Document And Entity Information
Due after ten years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
Note To Financial Statement Details Textual
Notional amount
Significant Accounting Policies
Note 3 - Accumulated Other Comprehensive Income
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
Due in one year or less
Note 4 - Investment Securities
us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent
Unrealized gain (loss), net of tax
Note 5 - Loans and Leases
Due in one year or less
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
Note 6 - Earnings Per Share
Due after one year through five years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
Note 7 - Stock Plans
Due after five years through ten years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
Note 8 - Fair Value Measurements
Note 11 - Leases
Note 12 - Derivative Instruments
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Note 3 - Accumulated Other Comprehensive Income - Components of Accumulated Other Comprehensive Income (Details)
Note 3 - Accumulated Other Comprehensive Income - Amount Reclassified from Accumulated Other Comprehensive Income (Details)
Note 4 - Investment Securities - Summary of Amortized Cost and Fair Value of Investment Securities (Details)
Note 4 - Investment Securities - Summary of Amortized Cost and Fair Value by Contractual Maturity (Details)
Note 4 - Investment Securities - Continuous Unrealized Loss Position (Details)
Note 5 - Loans and Leases - Classifications of Loans and Leases (Details)
Note 5 - Loans and Leases - Unamortized Nets Costs and Premiums Included in Loans (Details)
Note 5 - Loans and Leases - Non-accrual Loans (Details)
Note 5 - Loans and Leases - Troubled Debt Restructurings (Details)
Note 5 - Loans and Leases - Past Due Loans (Details)
Note 5 - Loans and Leases - Impaired Loans (Details)
Outstanding, weighted average remaining contractual term (Year)
Home Equity Line of Credit [Member]
Note 5 - Loans and Leases - Credit Risk Profile (Details)
Note 5 - Loans and Leases - Collateral Dependent Loans (Details)
US States and Political Subdivisions Debt Securities [Member]
Note 5 - Loans and Leases - Change in Allowance (Details)
Note 5 - Loans and Leases - Credit Loss on Unfunded Commitments (Details)
Automobile Loan [Member]
Note 5 - Loans and Leases - Undiscounted Cash Flows for Direct Finance Leases (Details)
Share-Based Payment Arrangement, Nonvested Award, Cost [Table Text Block]
Note 6 - Earnings Per Share - Computation of Basic and Diluted EPS (Details)
Share-Based Payment Arrangement, Stock Appreciation Right, Activity [Table Text Block]
Loans held-for-sale (fair value $160 in 2023; $1,660 in 2022)
Note 7 - Stock Plans - Summary of Weighted Average Fair Value and Vesting of Restricted Stock Grants (Details)
Note 7 - Stock Plans - Non-vested Restricted Stock (Details)
Note 7 - Stock Plans - Summary of SSARs (Details)
Note 7 - Stock Plans - Stock-based Compensation Expense (Details)
Shares granted, weighted average grant date fair value (in dollars per share)
Granted, weighted average grant date fair value (in dollars per share)
Pass [Member]
Note 7 - Stock Plans - Unrecognized Stock-based Compensation Expense (Details)
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Unrealized loss position, unrealized losses, more than 12 months
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Vested, weighted average grant date fair value (in dollars per share)
us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Unrealized loss position, unrealized losses
Note 8 - Fair Value Measurements - Carrying Amount and Estimated Fair Value (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
Forfeited, weighted average grant date fair value (in dollars per share)
Note 8 - Fair Value Measurements - Fair Value on a Recurring Basis (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Outstanding, weighted average grant date fair value (in dollars per share)
Outstanding, weighted average grant date fair value (in dollars per share)
Note 8 - Fair Value Measurements - Fair Value on a Nonrecurring Basis (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Forfeited (in shares)
Note 11 - Leases - Analysis of Leased Property Under Finance Leases (Details)
Note 11 - Leases - Schedule of Future Minimum Lease Payments Under Finance Leases (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Non-vested balance (in shares)
Non-vested balance (in shares)
Note 11 - Leases - Lease Cost (Details)
Note 11 - Leases - Future Minimum Payments for Operating Leases (Details)
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Unrealized loss position, unrealized losses, less than 12 months
Schedule of Derivative Instruments [Table Text Block]
Note 11 - Leases - Undiscounted Cash Flows to be Received Under Operating Leases (Details)
Proceeds from sales
US Government Agencies Debt Securities [Member]
Internal Credit Assessment [Axis]
Note 11 - Leases - Lease Income Recognized (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Granted (in shares)
Proceeds from maturities, calls and principal pay-downs
Internal Credit Assessment [Domain]
Note 12 - Derivative Instruments - Schedule of Derivative Instruments (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Vested (in shares)
Notes To Financial Statements
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]
Notes To Financial Statements [Abstract]
Nonvested Restricted Stock Shares Activity [Table Text Block]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block]
Number of securities, less than 12 months
Number of securities, more than 12 months
Number of securities
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions
Unrealized loss position, fair value
Other comprehensive gain before reclassifications, net of tax
us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
Amounts reclassified from accumulated other comprehensive income, net of tax
Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block]
us-gaap_LoansReceivableWithVariableRatesOfInterest1
Loans Receivable with Variable Rates of Interest
Unrealized loss position, fair value, less than 12 months
Unrealized loss position, fair value, more than 12 months
States and political subdivisions (nontaxable)
Nontaxable interest income, including any amortization and accretion (as applicable) of discounts and premiums, derived from debt securities issued by municipal governments, local taxing districts and US state government agencies.
fdbc_InterestIncomeRestrictedRegulatorySecurites
Restricted investments in bank stock
Amount, after discount, accretion and premium amortization, of interest income and dividend income on restricted regulatory securities.
us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt
Purchases
Taxable
The aggregate taxable interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.
Nontaxable
The aggregate nontaxable interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.
States and political subdivisions (taxable)
Taxable interest income, including any amortization and accretion (as applicable) of discounts and premiums, derived from debt securities issued by municipal governments, local taxing districts and US state government agencies.
Financial Instruments [Domain]
Financial Asset, Past Due [Member]
Deposits [Member]
Financial Instrument [Axis]
Financial Asset, Not Past Due [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Outstanding, awards (in shares)
Outstanding, awards (in shares)
MBS - GSE residential, fair value
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue
fdbc_PremisesAndEquipmentExpense
Premises and equipment
This element represents premises and equipment expense including depreciation, repairs, rentals, and service contract costs.
Initial allowance on loans purchased with credit deterioration
Automated transaction processing
The amount of automated transaction processing expense.
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Exercised (in shares)
Exercised, awards (in shares)
Transfers from premises and equipment to other assets held-for-sale
Value of premises and equipment transferred to other assets held-for-sale.
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures
Forfeited, awards (in shares)
Right-of-use asset
Amount of increase in right-of-use asset from new lease.
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost
MBS - GSE residential, amortized cost
Notes receivable, gross
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]
Granted, awards (in shares)
Transfers from/(to) loans to/(from) loans held-for-sale, net
Value of loans held-for-sale transferred from (to) loans held in the entity's portfolio in noncash transactions.
Retirement Plan Type [Axis]
Retirement Plan Type [Domain]
Proceeds from sale of bank premises and equipment
Supplemental Employee Retirement Plan [Member]
Nonaccrual with no allowance
fdbc_NumberOfIndividualsWithSplitDollarLifeInsuranceArrangement
Number of Individuals with Split Dollar Life Insurance Arrangement
The number of individuals with split dollar life insurance.
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Nature of Operations [Policy Text Block]
Disclosure of accounting policy for nature of operations.
us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear
Year five
Special Mention [Member]
fdbc_DebtSecuritiesAvailableforsaleAmortizedCostTransferAmount
Debt Securities, Available-for-sale, Amortized Cost, Transfer, Amount
Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale transferred to investment in debt security measured at amortized cost (held-to-maturity).
us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear
Prior
Substandard [Member]
Doubtful [Member]
us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear
Year three
Net change in unrealized gains (losses) on available-for-sale securities
us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear
Year four
us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear
Year two
us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear
Current year
us-gaap_FinancingReceivableRevolving
Revolving loans
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchases of bank premises and equipment
Lease liability
us-gaap_TransferOfOtherRealEstate
Transfers from loans to foreclosed assets held-for-sale
Transfers to loans from foreclosed assets held-for-sale
Principal Forgiveness
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)
us-gaap_FinancingReceivableModificationsRecordedInvestment
Financing Receivable, Modified, Accumulated
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)
Income tax
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage
us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount
Total
Liabilities:
Vesting [Axis]
Vesting [Domain]
us-gaap_IncreaseDecreaseInOperatingLeaseLiability
Operating cash flows from operating leases (Liability reduction)
TDRs amount
us-gaap_Assets
Total assets
Supplemental Disclosures of Cash Flow Information
Principal Forgiveness [Member]
Payment Deferral [Member]
Secured borrowings
us-gaap_LongTermDebtFairValue
Plan Name [Axis]
Short-term borrowings
us-gaap_ShorttermDebtFairValue
Plan Name [Domain]
Loan Restructuring Modification [Axis]
Compensation and Employee Benefit Plans, Other than Share-Based Compensation [Text Block]
Loan Restructuring Modification [Domain]
Unrecognized stock-based compensation expense
Extended Maturity [Member]
us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Net income available to common shareholders
Impaired Financing Receivables [Table Text Block]
Financing Receivable, Modified [Table Text Block]
Share-Based Payment Arrangement [Text Block]
us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation
Repurchase of shares to cover withholdings
us-gaap_ContractWithCustomerAssetNet
Contract with Customer, Asset, after Allowance for Credit Loss, Total
Other assets
us-gaap_PrincipalAmountOutstandingOnLoansManagedAndSecuritized
Loan, Managed and Securitized or Asset-Backed Financing Arrangement, Principal Outstanding
Award Type [Domain]
Direct Financing Lease [Member]
Represents direct financing lease.
Award Date [Axis]
Award Date [Domain]
Award Type [Axis]
Net income
Net income
Net income
Financial Instrument Performance Status [Axis]
Financial Instrument Performance Status [Domain]
Core deposit intangible, net
Performing Financial Instruments [Member]
Nonperforming Financial Instruments [Member]
Loans Past Due and Still Accruing
Financing Receivable Credit Quality Indicators [Table Text Block]
Restricted Stock [Member]
Nonaccrual loans
Financial Asset, 30 to 59 Days Past Due [Member]
Financial Asset, 60 to 89 Days Past Due [Member]
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Table Text Block]
Financial Asset, Aging [Axis]
Financial Asset, Aging [Domain]
Bank Servicing [Member]
Proceeds from sale of foreclosed assets held-for-sale
Bank premises and equipment, net
Goodwill
us-gaap_PaymentsForProceedsFromLoansAndLeases
Net increase in loans and leases
Loans, gross
Financing Receivable, before Allowance for Credit Loss
Interest rate swaps
us-gaap_DerivativeAssets
Fair value
us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock
Increase in restricted investments in bank stock
Derivative Instrument [Axis]
Derivative Contract [Domain]
Cash flows from investing activities:
Total available-for-sale debt securities, fair value
Available-for-sale securities
Available for sale debt security, fair value
Held-to-maturity securities (fair value of $194,251 in 2023; $187,280 in 2022)
Per share data:
Earnings Per Share [Text Block]
Provision for income taxes
Provision for income taxes
Nonaccrual [Member]
Represents nonaccrual.
Accrual [Member]
Represent accrual.
fdbc_NumberOfLoansClassifiedAsTroubledDebtRestructuring
Number of Loans Classified as Troubled Debt Restructuring
The number of loans classified as troubled debt resturtcuring.
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
Due after five years through ten years
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
Due after ten years
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis
Total held-to-maturity securities
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount
Due in one year or less
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
Due after one year through five years
Interest-bearing deposits with financial institutions
Due in one year or less
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue
Due after one year through five years
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
Due after five years through ten years
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
us-gaap_CashAndCashEquivalentsAtCarryingValue
Total cash and cash equivalents
Due after ten years
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Held to maturity securities, gross unrealized losses
Held to maturity securities, gross unrealized gains
Salaries and employee benefits
Cash and due from banks
Data processing and communication
Total held-to-maturity securities
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue
Non-owner Occupied [Member]
Represents non-owner occupied.
Owner Occupied [Member]
Represents owner occupied.
us-gaap_AllocatedShareBasedCompensationExpense
Stock-based compensation expense
fdbc_MaximumPercentageOfCommonStockAvailableForRepurchase
Maximum Percentage of Common Stock, Available for Repurchase
Represents maximum percentage of common stock available for repurchase
us-gaap_DefinedBenefitPlanBenefitObligation
Defined Benefit Plan, Benefit Obligation
fdbc_InterestExpenseIncomeSubordinatedNotesAndDebentures
Secured borrowings
Represents interest expense (income) from subordinated notes and debentures.
us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Ending balance: individually evaluated
Other real estate owned
Represents foreclosed real estate expense (income).
us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Ending balance: collectively evaluated
us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent
Tax effect
Other Loan [Member]
Represents other loan.
Amendment Flag
us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Recoveries
us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Current period gross write-offs
Charge-offs
us-gaap_ComprehensiveIncomeNetOfTax
Total comprehensive income (loss), net of tax
us-gaap_FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease
Provision
City Area Code
Use of Estimates, Policy [Policy Text Block]
us-gaap_FinancialInstrumentsOwnedAtFairValue
Financial Instruments, Owned, at Fair Value
Credit Loss Status [Axis]
Provision (credit) for credit losses on unfunded loan commitments
Provision (credit) for loan losses
Credit Loss Status [Domain]
us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities
Accrued interest payable and other liabilities
Financial Asset Acquired with Credit Deterioration [Member]
Allowance for credit losses on off-balance sheet credit exposures
Off-Balance-Sheet, Credit Loss, Liability
Beginning balance
Ending balance
us-gaap_TreasuryStockSharesAcquired
Treasury Stock, Shares, Acquired (in shares)
us-gaap_GainLossOnSaleOfPropertyPlantEquipment
Net loss from write-down and disposal of bank premises and equipment
us-gaap_SharesOutstanding
Balance (in shares)
Balance (in shares)
Common stock, shares outstanding (in shares)
Financing Receivable, Allowance for Credit Loss [Table Text Block]
us-gaap_GainsLossesOnSalesOfOtherRealEstate
Net gain from sale and write-down of foreclosed assets held-for-sale
us-gaap_GainLossOnSalesOfLoansNet
Loans
us-gaap_IncreaseDecreaseInOtherOperatingAssets
Other assets
Current Fiscal Year End Date
Loans and leases, net (allowance for credit losses of $17,910 in 2023; $17,149 in 2022)
Loans and leases, net
Variable lease cost
us-gaap_LeaseCost
Lease, Cost
Total lease cost
Gain (loss) on sale of investment securities
Available-for-sale debt securities
Net loss from sales of investment securities
Amortization of unrealized losses on securities transferred from available-for-sale to held-to-maturity
Weighted-average discount rate - operating leases
Accrued interest receivable
Document Fiscal Period Focus
Operating lease cost
Document Fiscal Year Focus
Consolidation, Policy [Policy Text Block]
Short-term lease cost
Lease, Cost [Table Text Block]
Gain (loss) on write-down, sale or disposal of:
Right-of-use assets obtained in exchange for new finance lease liabilities
Document Period End Date
Right-of-use assets obtained in exchange for new operating lease liabilities
Weighted average remaining lease term - operating leases (in years) (Year)
Entity File Number
Entity Emerging Growth Company
Document Type
Entity Small Business
Entity Shell Company
us-gaap_DividendsCommonStockCash
Cash dividends declared
Document Information [Line Items]
Document Information [Table]
Entity Filer Category
Entity Current Reporting Status
us-gaap_IncreaseDecreaseInInterestAndDividendsReceivable
Accrued interest receivable
us-gaap_LessorOperatingLeasePaymentsToBeReceived
Total lease payments to be received
Cash surrender value of bank owned life insurance
us-gaap_GoodwillImpairmentLoss
Goodwill, Impairment Loss
Stock-based compensation expense
us-gaap_LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear
2023
Statement of Comprehensive Income [Abstract]
Entity Tax Identification Number
us-gaap_ServicingAsset
Servicing Asset
Entity Central Index Key
us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths
2024
us-gaap_LeaseIncome
Total lease income
Entity Registrant Name
us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears
2025
Liability Class [Axis]
us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears
2026
Fair Value by Liability Class [Domain]
us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears
2027
Entity [Domain]
us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived
Total future minimum lease payments receivable
Legal Entity [Axis]
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivableUndiscountedExcessAmount
Less: Unearned income
Interest income on lease receivables
Lessor, Operating Lease, Payment to be Received, Maturity [Table Text Block]
Entity Address, Address Line One
Lease income - operating leases
Consumer and Residential Portfolio Segments [Member]
Represents the consumer and residential portfolio segments.
Financing receivable, allowance for credit losses
Financing Receivable, Allowance for Credit Loss
Allowance for credit losses on loans
Beginning balance
Ending balance
Commercial and Commercial Real Estate Portfolio Segments [Member]
Represents commercial and commercial real estate portfolio segments.
Entity Address, City or Town
fdbc_SalestypeAndDirectFinancingLeasesLeaseReceivableToBeReceivedAfterYearFour
2028 and thereafter
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).
Entity Address, Postal Zip Code
Foreclosed assets held-for-sale
us-gaap_TreasuryStockCommonValue
Treasury stock, at cost (25,945 shares at March 31, 2023 and 32,663 shares at December 31, 2022)
Entity Address, State or Province
The 2012 Director Stock Incentive Plan [Member]
Represents the 2012 Director Stock Incentive Plan.
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedFourYears
2027
Long-Term Incentive Plan [Member]
Represents Long-Term Incentive Plan (LTIP).
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedRemainderOfFiscalYear
2023
Entity Common Stock, Shares Outstanding
Stock Settled Stock Appreciation Rights SSARs [Member]
Represents stock settled stock appreciation rights (SSARs).
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedNextTwelveMonths
2024
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedTwoYears
2025
us-gaap_OtherForeclosedAssets
Other Repossessed Assets
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedThreeYears
2026
The 2012 Omnibus Stock Incentive Plan [Member]
Represents the 2012 Omnibus Stock Incentive Plan.
Award Date Three [Member]
Represents award date three.
Advertising and marketing
us-gaap_CashSurrenderValueOfLifeInsurance
Cash Surrender Value of Life Insurance
Sales-Type and Direct Financing Leases, Payment to be Received, Maturity [Table Text Block]
Vesting Each Year [Member]
Represents vesting each year.
Professional services
Award Date Two [Member]
Represents award date two.
Re-issuance of common stock through Dividend Reinvestment Plan
Award Date One [Member]
Represents award date one.
Re-issuance of common stock through Dividend Reinvestment Plan (in shares)
fdbc_ImpairedLoansMeasurementInput
Impaired Loans, Measurement Input
The measurement input for impaired loans.
Trading Symbol
Office supplies and postage
The 2002 Employee Stock Purchase Plan [Member]
Represents the 2002 employee stock purchase plan.
Accrued interest receivable
fdbc_AccruedInterestReceivableFairValueDisclosure
Fair Value portion of accrued interest receivable.
Accrued interest payable
fdbc_AccruedInterestPayableFairValueDisclosure
Fair value portion of accrued interest payable.
Deposits with No Stated Maturities [Member]
Represents deposits with no stated maturities.
Time Deposits [Member]
Represents time deposits.
us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale
Originations of loans held-for-sale
Issuance of common stock through Employee Stock Purchase Plan (in shares)
Local Phone Number
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]
us-gaap_GainLossOnDispositionOfAssets
Premises and equipment
us-gaap_TableTextBlock
Notes Tables
Issuance of common stock through Employee Stock Purchase Plan
Proceeds from sale of loans held-for-sale
Issuance of common stock from vested restricted share grants through stock compensation plans (in shares)
Impaired Loans [Member]
Represents impaired loans.
Other Real Estate Owned [Member]
Represents other real estate owned.
Issuance of common stock from vested restricted share grants through stock compensation plans
Landmark Bancorp Inc. [Member]
Represents Landmark Bancorp Inc.
Restricted investments in bank stock
us-gaap_OtherRealEstateOwnedMeasurementInput
Other Real Estate Owned, Measurement Input
Held-to-maturity securities, fair value
Held to maturity securities, fair value
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and shareholders' equity
Reported Value Measurement [Member]
Asset Pledged as Collateral [Member]
fdbc_SplitDollarLifeInsuranceArrangementDeathBenefit
Split Dollar Life Insurance Arrangement, Death Benefit
Amount of death benefit under split dollar life insurance arrangement.
fdbc_SplitDollarLifeInsuranceArrangementDeathBenefitToBePaidToCompany
Split Dollar Life Insurance Arrangement, Death Benefit to be Paid to Company
Amount of death benefit to be paid to the company under split dollar life insurance arrangement.
Retained earnings
Retained Earnings (Accumulated Deficit)
fdbc_SplitDollarLifeInsuranceArrangementAccruedExpense
Split Dollar Life Insurance Arrangement, Accrued Expense
Amount of accrued expense for split dollar life insurance arrangement.
Accumulated other comprehensive loss
Measurement Input, Loss Severity [Member]
Measurement Input, Discount Rate [Member]
fdbc_SplitDollarLifeInsuranceArrangementDeathBenefitToBePaidToInsuredsBeneficiary
Split Dollar Life Insurance Arrangement, Death Benefit to be Paid to Insured's Beneficiary
Amount of death benefit to be paid to insured's beneficiary under the split dollar life insurance arrangement.
Future Branch [Member]
Represents future branch.
Standalone ATM [Member]
Represents standalone ATM.
fdbc_NumberOfLeasesClassifiedAsFinanceLease
Number of Leases Classified as Finance Lease
Number of leases classified as financing lease.
us-gaap_InterestExpense
Total interest expense
Premises and Equipment Expense [Member]
Represents premises and equipment expense.
fdbc_DefinedBenefitPlanNumberOfIndividuals
Defined Benefit Plan, Number of Individuals
The number of individuals participating in defined benefit plan.
Lease Disclosure [Text Block]
The entire disclosure for leases.
Change in:
fdbc_NumberOfPropertiesLeasedUnderOperatingLease
Number of Properties Leased under Operating Lease
The number of properties leased under operating lease.
fdbc_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour
2028 and thereafter
Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).
Less variable payment adjustment
Amount of variable payment adjustment to operating lease liability of the lessee.
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
Derivative Instruments and Hedging Activities Disclosure [Text Block]
fdbc_LessorOperatingLeasePaymentToBeReceivedAfterYearFour
2028 and thereafter
Amount of lease payment to be received by lessor for operating lease after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).
fdbc_LessorNumberOfPropertiesUnderLongtermOperatingLeases
Lessor, Number of Properties Under Long-Term Operating Leases
The number of properties under long-term operating leases as a lessor.
Lessee, Finance Lease, Assets and Liabilities [Table Text Block]
Tabular disclosure of assets and liabilities of finance leases of the lessee.
fdbc_FinanceLeaseLiabilityToBePaidAfterYearFour
2028 and thereafter
Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).
Present value of net future minimum lease payments
Operating lease liabilities
Derivative, Instrument Rate Swap [Member]
Represents the derivative interest rate swap.
Lease Income [Table Text Block]
Tabular disclosure of components of income from lease.
Investment Securities [Member]
Represents investment securities.
Measurement Input, Cost to Sell [Member]
Customer Interest Rate Swaps [Member]
Represents customer interest rate swaps.
Third Party Interest Rate Swaps [Member]
Represents third party interest rate swaps.
Right-of-use assets
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Total future minimum lease payments
Present value of net minimum lease payments
Finance lease obligation
us-gaap_InterestExpenseOtherShortTermBorrowings
Other short-term borrowings
us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
Less amount representing interest
Financing cash flows from finance leases
Repayment of finance lease obligation
Deferred income tax expense (benefit)
Measurement Input Type [Axis]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree
2026
Measurement Input Type [Domain]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour
2027
us-gaap_DebtSecuritiesAvailableForSaleMeasurementInput
Debt Securities, Available-for-Sale, Measurement Input
Leased property under finance leases, net
Leased property under finance leases, net
Valuation Technique, Discounted Cash Flow [Member]
Valuation, Market Approach [Member]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
2024
us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivable
Undiscounted cash flows to be received
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
2025
Valuation Approach and Technique [Axis]
Valuation Approach and Technique [Domain]
us-gaap_InterestExpenseDomesticDeposits
Deposits
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]
us-gaap_ShareBasedCompensation
Stock-based compensation expense
us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear
2023
Business Combinations Policy [Policy Text Block]
Extended Maturity and Principal Forgiveness [Member]
Extended Maturity and Interest Rate Reduction [Member]
Interest expense:
Depreciation, amortization and accretion
Assets
us-gaap_AssetsFairValueDisclosure
us-gaap_InterestAndDividendIncomeOperating
Total interest income
us-gaap_InterestIncomeDepositsWithFinancialInstitutions
Interest-bearing deposits with financial institutions
U.S. government agency and corporations
us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Repurchase of shares to cover withholdings (in shares)
us-gaap_SharesIssued
Shares, Issued (in shares)
TDR percent
Loans held-for-sale
Loan, Held-for-Sale, Fair Value Disclosure
Cash and cash equivalents
us-gaap_CashAndCashEquivalentsFairValueDisclosure
Weighted-Average Term Extension (Month)
us-gaap_DirectFinancingLeaseNetInvestmentInLease
Direct Financing Lease, Net Investment in Lease, before Allowance for Credit Loss
Weighted-Average Interest Rate Reduction
us-gaap_FinancingReceivableRevolvingConvertedToTermLoanWriteoff
Current period gross write-offs, revolving converted to term
us-gaap_FinancingReceivableOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff
Current period gross write-offs, prior
Pension and Other Postretirement Plans, Policy [Policy Text Block]
us-gaap_DirectFinancingLeaseResidualValueOfLeasedAsset
Direct Financing Lease, Residual Value of Leased Asset
us-gaap_FinancingReceivableYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff
Current period gross write-offs, year two
Treasury stock, shares (in shares)
us-gaap_FinancingReceivableYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff
Current period gross write-offs, year three
Investment securities:
us-gaap_FinancingReceivableYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff
Current period gross write-offs, year five
Fair Value, Nonrecurring [Member]
us-gaap_FinancingReceivableRevolvingWriteoff
Current period gross write-offs, revolving
Capital stock, no par value (10,000,000 shares authorized; shares issued and outstanding; 5,665,255 at March 31, 2023; and 5,630,794 at December 31, 2022)
us-gaap_GainLossOnSaleOfLoansAndLeases
Net gain from sales of loans
us-gaap_FinancingReceivableYearOneOriginatedCurrentFiscalYearWriteoff
Current period gross write-offs, current year
us-gaap_FinancingReceivableYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff
Current period gross write-offs, year four
Adjustments to reconcile net income to net cash provided by operating activities:
Measurement Frequency [Axis]
Measurement Frequency [Domain]
Fair Value, Recurring [Member]
Common stock, shares authorized (in shares)
Common stock, shares issued (in shares)
Common stock, par value (in dollars per share)
Common Stock, No Par Value (in dollars per share)
Statistical Measurement [Domain]
Operating cash flows from operating leases (Fixed payments)
Maximum [Member]
Supplemental Disclosures of Non-cash Investing Activities:
Minimum [Member]
Weighted Average [Member]
Product and Service [Axis]
Product and Service [Domain]
Statistical Measurement [Axis]
Operating cash flows from finance leases
Interest income:
Preferred stock authorized 5,000,000 shares with no par value; none issued
Operating lease payments
Preferred stock, shares issued (in shares)
Interest
Preferred stock, par value (in dollars per share)
Preferred stock, shares authorized (in shares)
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]
Portion at Fair Value Measurement [Member]
Estimate of Fair Value Measurement [Member]
us-gaap_NoninterestIncome
Total other income
Measurement Basis [Axis]
Fair Value, Inputs, Level 3 [Member]
Fair Value Hierarchy and NAV [Domain]
Earnings on bank-owned life insurance
Bank Owned Life Insurance Income
Earnings from bank-owned life insurance
Fair Value, Inputs, Level 1 [Member]
Fair Value, Inputs, Level 2 [Member]
Other income:
Fair Value Hierarchy and NAV [Axis]
us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss
Net interest income after provision for credit losses
Provision for credit losses on loans
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
Cash flows from operating activities:
Statement [Line Items]
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
AOCI Attributable to Parent [Member]
Shareholders' equity:
Land [Member]
Restricted investments in bank stock
us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
Long-Lived Tangible Asset [Axis]
Loans and leases, net
us-gaap_LoansReceivableFairValueDisclosure
Long-Lived Tangible Asset [Domain]
Deposit Account [Member]
Credit and Debit Card [Member]
Fair Value Disclosures [Text Block]
Fair Value, by Balance Sheet Grouping [Table Text Block]
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Cash and cash equivalents, beginning
Cash and cash equivalents, ending
Assets:
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Net increase in cash and cash equivalents
us-gaap_Liabilities
Total liabilities
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash provided by financing activities
Transfers and Servicing of Financial Assets, Policy [Policy Text Block]
Executive Officer [Member]
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activities
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash used in investing activities
Interest rate swaps
us-gaap_DerivativeLiabilities
Marketable Securities, Policy [Policy Text Block]
Accounting Standards Update [Domain]
Related allowance
us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation
Repurchase of shares to cover withholdings
Proceeds from employee stock purchase plan participants
Accounting Standards Update [Axis]
Officer [Member]
Cash basis interest income recognized
us-gaap_PaymentsOfDividends
Dividends paid
Interest income recognized
Recorded investment with no allowance
Recorded investment with allowance
Total recorded investment
Impaired Financing Receivable, Recorded Investment
Average recorded investment
Unpaid principal balance
Other
us-gaap_OtherNoninterestExpense
us-gaap_NoninterestExpense
Total other expenses
FDIC assessment
Loan collection
Retained Earnings [Member]
Other Income
us-gaap_TreasuryStockAcquiredAverageCostPerShare
Shares Acquired, Average Cost Per Share (in dollars per share)
Title of Individual [Domain]
Title of Individual [Axis]
Treasury Stock, Common [Member]
Other expenses:
Common Stock Including Additional Paid in Capital [Member]
Accounting Standards Update 2016-13 [Member]
Collateral Held [Domain]
Collateral Pledged [Member]
Equity Components [Axis]
Real Estate [Member]
Equity Component [Domain]
Real Estate Loan [Member]
Collateral Held [Axis]
Class of Financing Receivable [Domain]
Construction Loans [Member]
fdbc_DebtSecuritiesAvailableforsaleAmortizedCostNetOfGainLossTransfer
Debt Securities, Available-for-Sale, Amortized Cost, Net of Gain (Loss), Transfer
Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), net of gains (losses) on transfer.
Home Equity Loan [Member]
fdbc_DebtSecuritiesAvailableforsaleTransferToHeldToMaturityGainLoss
Debt Securities, Available-for-Sale, Transfer to Held to Maturity, Gain (Loss)
Amount of unrealized gain (loss) recognized in earnings from transfer of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) to investment in debt security measured at amortized cost (held-to-maturity).
fdbc_GainFromBankownedLifeInsuranceClaim
Gain From Bank-owned Life Insurance Claim
Gain from bank-owned life insurance claim
Amount of gain from bank owned life insurance claim.
Unallocated Financing Receivables [Member]
Commercial Real Estate Portfolio Segment [Member]
Cumulative-effect adjustment for adoption of ASU 2016-13
Amount of cumulative effect of adoption of new ASU.
Class of Financing Receivable [Axis]
Financing Receivable Portfolio Segment [Domain]
Municipal [Member]
Represents municipal.
fdbc_ReturnOfCashSurrenderValueOfLifeInsurance
Return of Cash Surrender Value of Life Insurance
Amount of return of cash surrender value of life insurance.
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Income before income taxes
Commercial Portfolio Segment [Member]
Schedule of Unamortized Net Costs and Premiums Included in Loans [Table Text Block]
Tabular disclosure of unamortized net costs and premiums included in loans.
Residential Portfolio Segment [Member]
Consumer Portfolio Segment [Member]
Commercial [Member]
Represents commercial.
fdbc_FinancingReceivablesTroubledDebtRestructuringSubsequentDefaultNumberOfContracts
Financing Receivables, Troubled Debt Restructuring, Subsequent Default, Number of Contracts
Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.
Reclassification out of Accumulated Other Comprehensive Income [Member]
fdbc_FinancingReceivablesModificationsNumberOfContracts
Financing Receivables, Modifications, Number of Contracts
Number of financing receivables that have been modified by troubled debt restructurings.
Financing Receivable Portfolio Segment [Axis]
Reclassification out of Accumulated Other Comprehensive Income [Axis]
Reclassification out of Accumulated Other Comprehensive Income [Domain]
Comprehensive Income (Loss) Note [Text Block]
Net increase (decrease) in other borrowings
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]
Nonaccrual with allowance
Amortized cost of financing receivable on nonaccrual status with allowance for credit loss. Excludes net investment in lease.
Secured borrowings
Schedule of Collateral Dependent Loans [Table Text Block]
Tabular disclosure of collateral dependent loans.
Financing Receivable, Held-for-Investment, Foreclosed Asset [Policy Text Block]
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]
Other Collateral [Member]
Represents other collateral.
Financing Receivable [Policy Text Block]
Financing Receivable, Held-for-Sale [Policy Text Block]
Equipment [Member]
The 2022 Omnibus Stock Incentive Plan [Member]
The 2022 Omnibus Stock Incentive Plan.
Revenue from Contract with Customer [Text Block]
Administrative Office [Member]
Administrative Office.
The 2022 Stock Incentive Plan [Member]
Related to the 2022 stock incentive plan.
Schedule of Credit Loss on Unfunded Commitments [Table Text Block]
Tabular disclosure of credit loss on unfunded commitments.
Cash and Cash Equivalents, Policy [Policy Text Block]
Document Quarterly Report
Entity Incorporation, State or Country Code
Accounting Policies [Abstract]
Document Transition Report
Short-term borrowings
Entity Interactive Data Current
Dividends (in dollars per share)
Security Exchange Name
Other Expense [Member]
Title of 12(b) Security
PA shares tax
Amount of PA shares tax (benefit.
fdbc_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesPositiveChangeInCollateralValueNumberOfLoans
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Positive Change In Collateral Value , Number of Loans
Represents number of loans for positive change in collateral value for certain loans acquired in transfer note accounted as debt securities.
Ending balance: collectively evaluated
The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.
AOCI, Gain (Loss), Debt Securities, Securities Transferred To Held-to-maturity [Member]
Represents securities transferred to held to maturity for gain (loss) of accumulated other comprehensive income.
Income Statement Location [Axis]
Deposits
us-gaap_DepositsFairValueDisclosure
Income Statement Location [Domain]
Ending balance: individually evaluated for impairment
Ending balance: individually evaluated
Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
Held-to-maturity securities
fdbc_HeldToMaturitySecuritiesFairValueDisclosure
Fair value of investment in debt security measured at amortized cost (held-to-maturity).
Common Stock Outstanding [Member]
Represents common stock outstanding.
Accrued interest payable and other liabilities
us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment
Weighted Average Number of Shares Outstanding, Diluted, Adjustment (in shares)
Pledging Purpose [Domain]
us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization
Less accumulated depreciation and amortization
us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)
us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Weighted-average common and potentially dilutive shares outstanding (in shares)
Pledging Purpose [Axis]
Property and equipment
us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization
us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss
Financing Receivable, Accrued Interest, after Allowance for Credit Loss
Asset Class [Axis]
Asset Class [Domain]
Statement [Table]
Statement of Financial Position [Abstract]
Net income - diluted (in dollars per share)
Diluted EPS (in dollars per share)
us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Weighted-average common shares outstanding (in shares)
us-gaap_FinancingReceivableRevolvingConvertedToTermLoan
Revolving loans converted to term
us-gaap_FinancingReceivableUnamortizedLoanFeeCost
Financing Receivable, Unamortized Loan Cost (Fee)
Business Acquisition [Axis]
Net income - basic (in dollars per share)
Basic EPS (in dollars per share)
Business Acquisition, Acquiree [Domain]
us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss
Statement of Cash Flows [Abstract]
us-gaap_FinancingReceivableUnamortizedPurchasePremiumDiscount
Financing Receivable, Unamortized Purchase Premium (Discount)
Statement of Stockholders' Equity [Abstract]
Income Statement [Abstract]
Other comprehensive income (loss)
Other comprehensive income (loss), net of tax
Financing Receivable, Nonaccrual [Table Text Block]
Interest-bearing
Interest on lease liabilities
Fiduciary and Trust [Member]
us-gaap_Deposits
Total deposits
us-gaap_FinanceLeaseLiabilityPaymentsDue
Total minimum lease payments (a)
Non-interest-bearing
Amortization of right-of-use assets
us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss
Debt Securities, Held-to-Maturity, Allowance for Credit Loss
Investments Classified by Contractual Maturity Date [Table Text Block]
us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount
Less amount representing interest (b)
Weighted average years (Year)
us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths
2024
us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo
2025
Net (decrease) increase in deposits
us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree
2026
us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour
2027
Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]
us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
Net unrealized gain (loss)
Accounting Standards Update and Change in Accounting Principle [Text Block]
Weighted-average discount rate - finance leases
us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax
Reclassification adjustment for net losses realized in income
Finance Lease, Liability, to be Paid, Maturity [Table Text Block]
Direct Financing Lease Net of Unearned Lease Revenue [Member]
Represents direct financing lease net of unearned lease revenue.
fdbc_FinancingReceivableUnearnedLeaseRevenue
Unearned lease revenue
Represents unearned lease revenue for financing receivable.
us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear
2023
Fair Value Measurements, Nonrecurring [Table Text Block]
Unrealized holding gain (loss) on available-for-sale debt securities
Weighted-average remaining lease term - finance leases (in years) (Year)
Amortization of unrealized loss on held-to-maturity securities
Contractual Interest Rate Reduction [Member]
Cash flows from financing activities:
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Proceeds from death benefits received on bank-owned life insurance
Proceeds from Life Insurance Policy
Nonrecourse [Member]
Other comprehensive gain (loss), before tax:
Pledged Status [Domain]
Pledged Status [Axis]
us-gaap_StockholdersEquity
Total shareholders' equity
Balance
Balance
Principal portion of lease payments received under direct finance leases
Class of Stock [Axis]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Investment Advisory, Management and Administrative Service [Member]
Recourse [Member]
us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Available for sale securities, gross unrealized losses
Available for sale debt securities, gross unrealized gains
Financial Service, Other [Member]
Recourse Status [Domain]
Recourse Status [Axis]
Available for sale securities, amortized cost
Total available-for-sale debt securities, amortized cost
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
Due after one year through five years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
Due after five years through ten years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
Due after ten years