PPP loan interest rate Paycheck Protection Program, Interest Rate Contractual interest rate on the Paycheck Protection Program loans. Investment securities [Policy Text Block] Investment, Policy [Policy Text Block] Significant Unobservable Inputs (Level 3) [Member] Fair Value, Inputs, Level 3 [Member] Origination fees recognized on PPP loans Paycheck Protection Program, Origination Fee Recognized Origination fee recognized in income on loans advanced under the SBA Paycheck Protection Program as part of the CARES Act. Stock price at date RSUs provisionally granted Stock Provisionally Granted During Period, Stock Price, Restricted Stock Award Stock price per share on date non-option equity instruments were provisionally granted to participants. Total noninterest income Noninterest Income Investment securities HTM Debt Securities, Held-to-maturity Outstanding balance of loans receiving payment deferrals Financing Receivable, Modifications, Outstanding Balance of Payment Deferrals Outstanding balance of loans for which payments were deferred for financing receivables modified in accordance with payment deferral guidelines outlined in the CARES Act. Allowance for loan losses Allowance for loan losses Balance, Beginning of Period Balance, End of Period Total allocated Loans and Leases Receivable, Allowance Total investments Investment securities Marketable Securities Outstanding accrued interest balance of loans receiving payment deferrals Financing Receivable, Modifications, Accrued Interest Balance of Payment Deferrals Outstanding accrued interest balance of loans for which payments were deferred for financing receivables modified in accordance with payment deferral guidelines outlined in the CARES Act. Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Other comprehensive income, net of tax: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Treasury stock, shares Treasury Stock, Shares Troubled Debt Restructured Loans, Principal Balance Financing Receivable, Troubled Debt Restructuring Risks and Uncertainties [Line Items] Concentration Risk [Line Items] Recoveries of loans charged off Proceeds, Financing Receivable, Previously Written Off, Recovery Trust Income Fiduciary and Trust Activities Income Income from services rendered by trust departments acting in a fiduciary capacity, including fees earned for (1) acting as an agent for fiduciary placement and loans and (2) custody or investment advisory services when such fees are not separately billed to the customer. This item excludes commissions and fees received for the accumulation or disbursement of funds deposited to Individual Retirement or Keogh plan accounts when such are not handled by the reporting entity's trust department. Reclassification adjustment for net gains on investment securities available-for-sale realized in net income, Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Total, Recorded Investment Impaired Financing Receivable, Recorded Investment Recent accounting pronouncements [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Current Fiscal Year End Date Current Fiscal Year End Date Financing Receivable Credit Quality Indicators [Table Text Block] Financing Receivable Credit Quality Indicators [Table Text Block] Issuance of common stock Proceeds from Issuance of Common Stock Payable date, cash dividend Dividends Payable, Date to be Paid Net interest income after provision for loan losses Interest Income (Expense), after Provision for Loan Loss Entity Address, Postal Zip Code Entity Address, Postal Zip Code Carrying Amount [Member] Reported Value Measurement [Member] Stock options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Reclassification adjustment for net gains on investment securities available-for-sale realized in net income, Before Tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Equipment expense Equipment Expense Premises and equipment, net Property, Plant and Equipment, Net Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] Available-for-sale Securities Investment Securities Debt Securities, Available-for-sale [Line Items] Total assets Assets Entity Shell Company Entity Shell Company Consolidated Statements of Changes in Stockholders' Equity Parenthetical [Abstract] Consolidated Statements of Changes in Stockholders' Equity Parenthetical [Abstract] Consolidated Statements of Changes in Stockholders' Equity Parenthetical [Abstract] Document Type Document Type Interest on borrowed funds Interest Expense, Borrowings Repayment of long-term debt Repayments of Long-term Debt Noninterest bearing Noninterest-bearing Deposit Liabilities Purchase of treasury stock, shares Treasury Stock, Shares, Acquired Scenario [Domain] Scenario [Domain] 12 Months and over, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Share-based Payment Arrangement [Abstract] Share-based Payment Arrangement [Abstract] Net gains on sales of investment securities available-for-sale Net gains on sales of investment securities available-for-sale Net gains on sales of investment securities AFS Available-for-sale Securities, Gross Realized Gain (Loss) Right-of-use operating lease assets obtained in exchange for operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Accrued interest payable Interest Payable Number of grantees Share-based Payment Arrangement, Number of Grantees Number of grantees included in the share-based payment arrangement. Financial Instrument [Axis] Financial Instrument [Axis] Document Quarterly Report Document Quarterly Report New TDRs, Pre-Modification Outstanding Recorded Investment Financing Receivable, Troubled Debt Restructuring, Premodification Commitments and Contingencies Commitments and Contingencies Class of Stock [Domain] Class of Stock [Domain] Total, Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Less than 12 Months, Gross Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Stock options exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Risks and Uncertainties [Abstract] Risks and Uncertainties [Abstract] Other expenses Other Noninterest Expense Proceeds from maturities and redemptions Proceeds from Interest bearing deposits in banks The cash inflow from the maturity and/or redemption of Interest-bearing Deposits by banks in other financial institutions including, for example, certificates of deposits. Entity File Number Entity File Number Allowance for loan losses [Policy Text Block] Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block] Allocation of Allowance for Loan Losses by Impairment Methodology [Table Text Block] Allocation of Allowance for Loan Losses by Impairment Methodology [Table Text Block] Tabular disclosure of the allowance for loan losses based on impairment methodology by class of loan. [Table Text Block] Pass [Member] Pass [Member] Unrecognized compensation expense, unvested RSUs Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Treasury stock Treasury Stock [Member] Business Segments [Axis] Segments [Axis] Document Fiscal Period Focus Document Fiscal Period Focus Loans Pledged as Collateral Loans Pledged as Collateral Financial Instruments [Domain] Financial Instruments [Domain] Total other comprehensive income Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other income Noninterest Income, Other Operating Income Reclassification adjustment for net gains on sales of investment securities available-for-sale realized in net income Reclassification adjustment for net gains on sales of investment securities available-for-sale realized in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Treasury stock at cost; 475,531 shares at June 30, 2020 and 476,268 shares at December 31, 2019 Treasury Stock, Value Other Comprehensive Income, before Tax [Abstract] Other Comprehensive Income (Loss), before Tax [Abstract] Net (decrease) increase in time deposits Increase (Decrease) in Time Deposits Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Goodwill Goodwill Segment [Domain] Segments [Domain] Statement [Line Items] Statement [Line Items] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Other Comprehensive Income (Loss), Net of Tax [Abstract] Other Comprehensive Income (Loss), Net of Tax [Abstract] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Earnings per common share Earnings Per Share, Basic Dividends [Domain] Dividends [Domain] Available-for-sale Securities [Table Text Block] Available-for-sale Securities [Table Text Block] Dividends per common share Cash dividends declared, per share Common Stock, Dividends, Per Share, Declared Risks and Uncertainties [Text Block] Risks and Uncertainties [Text Block] The entire disclosure for any risk or uncertainty existing at the date of the financial statements that make an entity vulnerable to a reasonably possible, near-term, severe impact. This disclosure informs financial statement users about the general nature of the risk associated with the uncertainty. [Text Block] Earnings per common share [Policy Text Block] Earnings Per Share, Policy [Policy Text Block] Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Plan Name [Axis] Plan Name [Axis] Amendment Flag Amendment Flag Fair Value, Assets Measured on Recurring Basis [Table Text Block] Fair Value, Assets Measured on Recurring Basis [Table Text Block] Unallocated [Member] Unallocated Financing Receivables [Member] Amortized Cost Total debt securities available-for-sale, Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Common Stock, Shares, net of treasury Common Stock, Shares, net of treasury Common Stock, Shares, Outstanding Income before provision for income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Fair Value, Inputs, Level 1 [Member] Total interest expense Interest Expense Unrecognized compensation expense, stock options Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Class of Stock [Axis] Class of Stock [Axis] Plan Name [Domain] Plan Name [Domain] Dividends declared Dividends Aggregate number of outstanding grants of RSUs and stock options Share-based Compensation Arrangement, Options and Units, Outstanding, Number Aggregate number of options and restricted stock units outstanding. Substandard [Member] Substandard [Member] Local Phone Number Local Phone Number Net decrease in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Net increase (decrease) in interest bearing deposits Net Change Interest-bearing Non-time Deposits Net Change in Interest-bearing Non-time Deposits, domestic and foreign Dividends Dividend Income, Operating Troubled Debt Restructured Loans, Number of Loans Financing Receivable, Modifications, Number of Contracts Net (decrease) increase in short-term borrowings outstanding Proceeds from (Repayments of) Short-term Debt Depreciation Depreciation, Amortization and Accretion, Net Additional paid-in capital Additional Paid in Capital Other assets Other Assets Cash dividend declared, per share Subsequent Event, Specific Amount Amount of identified subsequent event item. Due from one to five years, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost Consolidated Balance Sheets Parenthetical [Abstract] Consolidated Balance Sheets Parenthetical [Abstract] Consolidated Balance Sheets Parenthetical [Abstract] Due in one year or less, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Entity Current Reporting Status Entity Current Reporting Status Government Guarantees on Impaired Loans Government Guarantees on Impaired Loans Amount of government guarantees related to impaired loans. Balance, before amounts charged off Loans and Leases Receivable, Allowance before Write-Offs Amount of allowance to cover probable credit losses on loans and leases before considering amounts of loans and leases that have been written off during the period from both loan receivables and allowance reserve for credit loss. Dividend reinvestment plan, shares Stock Issued During Period, Shares, Dividend Reinvestment Plan Debt securities with single maturity date, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value New Accounting Pronouncements and Changes in Accounting Principles [Abstract] New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Number of PPP loans Paycheck Protection Program, Number of Loans Number of loans outstanding under the SBA Paycheck Protection Program as part of the CARES Act. Net income Net Income Net income Net Income (Loss) Attributable to Parent Net unrealized holding gains arising during the period on investment securities available-for-sale, Before Tax Amount Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, before Tax Less than 12 Months, Number of Securities Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year Common Stock Common Stock [Member] Deposits Deposits [Abstract] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Borrowed funds [Abstract] Debt and Lease Obligation [Abstract] Legal Matters and Contingencies Disclosure [Text Block] Legal Matters and Contingencies [Text Block] Other investments Other investments, mutual funds Equity Securities, FV-NI 2014 Equity Plan [Member] 2014 Equity Plan [Member] 2014 Equity Incentive Plan [Member] Entity Small Business Entity Small Business Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Statement, Scenario [Axis] Scenario [Axis] Due from one to five years, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Entity Filer Category Entity Filer Category Proceeds from sales Proceeds from Sale of Available-for-sale Securities Fair value measurements [Policy Text Block] Fair Value of Financial Instruments, Policy [Policy Text Block] Total liabilities and stockholders' equity Liabilities and Equity Entity Address, City or Town Entity Address, City or Town Number of residential real estate loans in process of foreclosure Mortgage Loans in Process of Foreclosure, Number Number of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process. Unrecognized compensation expense, RSUs provisionally granted Employee Service Share Based Compensation, Nonvested Provisional Awards, Total Compensation Cost Not Yet Recognized Share Based Awards Other Than Options Unrecognized cost of unvested provisionally granted share-based awards, other than options, awarded to employees as compensation. Other than temporary declines in investment securities Other than Temporary Impairment Losses, Investments, Available-for-sale Securities Short-term Short-term Debt With no allowance recorded, Recorded Investment Impaired Financing Receivable, with No Related Allowance, Recorded Investment Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Impaired Financing Receivables [Table Text Block] Impaired Financing Receivables [Table Text Block] Corporate [Member] Corporate Debt Securities [Member] Stockholders' Equity Stockholders' Equity Attributable to Parent [Abstract] Schedule of Comprehensive Income (Loss) [Table Text Block] Comprehensive Income (Loss) [Table Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Proceeds Proceeds from Sale of Debt Securities, Available-for-sale Fair Values and Carrying Amounts, Significant Financial Instruments [Table Text Block] Fair Value, by Balance Sheet Grouping [Table Text Block] Subsequent Events [Text Block] Subsequent Events [Text Block] With an alowance recorded, Recorded Investment Impaired Financing Receivable, with Related Allowance, Recorded Investment Financing Receivables [Text Block] Financing Receivables [Text Block] Net gains on sales of loans held for sale Net gains on sales of loans held for sale Gain (Loss) on Sales of Loans, Net Dividends [Axis] Dividends [Axis] Interest expense Interest Expense [Abstract] Award Type [Axis] Award Type [Axis] Unrecognized director compensation expense, unvested RSUs Share Based Compensation, Nonemployee Director, Nonvested Awards Total Compensation Cost Not Yet Recognized Share Based Awards Other Than Options Unrecognized cost of unvested share-based awards, other than options, awarded to nonemployee directors as compensation. 2019 Award [Member] 2019 Award [Member] 2019 grant of equity-based compensation. [Member] 2018 Award [Member] 2018 Award [Member] 2018 grant of equity-based compensation. [Member] Cash dividends declared ($0.32 and $0.31 per share for the three months ended June 30, 2020 and 2019, respectively, and $0.64 and $0.62 per share for the six months ended June 30, 2020 and 2019, respectively) Dividends, Common Stock, Cash Financing Receivable, Allowance for Credit Loss [Table Text Block] Financing Receivable, Allowance for Credit Loss [Table Text Block] Provision for loan losses Provision (credit) for loan losses Provision for Loan and Lease Losses Subsequent Events [Abstract] Subsequent Events [Abstract] Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Due from five to ten years, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Fair Value Retained earnings Retained Earnings [Member] Salaries and wages Salary and Wage, Excluding Cost of Good and Service Sold Subsequent Event [Line Items] Subsequent Event [Line Items] Liabilities Liabilities [Abstract] Document Period End Date Document Period End Date With an allowance recorded, Principal Balance Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Statement [Table] Statement [Table] Entity Registrant Name Entity Registrant Name Goodwill and Intangible Assets Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Text Block] PPP loan term Paycheck Protection Program, Loan Term Contractual term of Paycheck Protection Program loans. Consumer [Member] Consumer Portfolio Segment [Member] Net (purchases) sales of other investments Payments for (Proceeds from) Other Investments The net cash paid (received) associated with the acquisition or disposal of other investments. Cash Flows From Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Shares authorized for equity awards Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Fair Value Total debt securities available-for-sale, Fair Value Debt Securities, Available-for-sale Cash and cash equivalents Beginning of period End of period Cash and cash equivalents Cash, Cash Equivalents, and Federal Funds Sold Net decrease (increase) in nonmarketable stock Payments for (Proceeds from) Federal Home Loan Bank Stock Number of RSUs Granted Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Composition of Net Loans [Table Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Purchase of treasury stock Payments for Repurchase of Common Stock Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Consolidated Statements of Changes in Stockholders' Equity [Abstract] Consolidated Statements of Changes in Stockholders' Equity [Abstract] Consolidated Statements of Changes in Stockholders' Equity [Abstract] Entity Tax Identification Number Entity Tax Identification Number Total amount of PPP loans Paycheck Protection Program, Total Amount of Loans Outstanding Total dollar amount of loans outstanding under the SBA Paycheck Protection Program as part of the CARES Act. Net unrealized holding gains arising during the period on investment securities available-for-sale Net unrealized holding gains arising during the period on investment securities available-for-sale Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Stockholders’ Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Trading Symbol Trading Symbol Dividends paid Dividends, Cash Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Information [Line Items] Entity Information [Line Items] Maximum term for payment deferrals Financing Receivable, Modifications, Maximum Term Payment Deferral Maximum number of days for which payments will be deferred for financing receivables modified in accordance with payment deferral guidelines outlined in the CARES Act. Investment securities available-for-sale: Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent [Abstract] Comprehensive income (loss) [Policy Text Block] Comprehensive Income, Policy [Policy Text Block] Due after ten years, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value Net (increase) decrease in loans Payments for (Proceeds from) Other Loans and Leases Occupancy expense, net Occupancy, Net Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2020 Award [Member] 2020 Award [Member] 2020 grant of equity-based compensation. [Member] Legal Entity [Axis] Legal Entity [Axis] Deferred income tax provision (benefit) Deferred Income Tax Expense (Benefit) Taxable Interest Income, Securities, Operating, Taxable Adjustments to reconcile net income to net cash (used in) provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Total deposits Deposits Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Other Comprehensive Income, Tax [Abstract] Other Comprehensive Income (Loss), Tax [Abstract] Entity [Domain] Entity [Domain] Provision for income taxes Income Tax Expense (Benefit) Share-based Payment Arrangement [Text Block] Share-based Payment Arrangement [Text Block] Total reclassifications Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax With no allowance recorded, Principal Balance Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Loans Total Loans, net Loans and Leases Receivable, Gross Net unrealized holding gains arising during the period on investment securities available-for-sale, Tax Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Goodwill and Intangible Assets [Table] Goodwill and Intangible Assets [Table] Amounts related to goodwill and intangible assets disclosures [Table] Individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment City Area Code City Area Code Employee benefits Other Postretirement Benefits Cost (Reversal of Cost) Accrued interest and other liabilities Other Liabilities Title of 12(b) Security Title of 12(b) Security (Increase) decrease in accrued interest receivable Increase (Decrease) in Accrued Interest Receivable, Net Loans held for sale Loans Receivable Held-for-sale, Net, Not Part of Disposal Group Interest and fees on loans Interest and Fee Income, Loans and Leases Estimated Fair Value [Member] Estimate of Fair Value Measurement [Member] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Concentration Risk [Table] Concentration Risk [Table] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Service fees Service fees Total fees and commissions earned from providing services such as leasing of space or maintaining: (1) depositor accounts; (2) merchant program; (3) mortgage; (4) credit cards; (5) correspondent clearing; and (6) other such services and activities performed for others. Allocation of Investment in Loans by Impairment Methodology [Table Text Block] Allocation of Investment in Loans by Impairment Methodology [Table Text Block] Tabular disclosure of the total investment in loans based on impairment methodology by class of loan. [Table Text Block] Total other comprehensive income, Tax Other Comprehensive Income (Loss), Tax Number of TDR loans modified within the previous twelve months that had subsequently defaulted Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Award Date [Axis] Award Date [Axis] Assets Assets [Abstract] Gross losses Available-for-sale Securities, Gross Realized Losses 12 Months and over, Number of Securities Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year Purchases Payments to Acquire Available-for-sale Securities Interest on debt securities: Interest and Dividend Income, Securities, by Taxable Status [Abstract] Dividend Declared [Member] Dividend Declared [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] New TDRs, Post-Modification Outstanding Recorded Investment Financing Receivable, Troubled Debt Restructuring, Postmodification Net gain on other investments Increase (Decrease) in Equity Securities, FV-NI Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Cash Flows From Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Total noninterest expenses Noninterest Expense Due from five to ten years, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Amortized Cost Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Net gain on other investments Equity Securities, FV-NI, Unrealized Gain (Loss) Measurement Basis [Axis] Measurement Basis [Axis] Due in one year or less, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost Supplemental Schedule of Noncash Investing Activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Loans and Leases Receivable Disclosure [Abstract] Loans and Leases Receivable Disclosure [Abstract] Total Net core deposit intangible Finite-Lived Intangible Assets, Net Proceeds from sales of loans held for sale Proceeds from Sale of Loans Held-for-sale Interest on federal funds sold and overnight deposits Interest Income, Federal Funds Sold Supplemental Disclosures of Cash Flow Information Supplemental Cash Flow Information [Abstract] Comprehensive Income (Loss) Note [Text Block] Comprehensive Income (Loss) Note [Text Block] Intrinsic value of stock options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Financing Receivable, Past Due [Table Text Block] Financing Receivable, Past Due [Table Text Block] Basis of financial statement presentation [Policy Text Block] Basis of Accounting, Policy [Policy Text Block] RSUs granted to non-employee directors Share Based Compensation, Nonemployee Director, Restricted Stock Award Granted During Period, Shares The number of non-option equity instruments granted to nonemployee directors. Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Income taxes paid Income Taxes Paid, Net Noninterest expenses Noninterest Expense [Abstract] Construction Real Estate [Member] Construction Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to construction. Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Investment securities available-for-sale Available-for-sale Securities Entities [Table] Entities [Table] Common stock, shares authorized Common Stock, Shares Authorized New Troubled Debt Restructurings on Financing Receivables [Table Text Block] New Troubled Debt Restructurings on Financing Receivables [Table Text Block] Tabular disclosure of financing receivables and new troubled debt restructurings during the period. Total other comprehensive income, Before Tax Amount Other Comprehensive Income (Loss), before Tax Recoveries of amounts charged off Allowance for Loan and Lease Loss, Recovery of Bad Debts Interest on interest bearing deposits in banks Interest Income, Deposits with Financial Institutions Entity Central Index Key Entity Central Index Key Number of Unvested RSUs Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Entity Emerging Growth Company Entity Emerging Growth Company Time Time Deposits Gross Unrealized Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Stock based compensation expense Share-based Payment Arrangement, Noncash Expense Purchases Payments for Interest bearing deposits in banks The cash outflow for purchases of Interest-bearing Deposits by banks in other financial institutions, for example, certificates of deposits. Total, Number of Securities Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Gross gains Available-for-sale Securities, Gross Realized Gains Financing Receivable, Troubled Debt Restructuring [Table Text Block] Financing Receivable, Troubled Debt Restructuring [Table Text Block] Significant Other Observable Inputs (Level 2) [Member] Fair Value, Inputs, Level 2 [Member] Interest bearing deposits in banks Investment in interest bearing deposits in banks Investment in interest bearing deposits in banks (such as certificates of deposit) with varying maturity dates. New Accounting Pronouncements and Changes in Accounting Principles [Text Block] New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Record date, cash dividend Dividends Payable, Date of Record Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Allowance for Credit Losses [Text Block] Allowance for Credit Losses [Text Block] Schedule of Realized Gain (Loss) [Table Text Block] Schedule of Realized Gain (Loss) [Table Text Block] Municipal [Member] Municipal Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to municipalities. Agency mortgage-backed [Member] US Government Agencies Debt Securities [Member] Origination of loans held for sale Payments for Origination and Purchases of Loans Held-for-sale Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Stock based compensation expense, shares Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Net unrealized gain on investment securities available-for-sale AOCI, Debt Securities, Available-for-sale, Adjustment, after Tax Total origination fees on PPP loans Paycheck Protection Program, Origination Fee Origination fee to be collected related to loans outstanding under the SBA Paycheck Protection Program as part of the CARES Act. Tax exempt Interest Income, Securities, Operating, Tax Exempt 30 - 59 Days [Member] Financial Asset, 30 to 59 Days Past Due [Member] Investment securities pledged as collateral Pledged Financial Instruments, Not Separately Reported, Securities Total other comprehensive income, Net of Tax Amount Other Comprehensive Income (Loss), Net of Tax Cash Flows From Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Long-term Long-term Debt 2020 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year Investment securities available-for-sale Investment securities available-for-sale [Abstract] Payments for (proceeds from) investment securities available-for-sale [Abstract] Total, Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Purchases of premises and equipment Payments to Acquire Property, Plant, and Equipment Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Award Date [Domain] Award Date [Domain] 12 Months and over, Gross Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Equity in losses of limited partnerships Amortization Method Qualified Affordable Housing Project Investments, Amortization Share-based Compensation Arrangements by Share-based Payment Award, Restricted Stock Units, Vested and Expected to Vest [Table Text Block] Share-based Compensation Arrangements by Share-based Payment Award, Restricted Stock Units, Vested and Expected to Vest [Table Text Block] Due after ten years, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost Short-term, Fair Value Short-term Debt, Fair Value Accrued interest receivable Interest Receivable Loans, Past Due Financing Receivable, Past Due Net decrease (increase) in unamortized loan costs Increase (Decrease) in Loans, Deferred Income Net deferred loan (fees) costs Loans and Leases Receivable, Deferred Income Related Allowance Impaired Financing Receivable, Related Allowance Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Agency mortgage-backed, Amortized Cost Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost Subsequent Event [Table] Subsequent Event [Table] Accounting Policies [Abstract] Accounting Policies [Abstract] Additional paid-in capital Additional Paid-in Capital [Member] Commercial [Member] Commercial Portfolio Segment [Member] Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Exercise of stock options, shares Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture Consolidated Statements of Cash Flows [Abstract] Consolidated Statements of Cash Flows [Abstract] Consolidated Statements of Cash Flows [Abstract] Less than 12 Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Fair Value Measurement [Domain] Fair Value Measurement [Domain] Commercial Real Estate [Member] Commercial Real Estate Portfolio Segment [Member] Entity Address, Address Line One Entity Address, Address Line One 2008 ISO Plan [Member] 2008 ISO Plan [Member] 2008 Incentive Stock Option Plan of the Company [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Loans, net, Fair Value Loans Receivable, Fair Value Disclosure Entity Address, State or Province Entity Address, State or Province Debt securities with single maturity date, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Nonmarketable equity securities Nonmarketable equity securities Securities that do not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Example is Federal Home Loan Bank (FHLB) stock that represents an equity interest in a FHLB. Investments Classified by Contractual Maturity Date [Table Text Block] Investments Classified by Contractual Maturity Date [Table Text Block] Loans, Current Financing Receivable, Not Past Due Investment in limited partnerships acquired by capital contributions payable Increase in capital contributions payable for limited partnership investments The net change in capital contributions payable for investment in limited partnerships. Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Investing Activities Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Interest on deposits Interest Expense, Deposits Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Significant Accounting Policies [Text Block] Significant Accounting Policies [Text Block] Total, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Entity Interactive Data Current Entity Interactive Data Current Total, Gross Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Common stock, shares issued Common Stock, Shares, Issued Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Common stock, par value Common Stock, Par or Stated Value Per Share Federal funds sold and overnight deposits Federal Funds Sold Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Cash and due from banks Cash and Due from Banks Company-owned life insurance Bank Owned Life Insurance Amounts charged off Allowance for Loan and Lease Losses, Write-offs Earnings Per Share [Text Block] Earnings Per Share [Text Block] New TDRs, Number of Loans Financing Receivable, New Modifications, Number of Contracts Number of financing receivables that have been modified by troubled debt restructurings during the reporting period. Net increase (decrease) in noninterest bearing deposits Net Change Noninterest-bearing Deposits Net Change in Noninterest-bearing Deposits, domestic and foreign Stock based compensation expense Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture Award Type [Domain] Award Type [Domain] Loans, Nonaccrual Financing Receivable, Nonaccrual Number of loans receiving payment deferrals Financing Receivable, Modifications, Number of Payment Deferrals Number of loans for which payments were deferred for financing receivables modified in accordance with payment deferral guidelines outlined in the CARES Act. Interest bearing deposits in banks Net change in Interest bearing deposits in banks [Abstract] The net cash inflow or outflow in Interest-bearing Deposits by banks in other financial institutions including, for example, certificates of deposits. 60 - 89 Days [Member] Financial Asset, 60 to 89 Days Past Due [Member] Gross Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Increase in other assets Increase (Decrease) in Other Operating Assets RSUs provisionally granted Stock Provisionally Granted During Period, Shares, Restricted Stock Award Number of non-option equity instruments provisionally granted to participants. Satisfactory/Monitor [Member] Satisfactory and Monitor [Member] A category of financing receivables considered to have potential credit weaknesses that are currently marginally acceptable with no loss of principal or interest envisioned. [Member] Dividends paid Payments of Ordinary Dividends, Common Stock Restricted Stock Units (RSUs) [Member] Restricted Stock Units (RSUs) [Member] State and political subdivisions [Member] US States and Political Subdivisions Debt Securities [Member] Intangible assets [Policy Text Block] Goodwill and Intangible Assets, Policy [Policy Text Block] Consolidated Statements of Comprehensive Income [Abstract] Consolidated Statements of Comprehensive Income [Abstract] Consolidated Statements of Comprehensive Income [Abstract] US Government-sponsored enterprises [Member] US Government-sponsored Enterprises Debt Securities [Member] Long-term, Fair Value Long-term Debt, Fair Value 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] Aggregate interest on nonaccrual loans not recognized Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans Total liabilities Liabilities Common stock, $2.00 par value; 7,500,000 shares authorized; 4,950,430 shares issued at June 30, 2020 and 4,948,245 shares issued at December 31, 2019 Common Stock, Value, Issued Proceeds from maturities, calls and paydowns Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Agency mortgage-backed, Fair Value Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value [Abstract] Residential Real Estate [Member] Residential Portfolio Segment [Member] Noninterest income Noninterest Income [Abstract] Borrowed funds Debt and Lease Obligation Weighted average number of common shares outstanding Weighted Average Number of Shares Outstanding, Basic Loans [Policy Text Block] Financing Receivable, Held-for-investment [Policy Text Block] Equity Components [Axis] Equity Components [Axis] Total, Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Total stockholders' equity Balances Balances Stockholders' Equity Attributable to Parent Amortization of core deposit intangible Amortization of Intangible Assets Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Increase in other liabilities Increase (Decrease) in Other Operating Liabilities Dividends paid on Common Stock: Dividends, Common Stock [Abstract] Interest and dividend income Interest and Dividend Income, Operating [Abstract] Schedule of Unrealized Loss on Investments [Table Text Block] Schedule of Unrealized Loss on Investments [Table Text Block] Net amortization of premiums on investment securities Accretion (Amortization) of Discounts and Premiums, Investments Exercise of stock options Shares Issued, Value, Share-based Payment Arrangement, before Forfeiture Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract] Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract] Fair Value Disclosures [Text Block] Fair Value Disclosures [Text Block] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Interest bearing Interest-bearing Non-time Deposits Interest-bearing Non-time Deposits Recorded investment in residential real estate loans in process of foreclosure Mortgage Loans in Process of Foreclosure, Amount Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Core deposit intangible at acquisition Finite-Lived Intangible Assets, Gross Interest Paid Interest Paid, Excluding Capitalized Interest, Operating Activities Total interest and dividend income Interest and Dividend Income, Operating Purchase of treasury stock Treasury Stock, Value, Acquired, Cost Method Security Exchange Name Security Exchange Name 90 Days and Over and Accruing [Member] Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Investments in limited partnerships Payments to Acquire Limited Partnership Interests Net cash (used in) provided by operating activities Net Cash Provided by (Used in) Operating Activities Equity Component [Domain] Equity Component [Domain] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] 2021 Provisional Award [Member] 2021 Provisional Award [Member] 2021 provisional grant of equity-based compensation. [Member] Document Transition Report Document Transition Report Net interest income Interest Income (Expense), Net Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Net loans Net loans Loans and Leases Receivable, Net Amount PPP loans pledged as collateral Paycheck Protection Program Loans Pledged as Collateral Paycheck Protection Program Loans pledged as collateral for borrowings under the Paycheck Protection Program Liquidity Facility of the FRB. Dividend reinvestment plan Dividends reinvested Stock Issued During Period, Value, Dividend Reinvestment Plan Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Troubled Debt Restructuring [Line Items] Declaration date, cash dividend Dividends Payable, Date Declared Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Income Statement [Abstract] Income Statement [Abstract] Goodwill at acquisition Goodwill, Gross