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For interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date. 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Single Family Non-owner Occupied [Member] Information pertaining to single family non-owner occupied loans. Financial Instruments [Domain] Non-farm, Non-residential [Member] Information pertaining to non-farm, non-residential loans. Commercial and Industrial [Member] Information pertaining to commercial and industrial loans. Multi-family Residential [Member] Information pertaining to multi-family residential loans. Farmland [Member] Information pertaining to farmland loans. Consumer Real Estate Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to consumer real estate receivables. Agricultural [Member] Information pertaining to agricultural loans. Financial Instrument [Axis] Home Equity Lines [Member] Information pertaining to home equity lines. Securities available for sale, no single maturity date, fair value Single Family Owner Occupied [Member] Information pertaining to single family owner occupied loans. Owner Occupied Construction [Member] Information pertaining to owner occupied construction. Other Loan [Member] Information pertaining to other loans. Lessee, Operating Leases [Text Block] Consumer and Other Portfolio Segment [Member] Portfolio segment of the company's total financing receivables related to consumer and other receivables. Securities available for sale, no single maturity date, amortized cost Consumer Loans [Member] Information pertaining to consumer loans. Proceeds from sale of premises and equipment Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Service fees The amount of service fees during the period. Credit Facility [Axis] Credit Facility [Domain] Allowance for Credit Losses and Recorded Investment in Loans by Segment and Class [Table Text Block] Tabular disclosure of allowance for credit losses and recorded investment in loans by segment and class. us-gaap_PolicyTextBlockAbstract Accounting Policies Special Mention [Member] Substandard [Member] Gross realized gains Doubtful [Member] fcbc_IncreaseDecreaseInAccumulatedOtherComprehensiveIncome Decrease in accumulated other comprehensive loss Represents the increase (decrease) in accumulated other comprehensive income in noncash investing or financing activities. Unlikely to be Collected Financing Receivable [Member] us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield Beginning balance Ending balance us-gaap_PaymentsToAcquireProductiveAssets Payments to acquire premises and equipment SBA CARES Act Paycheck Protection Program [Member] Information related to The Paycheck Protection Program established by the CARES Act and implemented by the Small Business Administration . us-gaap_DebtSecuritiesAvailableForSaleRealizedLoss Gross realized losses Reclassifications (to) from nonaccretable difference(1) Schedule of Information Related to Purchased Credit Impaired Loans [Table Text Block] Tabular disclosure of information related to purchased credit impaired loans. us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion Accretion Waccamaw Commercial [Member] Information pertaining to Waccamaw Commercial loans. Dilutive effect of potential common shares (in shares) Transfer of loans to other real estate owned PCI loans, unpaid principal balance Waccamaw Serviced Home Equity Lines [Member] Information pertaining to Waccamaw serviced home equity lines. Allowance for Credit Losses [Text Block] PCI loans, recorded investment Waccamaw Residential [Member] Information pertaining to Waccamaw residential loans. Peoples Commercial [Member] Information pertaining to Peoples Commercial loans. Other Commercial Loan [Member] Information pertaining to other commercial loans. TDRs Financing Receivable, Troubled Debt Restructuring Weighted average shares outstanding Allowance for acquired impaired loans Represents the amount of allowance for acquired impaired loans. FDIC Loss Share Agreement Receivable [Text Block] Entire disclosure of FDIC loss share agreement. Cash paid for income taxes Net (loss) gain on sale of securities Gain recognized Peoples Residential [Member] Information pertaining to Peoples residential loans. Acquired impaired loans evaluated for impairment Represents the amount of acquired impaired loans evaluated for impairment. Liabilities fcbc_PercentageOfLossCoveredByFDIC Percentage of Loss Covered by FDIC Represents the percentage of loss covered by the FDIC. Reimbursable expenses to the FDIC Amount of increases to the indemnification asset due to acquisitions of assets relating reimbursable expenses accrued with the Federal Deposit Insurance Corporation (FDIC). Pre-modification recorded investment Post-modification recorded investment us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 Financing Receivable, Troubled Debt Restructuring, Subsequent Default us-gaap_Assets Total assets Supplemental disclosure -- cash flow information Below Market Interest Rate and Extended Payment Term [Member] Information pertaining to below market interest rates and extended payment terms. Payment Deferral [Member] Unsecured Line of Credit [Member] Information pertaining to the unsecured line of credit. Total contracts Below Market Interest Rate [Member] Information pertaining to below market interest rates. Compensation and Employee Benefit Plans [Text Block] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Domain] fcbc_IssuanceOfCommonStockTo401kPlan Issuance of common stock to 401(k) plan Represents issuance of common stock to 401(k) plan. Retail Repurchase Agreements [Member] Information pertaining to retail repurchase agreements. Impaired Financing Receivables [Table Text Block] Financing Receivable, Troubled Debt Restructuring [Table Text Block] fcbc_FinancingReceivableDeferredPayments Financing Receivable, Deferred Payments Deferred amounts on loans receivable related to loan modification programs offered to financial institution customers affected by COVID-19. fcbc_FinancingReceivableNumberOfPaymentDeferrals Financing Receivable, Number of Payment Deferrals Number of payment deferrals on loans receivable related to loan modification programs offered to financial institution customers affected by COVID-19. fcbc_FinancingReceivableNumberClosedUnderPaycheckProtectionProgramUnderCaresAct Financing Receivable, Number Closed Under Paycheck Protection Program Under CARES Act The number of financing receivables closed under paycheck protection program under the CARES act. Total loans Loans held for investment, net of unearned income (includes covered loans of $11,257 and $12,861, respectively) Total loans held for investment, net of unearned income Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans and leases covered under loss sharing agreements. Other assets Loans Insured or Guaranteed by Government Authorities [Axis] Covered loans, percent Percent of loans and leases receivable covered by loss sharing agreements. Loans Insured or Guaranteed by Government Authorities [Domain] Schedule of Covered Loans Held for Investment Net of Unearned Income [Table Text Block] Tabular disclosure of covered loans held for investment, net of unearned income. Non-covered loans, percent Percent before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements. fcbc_LoansAndLeasesReceivableNetOfDeferredIncomeAndNetReportedAmountPercent Total loans held for investment, net of unearned income, percent Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans and leases covered under loss sharing agreements. Purchased Credit Impaired Loans [Member] Information pertaining to purchased credit impaired loans. Net income Net income Net income Peoples Bank of Virginia [Member] Information pertaining to Peoples Bank of Virginia. Other intangible assets Interest and Fees on Loans [Member] Primary financial statement caption encompassing interest and fees on loans. Waccamaw Bank [Member] Information pertaining to Waccamaw Bank. us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing Financing Receivable, 90 Days or More Past Due, Still Accruing Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Accretable Yield [Table Text Block] Tabular disclosure of certain loans acquired in transfer not accounted for as debt securities accretable yield. Financing Receivable Credit Quality Indicators [Table Text Block] Other Receivables [Member] Information pertaining to other receivables. Restricted Stock [Member] Current loans Other changes, net Amount of removals, extensions, and other events in the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality. Share-based Payment Arrangement, Option [Member] Past due Total nonaccrual loans Financial Asset, 30 to 59 Days Past Due [Member] Antidilutive Securities [Axis] Financial Asset, 60 to 89 Days Past Due [Member] Antidilutive Securities, Name [Domain] Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financing Receivable, Past Due [Table Text Block] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Domain] Deferred compensation liabilities Deferred compensation liabilities Fair value portion of deferred compensation liabilities. fcbc_PaymentsToTheFederalDepositInsuranceCorporation Payments to the FDIC The amount of cash paid to the Federal Deposit Insurance Corporation during the period. Financing Receivables [Text Block] Deferred compensation assets Deferred compensation assets Fair value portion of deferred compensation assets. Commitments and Contingencies Disclosure [Text Block] Business Combination Disclosure [Text Block] Impaired Loans [Member] Information pertaining to impaired loans. Schedule of Business Acquisitions, by Acquisition [Table Text Block] Premises and equipment, net Goodwill Goodwill us-gaap_PaymentsForProceedsFromLoansAndLeases (Originations of) proceeds from repayment of loans, net Bank Time Deposits [Member] Non-covered Loans [Member] Information pertaining to non-covered loans. FDIC premiums and assessments Amount of expense for Federal Deposit Insurance Corporation (FDIC) insurance and assessments. Covered Loans [Member] Information pertaining to covered loans. OREO [Member] Information pertaining to other real estate owned (OREO). fcbc_RestructuredLoansReserves Restructured Loans, Reserves Represents the amount of reserves for restructured loans. Reserve for unfunded commitments Represents the amount of reserve for unfunded credit commitments. Allowance for loan losses related to TDRs Represents the amount of allowance for loan losses. Derivative assets us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock (Purchase of) proceeds from FHLB stock, net Increase in other operating activities Derivative Instrument [Axis] Derivative Contract [Domain] Investing activities Available-for-sale debt securities Debt securities available for sale Securities available for sale, fair value Earnings per common share Earnings Per Share [Text Block] Equity securities us-gaap_EquitySecuritiesFvNi Discount range, impaired loans The measurement input for non-covered impaired loans. (Receipts from) payments to the FDIC The amount of cash payments received (made) on FDIC indemnification asset. OREO The measurement input for non-covered other real estate owned. Income tax expense Income tax expense Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Residential real estate loans in the foreclosure process(1) us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount Debt Instrument, Unused Borrowing Capacity, Amount Interest-bearing deposits in banks Salaries and employee benefits Cash and due from banks Schedule of Impaired Financing Receivable, Average Recorded Investment and Interest Income Recognized [Table Text Block] Tabular disclosure of impaired financing receivable related to average recorded investment and interest income recognized. Trouble Debt Restructuring Accrual Status [Table Text Block] Tabular disclosure of accrual status related to trouble debt restructuring . Loans individually evaluated for impairment Loans collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Nonaccrual Recorded investment in financing receivables that have been modified by troubled debt restructurings and are on nonaccrual status as of the balance sheet date. Troubled Debt Restructurings [Member] Information pertaining to trouble debt restructurings. Allowance for loans individually evaluated Accrual Recorded investment in financing receivables that have been modified by troubled debt restructurings and are on accrual status as of the balance sheet date. Allowance for loans collectively evaluated Interest Income Related to Troubled Debt Restructurings [Table Text Block] Tabular disclosure of interest income related to troubled debt restructurings. Amendment Flag FDIC Indemnification Asset Roll Forward [Table Text Block] us-gaap_ComprehensiveIncomeNetOfTax Total comprehensive income City Area Code Use of Estimates, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Credit Loss Status [Axis] Other Real Estate Owned [Table Text Block] Tabular disclosure of other real estate owned. Credit Loss Status [Domain] Reclassification, Comparability Adjustment [Policy Text Block] Financial Asset Acquired with Credit Deterioration [Member] us-gaap_GainLossOnSaleOfPropertyPlantEquipment Gain on sale of premises and equipment, net Common stock, outstanding (in shares) Preferred stock, outstanding (in shares) Financing Receivable, Allowance for Credit Loss [Table Text Block] OREO secured by residential real estate Represents the amount of non-covered other real estate owned secured by residential real estate. Weighted average rate us-gaap_DebtWeightedAverageInterestRate Current Fiscal Year End Date us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate us-gaap_DebtAndEquitySecuritiesRealizedGainLoss (Gain) Loss on sale of securities Recoveries Basis of Accounting [Text Block] us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent Operating Lease, Weighted Average Discount Rate, Percent us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss Net loss on sale of securities Interest receivable Document Fiscal Period Focus Document Fiscal Year Focus Consolidation, Policy [Policy Text Block] us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs Charge-offs us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet Net charge-offs Document Period End Date Entity File Number Entity Emerging Growth Company Document Type Entity Small Business Litigation settlements Entity Shell Company us-gaap_DividendsCommonStockCash Common dividends declared Document Information [Line Items] Document Information [Table] Entity Filer Category Entity Current Reporting Status us-gaap_BusinessCombinationAcquisitionRelatedCosts Business Combination, Acquisition Related Costs us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet (Increase) decrease in accrued interest receivable Federal Home Loan Bank Borrowings [Member] Statement of Comprehensive Income [Abstract] Entity Tax Identification Number Entity Central Index Key Entity Registrant Name Liability Class [Axis] Fair Value by Liability Class [Domain] Entity [Domain] Legal Entity [Axis] Entity Address, Address Line One Amortization of intangible assets Amortization of intangibles Entity Address, City or Town FDIC indemnification asset Beginning balance Ending balance Entity Address, Postal Zip Code Other real estate owned Total OREO Entity Address, State or Province OREO us-gaap_OtherRealEstateNonCovered Entity Common Stock, Shares Outstanding Depreciation and amortization of premises and equipment us-gaap_StockRepurchasedAndRetiredDuringPeriodValue Repurchase of common shares Purchase of treasury shares Repurchase of common shares, shares (in shares) Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Advertising and public relations us-gaap_LoansAndLeasesReceivableNetReportedAmountCoveredAndNotCovered Loans held for investment, net us-gaap_LoansAndLeasesReceivableGrossCarryingAmount Loans and Leases Receivable, Gross, Total Professional fees Non-covered loans Non-covered us-gaap_LoansAndLeasesReceivableAllowance Loans and Leases Receivable, Allowance, Ending Balance Allowance for loan losses Beginning balance Ending balance Amortization of prior service cost Investments [Domain] us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses Amortization of losses Trading Symbol us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost Net periodic cost us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums, Total Service cost Interest cost Occupancy expense Investment Type [Axis] Issuance of common stock to 401(k) plan Local Phone Number Issuance of stock to 401(k) plan, shares (in shares) Common stock options exercised, shares (in shares) us-gaap_TableTextBlock Notes Tables us-gaap_GainLossOnSaleOfOtherAssets Loss on sale of other real estate owned us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Common stock options exercised Covered loans Loans held for investment, covered Equity-based compensation expense us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders' equity us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1 Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged Reported Value Measurement [Member] us-gaap_CashCashEquivalentsAndFederalFundsSold Total cash and cash equivalents Other operating expense Federal funds sold Retained earnings Retained Earnings (Accumulated Deficit), Ending Balance Accumulated other comprehensive loss Measurement Input, Discount Rate [Member] Debt Disclosure [Text Block] Derivative Instruments, Gain (Loss) [Table Text Block] us-gaap_InterestExpense Total interest expense Highlands Bankshares, Inc. [Member] Represents Highlands Bankshares, Inc. us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Derivative Instruments and Hedging Activities Disclosure [Text Block] fcbc_BusinessCombinationStockConversionRatio Business Combination, Stock Conversion Ratio The stock conversion ratio for a business combination. us-gaap_OperatingLeaseLiability Operating Lease, Liability, Total Interest on short-term borrowings Fair Value Adjustments [Member] Represents the fair value adjustments. Loans held for investment, net of allowance and mark fcbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansHeldForInvestmentNetOfAllowanceAndMark The amount of loans held for investment, net of allowance and mark recognized as of the acquisition date. fcbc_DeferredLoanFeesExcludedFromFairValueAdjustmentOfAcquiredLoan Deferred Loan Fees Excluded from Fair Value Adjustment of Acquired Loan The amount of deferred loan fees that excluded from the fair value adjustment of acquired loan. us-gaap_OperatingLeaseRightOfUseAsset Operating Lease, Right-of-Use Asset fcbc_AcquiredLoanFairValueAdjustments Acquired Loan, Fair Value Adjustments The increase (decrease) to acquired loan related to the fair value adjustments. us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total lease payments us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Less: Interest Measurement Input Type [Axis] fcbc_ReserveForUnfundedCommitmentsFairValueAdjustment Reserve for Unfunded Commitments, Fair Value Adjustment The increase (decrease) to reserve for unfunded commitments related to the fair value adjustment. Measurement Input Type [Domain] fcbc_LeaseLiabilityFairValueAdjustment Lease Liability, Fair Value Adjustment The increase (decrease) to lease liability related to the fair value adjustment. fcbc_DeathBenefitsPayableFairValueAdjustment Death Benefits Payable, Fair Value Adjustment The increase (decrease) to death benefits payable related to the fair value adjustment. Interest on deposits Interest-bearing fcbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInterestBearingDeposits Amount of interest-bearing deposits assumed at the acquisition date. Noninterest-bearing fcbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoninterestBearingDeposits Amount of noninterest-bearing deposits assumed at the acquisition date. Valuation, Market Approach [Member] Other real estate fcbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherRealEstate The amount of other real estate recognized as of the acquisition date. Loans held for sale fcbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansHeldForSale The amount of loans held for sale recognized as of the acquisition date. us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour 2024 Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Recorded by Acquiree [Member] The values recorded by the acquiree. us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths 2021 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo 2022 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree 2023 Lessee, Operating Lease, Liability, Maturity [Table Text Block] us-gaap_ShareBasedCompensation Equity-based compensation expense Construction and Land Development [Member] Represents construction and land development. 1-4 family, Senior-commercial [Member] Represents the 1-4 family, senior-commercial. Interest expense: Multifamily [Member] Represents multifamily. Farmland and Other Agricultural [Member] Represents farmland and other agricultural. 1-4 Family, Senior-consumer [Member] Represents 1-4 family, senior-consumer. 1-4 Family, Junior and HELOCS [Member] Represents 1-4 family, junior and HELOCS. Total Fair Value us-gaap_InterestAndDividendIncomeOperating Total interest income us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments Amortization of premiums on investments, net Highlands [Member] Represents loans acquired from Highlands. Interest on deposits in banks Purchase price per share of the Company's common stock (in dollars per share) us-gaap_SharesIssuedPricePerShare us-gaap_LoansHeldForSaleFairValueDisclosure Loans held for sale Cash and cash equivalents us-gaap_SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure Securities sold under agreements to repurchase Interest on securities -- taxable Interest on securities -- tax-exempt Fair Value, Nonrecurring [Member] Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Common stock, $1 par value; 50,000,000 shares authorized; 24,306,138 shares issued and 17,709,569 outstanding at June 30, 2020; 24,238,907 shares issued and 18,376,991 outstanding at December 31, 2019 us-gaap_AmortizationOfDeferredLoanOriginationFeesNet Amortization of Deferred Loan Origination Fees, Net Adjustments to reconcile net income to net cash provided by operating activities Measurement Frequency [Axis] Interest and fees on loans Measurement Frequency [Domain] us-gaap_DepositLiabilitiesCollateralIssuedFinancialInstruments Deposit Liabilities, Collateral Issued, Financial Instruments Fair Value, Recurring [Member] Common stock, authorized (in shares) Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Common stock, issued (in shares) Common stock, par value (in dollars per share) Statistical Measurement [Domain] Maximum [Member] Minimum [Member] Weighted Average [Member] Product and Service [Axis] Product and Service [Domain] Statistical Measurement [Axis] Interest income: Preferred stock, undesignated par value; 1,000,000 shares authorized; Series A Noncumulative Convertible Preferred Stock, $0.01 par value; 25,000 shares authorized; none outstanding Individual retirement accounts Cash paid for interest Preferred stock, no par value (in dollars per share) Money market accounts Savings deposits Preferred stock, authorized (in shares) Certificates of deposit Interest-bearing demand deposits Portion at Fair Value Measurement [Member] [Default] Preferred stock, par value (in dollars per share) Estimate of Fair Value Measurement [Member] Other operating income Total noninterest income Noninterest income Measurement Basis [Axis] Fair Value, Inputs, Level 3 [Member] Fair Value Hierarchy and NAV [Domain] Deposit Liabilities Disclosures [Text Block] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Noninterest income: Fair Value Hierarchy and NAV [Axis] Provision for loan losses Provision for credit losses us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss Net interest income after provision for loan losses Provision for (recovery of) loan losses charged to operations Provision for Loan and Lease Losses, Total Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption, Adjustment [Member] us-gaap_InterestIncomeExpenseNet Net interest income Operating activities Statement [Line Items] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] us-gaap_NumberOfOperatingSegments Number of Operating Segments Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Additional paid-in capital AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] us-gaap_FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability Total off-balance sheet risk AOCI Attributable to Parent [Member] Stockholders' equity Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block] Fair value loans us-gaap_LoansReceivableFairValueDisclosure Loans held for investment, net of allowance Deposit Account [Member] Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Table Text Block] Fair Value, by Balance Sheet Grouping [Table Text Block] us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Assets us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net increase in cash and cash equivalents us-gaap_Liabilities Total liabilities us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash provided by (used in) financing activities us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash provided by investing activities fcbc_DeferredLoanFees Deferred Loan Fees Represents deferred loan fees. Derivative liabilities Derivative liabilities Interest payable fcbc_PerformingStatusReturnedPeriod Performing Status Returned Period (Month) Represents the performing status return period. 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Net actuarial (loss) gain Employee benefit plans: Mortgage-backed Agency Securities [Member] Information pertaining to mortgage-backed agency securities. 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