Name Individually analyzed loans Impaired Loans Fair Value Disclosure This element represents the fair value disclosure of impaired loans that have had a fair value adjustment since their initial recognition. Number of units Number of Units in Commercial Multifamily Properties Number of Units in Commercial Multifamily Properties Capital conservation buffer Capital Conservation Buffer Capital Conservation Buffer 2020 Plan 2020 Equity Incentive Plan [Member] 2020 Equity Incentive Plan Share Repurchase Program [Axis] Share Repurchase Program [Axis] Name Awards Close in Time to MNPI Disclosures, Individual Name Amortized Cost, Due in 1 to 5 years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year One through Five Net unrealized gain on cash flow hedging derivative instruments AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Interest Rate Cap July 01 2028 at 4.050% Interest Rate Cap July 01 2028 at 4.050% [Member] Interest Rate Cap July 01 2028 at 4.050% ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Unamortized net actuarial gain Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year Equity compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Actuarial gain Actuarial (gain) loss Actuarial (gain) loss Schedule of Future Minimum Receipts Under Lease Agreements Finance Lease, Liability, to be Paid, Maturity [Table Text Block] Schedule of Statements of Income Condensed Income Statement [Table Text Block] Auditor Firm ID Auditor Firm ID Investment Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Non Consolidated Non Consolidated [Member] The actual and minimum capital amounts and ratios for the bank presented on a non consolidated basis. Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Benefit obligation at beginning of year Benefit obligation at end of period Benefit obligation at end of period Defined Benefit Plan, Benefit Obligation Statement of Financial Position Location, Balance [Domain] Statement of Financial Position Location, Balance [Domain] Collateral posted Derivative Asset, Subject to Master Netting Arrangement, Collateral, Obligation to Return Cash Not Offset Accumulated Net Unrealized Investment Gain (Loss) AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Other tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent Interest expense Interest Expense, Operating and Nonoperating [Abstract] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Other Real Estate Owned Real Estate Owned [Text Block] Balance at beginning of year Balance at end of year Other real estate owned, valuation allowance Real Estate Owned, Valuation Allowance Purchases of securities available for sale Payments to Acquire Debt Securities, Available-for-Sale Portion to Be Recognized in Income in 2026 Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract] State and political subdivisions State and political subdivisions US States and Political Subdivisions Debt Securities [Member] Year Two Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] All Executive Categories All Executive Categories [Member] Specific Reserves on Loans Evaluated Individually Specific Reserves Evaluated Individually for Impairment [Member] Specific reserved based on evaluating each loan individually. Schedule of Components of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Other operating income Other Operating Income Common stock, one cent par value per share Common stock Common Stock, Value, Issued Year of Maturity Time Deposits, Fiscal Year Maturity [Abstract] Interest and fees on loans (includes tax-exempt income of $2,878,000 in 2025, $2,518,000 in 2024, and $1,913,000 in 2023) Interest and Fee Income, Loans and Leases Commitments and contingent liabilities Commitments and Contingencies Year One Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff Net gain from sale of loans Net gain from sale of loans Net gain from the sale of loans held for sale. Business Combination [Axis] Business Combination [Axis] Nondeductible interest expense Effective Income Tax Rate Reconciliation, Nondeductible Interest Expense, Percent Effective Income Tax Rate Reconciliation, Nondeductible Interest Expense, Percent Mortgage loans in the process of foreclosure Mortgage Loans in Process of Foreclosure, Amount New Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Text Block] Change in net unrealized loss on available for sale securities, net of tax Increase (Decrease) In Net Unrealized Gain (Loss) On Available For Sale Securities, Net Of Tax Increase (Decrease) In Net Unrealized Gain (Loss) On Available For Sale Securities, Net Of Tax Net deferred tax asset Deferred Tax Assets, Net PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Fair Value (Estimated), Due after 10 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Provision for losses on other real estate owned Other Real Estate Owned, Valuation Allowance, Provision Other Real Estate Owned, Valuation Allowance, Provision Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Table] Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Table] 60-89 Days Past Due Financial Asset, 60 to 89 Days Past Due [Member] Hedging Designation [Axis] Hedging Designation [Axis] Due in year five maturity Federal Home Loan Bank, Advance, Maturity, Year Five Mortgage loan outstanding percentage Mortgage Loan outstanding Percentage Per Annum Mortgage Loan outstanding Percentage Per Annum Unrecognized gain (loss) for post-retirement benefits, net of tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Accrued pension and post-retirement Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits And Pension The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from post-retirement benefits and pension costs, which can only be deducted for tax purposes when actual costs are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken. Percentage of loans receivable, by type Percentage of Loans Receivable, by type Reflects the break down of the gross carrying amount of all categories of loans and leases held in the portfolio, after deducting deferred income, but before deducting the allowance for losses on loans and leases as a percentage of total portfolio. Number of Positions Number of derivative instruments Derivative, Number of Instruments Held Derivative Contract [Domain] Derivative Contract [Domain] Proceeds from sale of common stock Proceeds from sale of common stock Proceeds from Issuance of Common Stock Expected future benefit payments in 2030 Defined Benefit Plan, Expected Future Benefit Payment, Year Five Due in year two maturity Federal Home Loan Bank, Advance, Maturity, Year Two All Individuals All Individuals [Member] Residential Real Estate Residential Real Estate [Member] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Reclassifications Disclosure of Reclassification Amount [Text Block] Capital expenditures Payments to Acquire Property, Plant, and Equipment Name Forgone Recovery, Individual Name Unrealized loss on derivative Unrealized Gain (Loss) on Derivatives Mortgage origination and servicing income, net of amortization Mortgage Banking [Member] Number of shares for future use (in shares) Stock Remaining under Plan, Shares, Dividend Reinvestment Plan Stock Remaining under Plan, Shares, Dividend Reinvestment Plan Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Other Real Estate Owned Financing Receivable, Real Estate Acquired Through Foreclosure [Policy Text Block] Financing receivable, individually evaluated for impairment Financing Receivable, Individually Evaluated for Credit Loss Nonaccrual with no Allowance for Credit Loss Financing Receivable, Nonaccrual, No Allowance Interest rate, due in year three Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Three Federal Home Loan Bank, Advances, Interest Rate, Maturities Summary, Due in Year Three Year Five Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-Maturity [Table] Schedule of Derivative Instruments Schedule of Derivative Instruments [Table Text Block] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Other borrowed funds Other Borrowings Real Estate Owner Occupied Real Estate Loan, Owner Occupied [Member] Real Estate Loan, Owner Occupied Commercial Commercial Portfolio Segment [Member] Quarterly Information Quarterly Financial Information [Text Block] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Title of 12(b) Security Title of 12(b) Security Credit loss expense (reduction) Financing Receivable, Excluding Accrued Interest, Credit Loss Expense (Reversal) Schedule of Range of Interest Rates and Maturity Dates of Borrowed Funds Schedule of borrowed funds of maturities and range of interest rates [Table Text Block] Tabular disclosure of the combined aggregate amount of maturities and range of interest rates of advances for each of the five years and thereafter following the date of the latest balance sheet date presented. Estimated plan expense Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Net increase in demand, savings, and money market accounts Increase (Decrease) in Demand Deposits, Savings Deposits, and Money Market Accounts Increase (Decrease) in Demand Deposits, Savings Deposits, and Money Market Accounts Furniture and equipment expense Equipment Expense Accrued pension liability Liability, Defined Benefit Pension Plan Pension expense Pension and Other Postretirement Benefits Cost (Reversal of Cost) Earnings Per Share [Abstract] 2030 Lessee, Operating Lease, Liability, to be Paid, Year Five Two Years Two Years [Member] Two Years Mortgage servicing rights Deferred Tax Liabilities, Mortgage Servicing Rights Deferred tax expense at 21% Accumulated Other Comprehensive Income Defined Benefit Plans Tax, Deferred Tax Benefit Tax effects of the increase (decrease) to accumulated comprehensive income during the period related to benefit plans. Quarterly Financial Information Disclosure [Abstract] Quarterly Financial Information Disclosure [Abstract] Year Three Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff Thereafter Finance Lease, Liability, to be Paid, after Rolling Year Five Construction loans and non-owner-occupied commercial real estate loans, maximum percent of capital Construction And Non Owner Occupied Commercial Real Estate Loans Maximum Loan Portfolio To Company Capital The regulatory maximum allowed ratio of loan portfolio to Company capital for construction and non-owner-occupied commercial real estate. One Year One Year [Member] One Year [Member] Loan to value ratio Financing Receivable, Loan to Value Ratio Financing Receivable, Loan to Value Ratio Award Timing Disclosures [Line Items] Book value per common share (usd per share) Book Value Per Common Share Book value of common stock per share. Measurement Frequency [Domain] Measurement Frequency [Domain] Advances on long-term borrowings Proceeds from Issuance of Other Long-Term Debt Common Stock Equity [Text Block] Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Income Tax Contingency [Table] Income Tax [Table] Income Tax Net loans Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Unused lines, collateralized by residential real estate Unused Lines Of Credit Residential Mortgages [Member] The unused portion of a line of credit that is available to the borrower to finance the acquisition of residential real estate. Net income Net income Net income Net income as reported Net Income (Loss) Attributable to Parent Three Years Three Years [Member] Equity-based compensation plans that vest in three years. Actual (in hundredths) Banking Regulation, Total Risk-Based Capital Ratio, Actual Number of loan classes Financing Receivables, Number Of Loan Classes Financing Receivables, Number Of Loan Classes Schedule of Actual Tax Expense from Expected Tax Expense Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Vesting Term (In Years) Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Payment to repurchase common stock Purchase of common stock Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date Reclassifications Reclassification, Comparability Adjustment [Policy Text Block] Prepaid expense Deferred Tax Liabilities, Prepaid Expenses C&I C&I Commercial And Industrial Loans [Member] Commercial And Industrial Loans Retained earnings Retained earnings Retained Earnings (Accumulated Deficit) Money market deposits Deposits, Money Market Deposits Residential Residential Portfolio Segment [Member] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Purchases of securities to be held to maturity Payments to Acquire Held-to-Maturity Securities Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Line of credit with correspondent banks and credit facility with Federal Reserve Of Boston Line Of Credit With Correspondent Banks And Credit Facility With Federal Reserve Of Boston Line Of Credit With Correspondent Banks And Credit Facility With Federal Reserve Of Boston Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Statement [Table] Statement [Table] Change in deferred taxes Deferred Income Tax Expense (Benefit) Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Cash flows from financing activities Cash flows from financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Interest Rate Swap August 01 2025 Interest Rate Swap August 01 2025 [Member] Interest Rate Swap August 01 2025 Combination Payment Deferral and Rate Mod Payment Deferral And Interest Rate Reduction [Member] Payment Deferral And Interest Rate Reduction Low Income Housing tax credits Effective Income Tax Rate Reconciliation, Low Income Housing Tax Credits, Amount Effective Income Tax Rate Reconciliation, Low Income Housing Tax Credits, Amount Schedule of Common Stock Issued Or Repurchased [Line Items] Schedule of Common Stock Issued Or Repurchased [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Less than $100,000 Less Than $100,000 [Member] -- None. No documentation exists for this element. -- All Adjustments to Compensation All Adjustments to Compensation [Member] Interest Rate Reduction Contractual Interest Rate Reduction [Member] Amendment Flag Amendment Flag Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Transfers and Servicing [Abstract] Transfers and Servicing [Abstract] Termination Date Trading Arrangement Termination Date Interest-bearing deposits in other banks Interest-bearing deposits in other banks Interest-Bearing Deposits in Banks and Other Financial Institutions Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] 2028 Time Deposit Maturities, Year Three Amount of line of credit with correspondent banks Line Of Credit With Correspondent Banks Borrowing capacity under the credit lines established with correspondent banks. Less allowance for credit losses Total Allowance for Credit Losses Total Reserves Beginning balance Ending balance Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Operating lease weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Basic EPS: Income available to common shareholders (in shares) Weighted Average Number of Shares Outstanding, Basic Schedule of Basic and Diluted Earnings per Share (EPS) Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Net acquisition amortization Amortization of Acquisition Costs Demand deposits Demand Deposit Accounts Amortization of net unrealized gains Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Sale of securities Debt Securities, Available-for-Sale, Realized Gain (Loss) Cash dividends declared Dividends, Cash Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Consolidated Entities [Axis] Consolidated Entities [Axis] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common stock, par value (usd per share) Common Stock, Par or Stated Value Per Share 2026 Finance Lease, Liability, to be Paid, Next Rolling 12 Months Cash and Cash Equivalents Cash and Cash Equivalents Disclosure [Text Block] Expected future benefit payments in 2030 through 2033 Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years Effect of cross-border tax laws Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Amount Schedule of Off-Balance Sheet Allowance Schedule Of Off-Balance Sheet Allowance [Table Text Block] Schedule Of Off-Balance Sheet Allowance Use of Estimates in Preparation of Financial Statements Use of Estimates, Policy [Policy Text Block] Actual Banking Regulation, Total Capital, Actual Dividends paid Payments of Dividends Net unrealized gain on transferred securities, net of taxes Net unrealized gain on securities transferred from available for sale to held to maturity, net of tax Net unrealized gain (loss) on securities transferred from available for sale to held to maturity Available-for-Sale Securities, Transferred to Held-to-maturity Securities, Unrealized Gain (Loss) Available-for-Sale Securities, Transferred to Held-to-maturity Securities, Unrealized Gain (Loss) Related deferred taxes Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Occupancy expense Occupancy, Net Insider Trading Arrangements [Line Items] Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year Current Financial Asset, Not Past Due [Member] AFS allowance Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest Other equity securities Equity Securities [Member] Total liabilities Liabilities % of Total Class of Financing Receivable Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage Financing Receivable Information by Type of Reserve [Axis] Financing Receivable Information by Type of Reserve [Axis] Type of reserves based on individual impairment, historical loss experience, or qualitative factors. Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Off-balance-sheet financial instruments Fair Value Disclosure, off-Balance-Sheet Risks, Amount, Liability Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Derivative Swap Type [Domain] Derivative Swap Type [Domain] Derivative Swap Type [Domain] 2010 and 2020 Equity Incentive Plan 2010 and 2020 Equity Incentive Plan [Member] 2010 and 2020 Equity Incentive Plan Savings deposits Deposits, Savings Deposits Other real estate owned Other real estate owned Other Real Estate, Foreclosed Assets, and Repossessed Assets Proceeds from sale of common stock Stock Issued During Period, Value, New Issues Asset-backed securities Asset-backed securities Asset-Backed Securities [Member] Municipal Municipal Portfolio Segment [Member] Class of loans receivable which are related to municipalities or other city governments. Schedule of Reconciliation of Mortgage Servicing Assets Reconciliation of Mortgage Servicing Rights [Table Text Block] A tabular presentation of the net mortgage servicing rights as of the balance sheet date. Proceeds from maturities, payments, calls and sales of securities held to maturity Proceeds from Maturities, Prepayments and Calls of Held-to-Maturity Securities Securities to be held to maturity (net of ACL), fair value of $315,482,000 at December 31, 2025, and $314,993,000 at December 31, 2024 Net securities to be held to maturity Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Corporate securities Corporate Debt Securities [Member] Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration] Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration] Accounting Standards Update 2016-13 [Member] UNITED STATES