Measurement Basis [Axis] Carrying Amount [Member] Fair Value [Member] Fair Value, Hierarchy [Axis] Quoted Prices in Active Markets for Identical Assets (Level I) [Member] Significant Other Observable Inputs (Level II) [Member] Significant Unobservable Inputs (Level III) [Member] Financial Instrument [Axis] U.S. Government Agencies [Member] U.S. Agency Mortgage-Backed Securities [Member] U.S. Agency Collateralized Mortgage Obligations [Member] Corporate Bonds [Member] Obligations of States and Political Subdivisions [Member] Total Debt Securities [Member] Equity Securities [Member] Measurement Frequency [Axis] Fair Value Measured on a Recurring Basis [Member] Financing Receivable Portfolio Segment [Axis] Commercial Real Estate [Member] Consumer Real Estate [Member] Commercial and Industrial [Member] Consumer Portfolio Segment [Member] Commercial and Industrial Sector [Member] Unallocated [Member] Equity Components [Axis] Unrealized Gains (Losses) on Securities Available-for-Sale [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Member] Class of Financing Receivable [Axis] Construction [Member] Fair Value Measured on a Nonrecurring Basis [Member] Asset Class [Axis] Impaired Loans [Member] Range [Axis] Weighted Average [Member] Loans Serviced for Others [Member] CRA Investment Fund [Member] Regulatory Bank Stock [Member] Loan Commitments [Member] Line of Credit [Member] Letter of Credit [Member] 1-4 Family Residential Mortgages [Member] Home Equity Loan [Member] Home Equity Lines of Credit [Member] Class of Financing Receivable, Type of Borrower [Axis] Consumer Borrower [Member] Financial Instrument Performance Status [Axis] Performing [Member] Nonperforming [Member] Industry Sector [Axis] Agricultural Sector [Member] Tax-free loans [Member] Agriculture loans [Member] Internal Credit Assessment [Axis] Pass [Member] Special Mention [Member] Substandard [Member] Doubtful [Member] Loss [Member] Financing Receivables, Period Past Due [Axis] Greater than 90 Days Past Due [Member] 60-89 Days Past Due [Member] 30-59 Days Past Due [Member] Mortgages [Member] Collateral [Axis] Commercial real estate [Member] Consumer real estate [Member] Home equity lines of credit [Member] Agriculture loans [Member] Total Commercial and Industrial Sector [Member] Investment Type [Axis] Bank stocks [Member] CRA-qualified mutual funds [Member] Asset-backed Securities [Member] Document And Entity Information Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Current Fiscal Year End Date Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Common Stock, Shares Outstanding Document Fiscal Period Focus Document Fiscal Year Focus Statement of Financial Position [Abstract] ASSETS Cash and due from banks Interest-bearing deposits in other banks Total cash and cash equivalents Securities available for sale (at fair value) Equity securities (at fair value) Loans held for sale Loans (net of unearned income) Less: Allowance for loan losses Net loans Premises and equipment Regulatory stock Bank owned life insurance Other assets Total assets LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities: Deposits: Noninterest-bearing Interest-bearing Total deposits Short-term borrowings Long-term debt Other liabilities Total liabilities Stockholders' equity: Common stock, par value $0.20; Shares: Authorized 12,000,000 Issued 2,869,557 and Outstanding 2,861,274 as of 9/30/18 Issued 2,869,557 and Outstanding 2,849,823 as of 12/31/17 Issued 2,869,557 and Outstanding 2,848,679 as of 9/30/17 Capital surplus Retained earnings Accumulated other comprehensive loss net of tax Less: Treasury stock cost on 8,283 shares as of 9/30/18 19,734 shares as of 12/31/17 and 20,878 shares as of 9/30/17 Total stockholders' equity Total liabilities and stockholders' equity Common stock, par value Common stock, authorized Common stock, issued Common stock, outstanding Treasury shares Income Statement [Abstract] Interest and dividend income: Interest and fees on loans Interest on securities available for sale Taxable Tax-exempt Interest on deposits at other banks Dividend income Total interest and dividend income Interest expense: Interest on deposits Interest on borrowings Total interest expense Net interest income Provision for loan losses Net interest income after provision for loan losses Other income: Trust and investment services income Service fees Commissions Gains (losses) on the sale of debt securities, net Gains on equity securities, net Gains on sale of mortgages Earnings on bank-owned life insurance Other income Total other income Operating expenses: Salaries and employee benefits Occupancy Equipment Advertising & marketing Computer software & data processing Shares tax Professional services Other expense Total operating expenses Income before income taxes Provision for federal income taxes Net income Earnings per share of common stock Cash dividends paid per share Weighted average shares outstanding Statement of Comprehensive Income [Abstract] Net income Other comprehensive income (loss), net of tax: Securities available for sale not other-than-temporarily impaired: Unrealized gains (losses) arising during the period Income tax effect Total Gain/(loss) on sale of debt securities recognized in earnings Income tax effect Total Other comprehensive income (loss), net of tax Comprehensive Income Net change in unrealized gains: Other-than-temporarily impaired securities available for sale: Gains arising during the period Income tax effect Total Losses recognized in earnings Income tax effect Total Unrealized holding gains on other-than-temporarily impaired securities available for sale, net of tax Statement of Cash Flows [Abstract] Cash flows from operating activities: Adjustments to reconcile net income to net cash provided by operating activities: Net amortization of securities premiums and discounts and loan fees Decrease (increase) in interest receivable Increase in interest payable (Gain) loss on sale of debt securities, net Gain on equity securities, net Gain on sale of mortgages Loans originated for sale Proceeds from sales of loans Earnings on bank-owned life insurance Depreciation of premises and equipment and amortization of software Deferred income tax Other assets and other liabilities, net Net cash provided by operating activities Cash flows from investing activities: Securities available for sale: Proceeds from maturities, calls, and repayments Proceeds from sales Purchases Proceeds from the sale of equity securities Purchase of regulatory bank stock Redemptions of regulatory bank stock Purchase of bank-owned life insurance Net increase in loans Purchases of premises and equipment, net Purchase of computer software Net cash used for investing activities Cash flows from financing activities: Net increase in demand, NOW, and savings accounts Net decrease in time deposits Net increase (decrease) in short-term borrowings Proceeds from long-term debt Repayments of long-term debt Dividends paid Proceeds from sale of treasury stock Treasury stock purchased Net cash provided by financing activities Decrease in cash and cash equivalents Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Supplemental disclosures of cash flow information: Interest paid Income taxes paid Supplemental disclosure of non-cash investing and financing activities: Fair value adjustments for securities available for sale Accounting Policies [Abstract] Summary of Significant Accounting Policies Investments, Debt and Equity Securities [Abstract] Securities Available for Sale Marketable Securities [Abstract] Equity Securities Receivables [Abstract] Loans and Allowance for Loan Losses Fair Value Disclosures [Abstract] Fair Value Presentation FINANCIAL INSTRUMENTS NOT REQUIRED TO BE MEASURED OR REPORTED AT FAIR VALUE Commitments and Contingencies Disclosure [Abstract] Commitments and Contingent Liabilities Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Loss New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Recently Issued Accounting Standards Basis of Presentation Revenue from Contracts with Customers Financial Instruments Nonrefundable Fees and Other Costs Reporting Comprehensive Income Schedule of amortized cost and fair value of securities Schedule of contractual maturity of debt securities Schedule of proceeds and gains and losses on securities available for sale Schedule of securities in an unrealized loss position (temporary impairment) Schedule of security impairment charges Schedule of credit losses recognized in earnings on debt securities Schedule of Amortized Cost, Gross Unrealized gains, Losses, and Fair Value of Equity Securities Schedule of Unrealized Gains and Losses Schedule of loan portfolio by category Schedule of commercial and consumer credit exposure Schedule of aging of loans receivable Schedule of nonaccrual loans by class Schedule of impaired loans Schedule of allowance for credit losses Schedule of assets measured on a recurring basis Schedule of assets measured on a nonrecurring basis Schedule of Level III inputs Schedule of carrying amount and fair value of financial instruments Schedule of accumulated other comprehensive Cumulative effect adjustment from accumulated other comprehensive income to retained earnings Available for sale debt securities pledged or restricted for public funds, par value Available for sale debt securities pledged or restricted for public funds, fair value Number of securities considered temporarily impaired Schedule of Available-for-sale Securities [Table] Debt Securities, Available-for-sale [Line Items] Securities Available For Sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Contractual maturity of debt securities, Amortized Cost Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total debt securities Contractual maturity of debt securities, Fair Value Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Securities available for sale Gross realized gains Gross realized losses Securities in a continuous loss position Fair Value Less than 12 months More than 12 months Total Gross Unrealized Losses Less than 12 months More than 12 months Total Investment Income [Table] Net Investment Income [Line Items] Net gains (losses) recognized in equity securities during the period Less: Net gains realized on the sale of equity securities during the period Unrealized gains (losses) recognized in equity securities held at reporting date Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts, Notes, Loans and Financing Receivable [Line Items] Real estate loans serviced for others Foregone interest income for impaired loans TDRs loan Decrease in ending balance of allowance for loan losses Classified loans Increase decrease in loans Delinquency rate Decrease in ending balance of allowance for loan losses Period of historical loss rate Provision (credit) for loan losses Additional provision for loan losses Recoveries of loan losses Charge-offs Charge-off rate Class of Financing Receivable, Type [Axis] Loan Portfolio Gross loans prior to deferred fees Less: Deferred loan costs, net Allowance for loan losses Total net loans Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Statement [Line Items] Commercial [Member] Agricultural Mortgage Loans [Member] Total Schedule of Financing Receivables Past Due [Table] Financing Receivable, Recorded Investment, Past Due [Line Items] Consumer Real Estate [Member] Total Past Due Current Total Loans Receivable Loans Receivable - Greater than 90 Days and Accruing Non-accrual Loans Total impaired loans Average recorded balance of impaired loans Interest income recognized on impaired loans Schedule of Impaired Financing Receivable [Table] Financing Receivable, Impaired [Line Items] Impaired Loan Analysis Loans with no related allowance recorded: Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Loans with an allowance recorded: Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Schedule of Financing Receivable, Allowance for Credit Losses [Table] Financing Receivable, Allowance for Credit Losses [Line Items] Beginning balance Charge-offs Recoveries Provision Ending balance Allowance for credit losses: Ending balance Individually evaluated for impairment Collectively evaluated for impairment Loans receivable: Individually evaluated for impairment Collectively evaluated for impairment Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Marketable equity securities, book value Marketable equity securities, market value Impaired Financing Receivable, Recorded Investment Fair value of impaired loans Related Allowance Fair Value Hierarchy and NAV [Axis] Recurring Fair Value Measurements Securities available for sale (at fair value) Non-Recurring Fair Value Measurements Impaired Loans OREO Mortgage Servicing Assets Total Fair Value, non-recurring Valuation Techniques Unobservable inputs - Appraisal adjustments Unobservable inputs - Liquidation expenses Fair Value, by Balance Sheet Grouping [Table] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Assets: Cash and cash equivalents Securities available for sale Loans held for sale Loans, net of allowance Accrued interest receivable Financial Liabilities: Demand deposits Interest-bearing demand deposits NOW accounts Money market deposit accounts Savings accounts Time deposits Accrued interest payable Statement [Table] Commitment to extend credit Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Line Items] Beginning balance Other comprehensive loss before reclassifications Amount reclassified from accumulated other comprehensive loss Reclassification of certain income tax effects from accumulated other comprehensive income (loss) Period change Ending balance Federal income tax rate Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Gains on securities transactions, net Impairment on securities Provision for federal income taxes Reclassifications for the period Agriculture loans [Member] Agriculture loans [Member] Percentage increase (decrease) in the allowance for doubtful accounts. Total Commercial and Industrial Sector [Member] Consumer real estate [Member] CRA Investment Fund [Member] Amount, after accumulated amortization, of debt issuance costs or credit. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. Appraisal adjustments, used as an input to measure fair value. Liquidation expenses, used as an input to measure fair value. The fair value of impaired loans. Home equity lines of credit [Member] Amount of allowance for credit losses related to impaired loans recorded investment. Amount of allowance for credit losses with no related to recorded investment. The fair value disclosure for impaired loans. Impaired Loans Member The net cash inflow or outflow in the total of all demand deposits, including checking and negotiable order of withdrawal (NOW) accounts and total of all savings account deposits, which may include passbook, statement savings accounts and money-market deposit accounts (MMDAs). Amount of operating interest income (expense), including amortization and accretion of premiums and discounts, on securities subject to state, federal and other income tax. Charge-off rate. Mortgage servicing assets. Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities other-than-temporarily impaired. Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities other-than-temporarily impaired. Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities other-than-temporarily impaired. OtherComprehensiveIncomeOtherThanTemporarilyImpairedAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent Amount before tax, of unrealized holding gain (loss) on available-for-sale securities not other-than-temporarily impaired. Amount after tax, of unrealized holding gain (loss) on available-for-sale securities not other-than-temporarily impaired. Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities not other-than-temporarily impaired. Amount before tax, of unrealized holding gain (loss) on available-for-sale securities other-than-temporarily impaired. Amount after tax, of unrealized holding gain (loss) on available-for-sale securities other-than-temporarily impaired. Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities other-than-temporarily impaired. Represents the period of historical loss rate continues to decline in business mortgage pool. Amount of expense (credit) related to estimated loss from loan and lease transactions. Period change in comprehensive income. Regulatory Bank Stock [Member] 1-4 Family Residential Mortgages [Member] Income from fees assessed on deposit accounts and other various bank-related fees. Tax-free loans [Member] Trust and investment services income. Fee and commission income. Fair value of assets measured on a non-recurring basis. Description of the fair value valuation technique. Bank stocks [Member] CRA-qualified mutual funds [Member] The balance of classified loans. Tabular disclosure of nonrefundable fees and other costs. Recoveries of loan losses. Agriculture loans [Member] [Default Label] Assets Deposits Liabilities Treasury Stock, Value Stockholders' Equity Attributable to Parent Liabilities and Equity Interest and Dividend Income, Operating Interest Expense Interest Income (Expense), Net Interest Income (Expense), after Provision for Loan Loss Noninterest Income Operating Expenses Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Other Comprehensive Income Unrealized Holding Gain Loss On Securities Not Other Than Temporarily Impaired Arising During Period Tax Other Comprehensive Income Unrealized Holding Gain Loss On Securities Not Other Than Temporarily Impaired Arising During Period Net of Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent Other Comprehensive Income Unrealized Holding Gain (Loss) on Securities Other Than Temporarily Impaired Arising During Period, Tax Other Comprehensive Income (Loss) Reclassification Adjustment from AOCI for Sale of Securities Other Than Temporarily Impaired, BeforeTax Other Comprehensive Income Loss Reclassification Adjustment From AOCI For Sale of Securities Other Than Temporarily Impaired Tax Other Comprehensive Income Loss Reclassification Adjustment From AOCI For Sale of Securities Other Than Temporarily Impaired Net of Tax Accretion (Amortization) of Discounts and Premiums, Investments Increase (Decrease) in Accrued Interest Receivable, Net Payments for Origination and Purchases of Loans Held-for-sale Increase (Decrease) in Other Operating Assets and Liabilities, Net Net Cash Provided by (Used in) Operating Activities Payments to Acquire Available-for-sale Securities Payments to Acquire Federal Home Loan Bank Stock Payments for (Proceeds from) Other Investing Activities Payments for (Proceeds from) Loans and Leases Payments to Acquire Property, Plant, and Equipment Payments to Acquire Software Net Cash Provided by (Used in) Investing Activities Repayments of Long-term Debt Payments of Ordinary Dividends, Common Stock Payments for Repurchase of Common Stock Net Cash Provided by (Used in) Financing Activities Cash and Cash Equivalents, Period Increase (Decrease) Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Debt Securities, Available-for-sale, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Allowance for Doubtful Accounts Receivable, Period Increase (Decrease) Unrealized holding gains on other-than-temporarily impaired securities available for sale, net of tax [Default Label] Financing Receivable, Net Impaired Financing Receivable, with No Related Allowance, Recorded Investment Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Net increase in demand, NOW, and savings accounts [Default Label] Impaired Financing Receivable, with Related Allowance, Recorded Investment Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Impaired Financing Receivable, Unpaid Principal Balance Impairment losses on securities: Provision for or Credit from Loan and Lease Losses Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Financing Receivable, Individually Evaluated for Impairment Financing Receivable, Collectively Evaluated for Impairment Loans Held-for-sale, Fair Value Disclosure Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net