Document And Entity Information Dividend yield(1) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate After 10 years, available for sale, fair value Note To Financial Statement Details Textual us-gaap_DerivativeGainLossOnDerivativeNet IRLCs Asset Derivatives [Member] Information pertaining to asset derivatives. Significant Accounting Policies Note 2 - Summary of Significant Accounting Policies Due in 1 year or less, available for sale, amortized cost Mortgage-backed Securities, Issued by Private Enterprises [Member] Note 5 - Investment Securities Risk-free interest rate(4) Collateralized Mortgage Obligations [Member] Note 6 - Loans Receivable and Allowance for Loan Losses Due in 1 year or less, available for sale, fair value Note 7 - Fair Value of Financial Instruments After 1 year to 5 years, available for sale, fair value Liability Derivatives [Member] Information pertaining to liability derivatives. Note 8 - Changes in Accumulated Other Comprehensive Income (Loss) By Component (1) After 5 years to 10 years, available for sale, fair value Collateralized Mortgage Backed Securities [Member] Note 9 - Goodwill and Other Intangibles Not Designated as Hedging Instrument [Member] Note 10 - Derivatives and Risk Management Activities Note 11 - Revenue Recognition Unrealized loss on securities Note 2 - Summary of Significant Accounting Policies - Valuation Assumptions (Details) Note 2 - Summary of Significant Accounting Policies - Stock-based Compensation (Details) Collateralized Debt Obligations [Member] Unrealized gains (losses) on securities (pre-tax ($6,708), and $971 respectively) Note 2 - Summary of Significant Accounting Policies - Calculation of EPS (Details) Hedging Designation [Axis] Expected volatility Hedging Designation [Domain] Note 2 - Summary of Significant Accounting Policies - Anti-dilutive Securities (Details) Note 5 - Investment Securities - Unrealized Gain (Loss) on Investments (Details) Stock held by deferred compensation plan (in shares) The number of shares of the entity's stock held in deferred compensation plan for payment of future benefits. Note 5 - Investment Securities - Investment Securities by Contractual Maturity (Details) frbk_FinancingReceivableModificationsIncreaseInPrincipalBalance Financing Receivable, Modifications, Increase in Principal Balance Amount of investment in financing receivables increased in related to the modification. Note 5 - Investment Securities - Credit-related Impairment Losses on Securities (Details) Note 5 - Investment Securities - Securities in a Continuous Unrealized Loss Position (Details) Asset-backed Securities [Member] Converted From Line of Credit to Term Loan With Five Year Maturity [Member] Loan modification for conversion of a financing receivable from line of credit to term loan with five year maturity. Note 5 - Investment Securities - Trust Preferred Securities (Details) Expected life(5) (years) (Year) Note 6 - Loans Receivable and Allowance for Loan Losses - Gross Loans by Major Categories (Details) Note 6 - Loans Receivable and Allowances for Loan Losses - Activity in Allowance for Loan Losses (Details) Increase in Principal Balance and Reduction in Interest Rate [Member] Loan modification for an increase in the principal balance and reduction in the interest rate. Note 6 - Loans Receivable and Allowance for Loan Losses - Impaired Loans (Details) Note 6 - Loans Receivable and Allowance for Loan Losses - Impaired Loans Additional Information (Details) US States and Political Subdivisions Debt Securities [Member] Accrued interest receivable Note 6 - Loans Receivable and Allowance for Loan Losses - Past Due Loans (Details) Non-compete agreements, additions/adjustments Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Note 6 - Loans Receivable and Allowance for Loan Losses - Loans by Internal Risk Rating (Details) Note 6 - Loans Receivable and Allowance for Loan Losses - Non-accrual Loans (Details) Note 6 - Loan Receivables and Allowance for Loan Losses - Troubled Debt Restructurings (Details) Mortgage loans held for sale , at fair value Note 7 - Fair Value of Financial Instruments - Financial Assets Measured at on a Recurring Basis (Details) Note 7 - Fair Value of Financial Instruments - SBA Servicing Assets Activity (Details) Note 7 - Fair Value of Financial Instruments - Assets Measured on a Recurring Basis Using Significant Unobservable Inputs (Details) Share-based Compensation, Activity [Table Text Block] Note 7 - Fair Value of Financial Instruments - Assets Measured on a Nonrecurring Basis (Details) Proceeds from the maturity or call of securities held to maturity Pass [Member] Note 7 - Fair Value of Financial Instruments - Quantitative Information about Level 3 Assets (Details) Note 7 - Fair Value of Financial Instruments - Mortgage Loans Held for Sale (Details) Subprime [Member] Note 7 - Fair Value of Financial Instruments - SBA Servicing Assets Sensitivity Analysis (Details) Other Debt Obligations [Member] Note 7 - Fair Value of Financial Instruments - Fair Values of Financial Instruments (Details) Note 8 - Changes in Accumulated Other Comprehensive Income (Loss) By Component (1) - Accumulated Other Comprehensive Loss (Details) Agency Mortgage-backed Securities [Member] Information pertaining to agency mortgage-backed securities. Note 9 - Goodwill and Other Intangibles - Summary of Goodwill and Other Intangibles (Details) Note 10 - Derivatives and Risk Management Activities - Amounts Recorded in Statement of Financial Condition (Details) Note 10 - Derivatives and Risk Management Activities - Derivative Instrument Gain (Loss) Recorded in Statement of Income (Details) Note 11 - Revenue Recognition -Non-interest Income Segregated by Revenue Streams (Details) Internal Credit Assessment [Axis] US Government Agencies Debt Securities [Member] Notes To Financial Statements Internal Credit Assessment [Domain] Proceeds from the maturity or call of securities available for sale Notes To Financial Statements [Abstract] Corporate Debt Securities [Member] us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1 Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax Amounts reclassified from accumulated other comprehensive income to net income (2) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares us-gaap_PaymentsToAcquireHeldToMaturitySecurities Purchase of investment securities held to maturity Number of unvested stock options (in shares) Financial Instruments [Domain] Financial Instrument [Axis] Goodwill and Intangible Assets Disclosure [Text Block] Interest income recognized us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans us-gaap_DerivativeAssetNotionalAmount IRLCs No specific maturity date, available for sale, fair value us-gaap_DerivativeLiabilityNotionalAmount IRLCs No specific maturity date, available for sale, amortized cost us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance us-gaap_PolicyTextBlockAbstract Accounting Policies Special Mention [Member] Substandard [Member] Doubtful [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Premises and equipment expenditures us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Allowance for Credit Losses [Text Block] Measurement Input, Liquidation Expenses [Member] Measurement input using the value of liquidation expenses. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Troubled debt restructurings Financing Receivable, Modifications, Recorded Investment us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 Financing Receivable, Modifications, Subsequent Default, Number of Contracts us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 Financing Receivable, Modifications, Pre-Modification Recorded Investment us-gaap_Assets Total Assets Supplemental disclosures Impaired Financing Receivables, Average Recorded Investment and Interest Income, Accrual Method [Table Text Block] Tabular disclosure of impaired financing receivables. Includes (1) the average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses; (2) the amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired. Plan Name [Axis] Plan Name [Domain] us-gaap_FinancingReceivableModificationsNumberOfContracts2 Financing Receivable, Modifications, Number of Contracts Amount remaining to be recognized as expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Loan Restructuring Modification [Axis] Loan Restructuring Modification [Domain] Impaired Financing Receivables [Table Text Block] Troubled Debt Restructurings on Financing Receivables [Table Text Block] Legal Matters and Contingencies [Text Block] us-gaap_CapitalizedContractCostNet Capitalized Contract Cost, Net, Total Other assets Restricted stock, at cost Net income Net income us-gaap_FiniteLivedIntangibleAssetsNet Non-compete agreements Non-compete agreements Loans receivable greater than 90 days and accruing Financing Receivable Credit Quality Indicators [Table Text Block] Loans receivable, current Convertible Debt Securities [Member] Loans receivable, total past due Employee Stock Option [Member] Non-accrual loans Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Financing Receivables, 30 to 59 Days Past Due [Member] Financing Receivables, 60 to 89 Days Past Due [Member] Antidilutive Securities [Axis] Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Antidilutive Securities, Name [Domain] Past Due Financing Receivables [Table Text Block] Goodwill, additions/adjustments Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Domain] Net proceeds from sale of other real estate owned Effect on fair value of a 20% increase us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf20PercentAdverseChangeInDiscountRate Premises and equipment, net Goodwill Goodwill Goodwill us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf20PercentAdverseChangeInPrepaymentSpeed Effect on fair value of a 20% increase Commitments to extend credit Effect on fair value of a 10% increase us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf10PercentAdverseChangeInDiscountRate Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block] us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf10PercentAdverseChangeInPrepaymentSpeed Effect on fair value of a 10% increase us-gaap_DerivativeFairValueOfDerivativeLiability IRLCs us-gaap_DerivativeFairValueOfDerivativeAsset IRLCs Derivative asset Derivative Asset us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock Net purchase of restricted stock Loan and Servicing Fees [Member] Represents fees relating to loans and servicing of loans. Derivative Instrument [Axis] Derivative Contract [Domain] Cash flows from investing activities Investment securities available for sale, at fair value Total, available for sale, fair value Total, held to maturity, amortized cost Investment securities held to maturity, at amortized cost (fair value of $502,591 and $463,799, respectively) Investment securities held to maturity, at amortized cost Net income per share Interest and Fees [Member] Represents information pertaining to the income statement line item, Interest and Fees. us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments Income before provision (benefit) for income taxes Decrease in accrued interest payable and other liabilities Provision (benefit) for income taxes us-gaap_MortgageLoansInProcessOfForeclosureAmount Mortgage Loans in Process of Foreclosure, Amount Other real estate owned, net Real Estate Acquired Through Foreclosure Money market and savings Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts. Also includes amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs). Cumulative OTTI Life to Date Beginning Balance Ending Balance Additional credit-related impairment loss on securities for which an other-than-temporary impairment was previously recognized Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses frbk_InterestExpenseOnMoneyMarketAndSavingsDeposits Money market and savings Interest expense incurred on all money market deposits and Interest expense incurred on all savings account deposits. Fair Value Option, Disclosures [Table Text Block] After 5 years to 10 years, held to maturity, amortized cost Mandatory Forward Loan Sales Commitments [Member] Represents information pertaining to mandatory forward loan sales commitments. After 10 years, held to maturity, amortized cost Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block] Best Efforts Forward Loan sales Commitments [Member] Represents information pertaining to best efforts forward loan sales commitments. us-gaap_ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions Fair value adjustments Taxes, other Due in 1 year or less, held to maturity, amortized cost Insurance After 1 year to 5 years, held to maturity, amortized cost Interest bearing deposits with banks Due in 1 year or less, held to maturity, fair value After 1 year to 5 years, held to maturity, fair value After 5 years to 10 years, held to maturity, fair value After 10 years, held to maturity, fair value Unrealized gains us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss Investment securities held to maturity, gross unrealized losses Investment securities held to maturity, gross unrealized gains Salaries and employee benefits Schedule of Servicing Assets at Fair Value [Table Text Block] Cash and due from banks Aggregate Unpaid Principal Balance Amount of unpaid principal balance of mortgage loans held for sale. Stock based compensation expense recognized Realized gains Excess Carrying Amount Over Aggregate Unpaid Principle Balance The amount of mortgage loans held for sale in excess of the unpaid principal balance. Amortization of net unrealized holding losses to income during the period, pre-tax The amount of expense charged against earnings by an entity to record the amortization of gains and losses on securities before tax. Loans evaluated individually Legal Amortization of net unrealized holding losses during the period (pre-tax $39, and $42 respectively) The amount of expense charged against earnings by an entity to record the amortization of gains and losses on securities net of tax. Loans evaluated collectively Write down of other real estate owned Amount of other real estate owned that have been written off. Allowance for loan losses, individually evaluated for impairment Allowance for loan losses, collectively evaluated for impairment Amendment Flag Accretion of discounts on retained SBA loans The SBA servicing asset is initially recorded when loans are sold and the servicing rights are retained and recorded on the balance sheet. Updated fair values are obtained on a quarterly basis and adjustments are presented as loan advisory and servicing fees on the consolidated statement of operations. As a noncash item, this element is an adjustment to net income when calculating cash provided by or used in operations. Recoveries Other comprehensive income (loss), net of tax us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs Charge-offs us-gaap_ComprehensiveIncomeNetOfTax Total comprehensive income (loss) Fair value adjustments on SBA servicing assets The SBA servicing asset is initially recorded when loans are sold and the servicing rights are retained and recorded on the balance sheet. Updated fair values are obtained on a quarterly basis and adjustments are presented as loan advisory and servicing fees on the consolidated statement of operations. As a noncash item, this element is an adjustment to net income when calculating cash provided by or used in operations. frbk_NumberOfWhollyOwnedSubsidiary Number of Wholly Owned Subsidiary Number of wholly owned subsidiary of the entity. Use of Estimates, Policy [Policy Text Block] Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance [Table Text Block] Tabular disclosure for other derivative instruments not designated as hedging instruments of the location and amount of gains and losses reported in the statement of financial performance. New Accounting Pronouncements, Policy [Policy Text Block] frbk_NumberOfTrustPreferredSecuritiesIssued Number of Trust Preferred Securities Issued Number of trust preferred securities issued by the entity. Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Position [Table Text Block] Tabular disclosure for other derivative instruments not designated as hedging instruments of the location and fair value amounts of the instruments reported in the statement of financial position. frbk_NumberOfUnconsolidatedSubsidiaries Number of Unconsolidated Subsidiaries Number of unconsolidated subsidiaries of the entity. The 2005 Plan [Member] The reporting entity's Stock Option and Restricted Stock Plan or the 2015 Plan. Restricted stock Stock Options and Restricted Stock Plan [Member] Represents the Stock Options and Restricted Stock Plan. The 2014 Republic First Bancorp, Inc. Equity Incentive Plan [Member] Represents the 2014 Republic First Bancorp, Inc. Equity Incentive Plan. Common stock, shares outstanding (in shares) Preferred stock, shares outstanding (in shares) frbk_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValueAmount Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value, Amount Amount of the weighted average grant-date fair value of options granted during the period. Allowance for Credit Losses on Financing Receivables [Table Text Block] frbk_MinimumPercentageOfOutstandingSharesAsAnnualAdjustment Minimum Percentage of Outstanding Shares as Annual Adjustment Refers to percentage of outstanding shares as an annual adjustment available for grant under the terms of the plan. Held to maturity securities in a continuous unrealized loss position, fair value Gain on sales of SBA loans frbk_TreasuryBondTermOnWhichRiskFreeInterestRateIsBased Treasury Bond Term On Which Risk Free Interest Rate is Based Refers to treasury bond term on which risk free interest rate is based. Current Fiscal Year End Date frbk_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateTerm Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Term The term on which the expected volatility rate to determine fair value is based on. frbk_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOptionsForfeitedWeightedAverageGrantDateFairValueAmount Share-based Compensation Arrangement by Share-based Payment Award, Options, Options Forfeited, Weighted Average Grant Date Fair Value, Amount Amount of weighted average grant-date fair value of options forfeited during the period. Held to maturity securities in a continuous unrealized loss position, less than 12 months, fair value us-gaap_GainLossOnSaleOfMortgageLoans Gains on mortgage loans originated for sale Held to maturity securities in a continuous unrealized loss position, 12 months or more, fair value Document Fiscal Period Focus Document Fiscal Year Focus Risks and Uncertainties and Certain Significant Estimates [Policy Text Block] Description of the business risk faced by the entity due to concentration of revenue from a single source. Document Period End Date Assumed forfeiture rate(6) The estimated forfeiture rate of the underlying shares over the option's term. Fair value of unvested stock options Represents the fair value of unvested stock options. No specific maturity date, held to maturity, fair value Document Type frbk_NumberOfSecuritiesInInvestmentPortfolio Number of Securities in Investment Portfolio Refers to number of securities included in investment portfolio. Document Information [Line Items] Document Information [Table] Lowest Credit Rating Assigned No specific maturity date, held to maturity, amortized cost Other loans held for sale Represents other loans held for sale. Entity Filer Category Entity Current Reporting Status frbk_SecuritiesContinuousLossPositionAccumulatedLoss Securities, Continuous Loss Position, Accumulated Loss Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity and available-for-sale in a continuous loss position. Entity Voluntary Filers Entity Well-known Seasoned Issuer us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet Increase in accrued interest receivable and other assets Held to maturity securities in a continuous unrealized loss position, 12 months or more, unrealized losses frbk_SecuritiesContinuousUnrealizedLossPositionFairValue Securities, Continuous Unrealized Loss Position, Fair Value This item represents the fair value of securities categorized as held-to-maturity and available-for-sale which are in an unrealized loss position. Held to maturity securities in a continuous unrealized loss position, unrealized losses Contract Acquisition Costs [Member] Represents contract acquisition costs. us-gaap_GoodwillImpairmentLoss Goodwill, Impairment Loss Other Non-interest Income From Customers [Member] Non interest income derived from contracts with customers which is within the scope of ASC 606. Held to maturity securities in a continuous unrealized loss position, less than 12 months, unrealized losses Fair Value of SBA Servicing Asset SBA Servicing Assets Beginning balance, January 1st Ending balance, March 31st Stock based compensation Statement of Comprehensive Income [Abstract] us-gaap_ServicingAsset Servicing Asset, Total Entity Central Index Key Capitalized Contract Cost [Axis] Depreciation and amortization Entity Registrant Name Capitalized Contract Cost [Domain] Liability Class [Axis] Fair Value by Liability Class [Domain] Entity [Domain] Legal Entity [Axis] Non-interest income (out-of-scope of Topic 606) Represents portion of non-interest income that is not within the scope of ASC 606. us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue Balance Balance Amortization of intangible assets Amortization us-gaap_FinancingReceivableAllowanceForCreditLosses Total allowance for loan losses Beginning balance Ending balance us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales Proceeds from sales us-gaap_OtherRealEstateAndForeclosedAssets Other real estate owned us-gaap_TreasuryStockValue Treasury stock at cost (503,408 shares as of March 31, 2018 and December 31, 2017) us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements Paydowns Schedule of Trust Preferred Securities [Table Text Block] Tabular disclosure of unrealized losses and collateral information on pooled trust preferred investments. us-gaap_IncreaseDecreaseInNotesReceivables Net increase in loans Entity Common Stock, Shares Outstanding (in shares) Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Advertising Loans receivable (net of allowance for loan losses of $6,650 and $8,599 respectively) Net loans receivable Loans receivable Total loans receivable Professional fees us-gaap_LoansAndLeasesReceivableDeferredIncome Deferred costs (fees) Loans receivable, allowance for loan losses Allowance for loan losses Trading Symbol Data processing Conversion of subordinated debt to common stock us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecuritiesNetOfAdjustments Occupancy Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Conversion of subordinated debt, shares (in shares) Options exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period us-gaap_TableTextBlock Notes Tables us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale Mortgage loans originated for sale Options exercised Proceeds from sales of mortgage loans originated for sale Conditional prepayment rate us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross TPREF Funding II [Member] Represents TPREF Funding II. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Class / Tranche Represents the class and trance of trust preferred securities. Liquidation expenses Number of Banks Currently Performing Represents the number of banks currently performing. Deferrals / Defaults as % of Current Balance Represents the current number of deferrals and defaults as a percentage of the current collateral balance. Investment securities held to maturity, at fair value Total, held to maturity, fair value Conditional Default Rates for 2018 and beyond Represents conditional default rates for 2017 and beyond. us-gaap_LiabilitiesAndStockholdersEquity Total Liabilities and Shareholders’ Equity Reported Value Measurement [Member] us-gaap_CashCashEquivalentsAndFederalFundsSold Cash and cash equivalents Cash and cash equivalents, beginning of year Cash and cash equivalents, end of period Construction and Land Development Portfolio Segment [Member] Represents the construction and land development portfolio segment. Owner Occupied Real Estate [Member] Represents the owner occupied real estate. Accumulated deficit Accumulated other comprehensive loss Measurement Input, Prepayment Rate [Member] Measurement Input, Discount Rate [Member] us-gaap_InterestExpense Total interest expense Amortization of debt issuance costs us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Derivative Instruments and Hedging Activities Disclosure [Text Block] us-gaap_InterestExpenseBorrowings Other borrowings us-gaap_IntangibleAssetsNetIncludingGoodwill Total Total Discount rate Measurement Input Type [Axis] Measurement Input Type [Domain] Valuation Technique, Discounted Cash Flow [Member] Valuation, Market Approach [Member] us-gaap_InterestExpenseTimeDeposits Time deposits Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] us-gaap_InterestExpenseNegotiableOrderOfWithdrawalNOWDeposits Demand-interest bearing us-gaap_ShareBasedCompensation Stock based compensation Conversion of subordinated debt to common stock Non-compete agreements, amortization period (Year) Earnings Per Share, Policy [Policy Text Block] Interest expense: us-gaap_DepreciationAmortizationAndAccretionNet Depreciation and amortization Fair Value us-gaap_InterestAndDividendIncomeOperating Total interest income us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments Amortization of premiums on investment securities Interest on federal funds sold and other interest-earning assets Carrying Amount Mortgages Held-for-sale, Fair Value Disclosure Loans held for sale us-gaap_LoansHeldForSaleFairValueDisclosure Standby letters-of-credit Cash and cash equivalents Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations Subordinated debt Interest and dividends on taxable investment securities Interest and dividends on tax-exempt investment securities Treasury stock (in shares) us-gaap_ImpairmentOfInvestments Impairment charges on Level 3 Fair Value, Measurements, Nonrecurring [Member] Number of Loans Cumulative number of financing receivables that have been modified by troubled debt restructurings. Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Common stock, par value $0.01 per share: 100,000,000 shares authorized; shares issued 59,252,198 as of March 31, 2018 and 57,518,609 as of December 31, 2017; shares outstanding 58,723,353 as of March 31, 2018 and 56,989,764 as of December 31, 2017 Troubled debt restructurings, accrual status Recorded investment in financing receivables that have undergone troubled debt restructuring and are accruing. Interest and fees on tax-exempt loans Troubled debt restructurings, non-accrual status Recorded investment in financing receivables that have undergone troubled debt restructuring and are not accruing. Adjustments to reconcile net income to net cash provided by operating activities: Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Interest and fees on taxable loans us-gaap_ServicingAssetAtFairValueAdditions Additions Fair Value, Measurements, Recurring [Member] Common stock, shares authorized (in shares) Common stock, shares issued (in shares) Common stock, par value (in dollars per share) frbk_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf10PercentAdverseChangeInKeyAssumptionsPercent Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Key Assumptions, Percent The measurement of the hypothetical financial impact of a 10 percent adverse changes in key assumptions on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. frbk_LoansHeldforsaleWritedown Loans Held-for-sale, Write-down The amount of write-down on loans held-for-sale during the period. frbk_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf20PercentAdverseChangeInKeyAssumptions Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 20 Percent Adverse Change in Key Assumptions The measurement of the hypothetical financial impact of a 20 percent adverse changes in key assumptions on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. SBA Servicing Assets [Member] Represents SBA servicing assets. Demand - non-interest bearing Range [Domain] Maximum [Member] Minimum [Member] frbk_ImpairedLoansReceivableFairValueDisclosure Impaired loans This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents impaired loan receivable as presented on the statement of financial position which may include mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts, or any other loans which are due the Company as of the balance sheet date. Weighted Average [Member] Product and Service [Axis] Product and Service [Domain] Accumulated Net Investment Gain (Loss) on Securities Transferred from Available-for-Sale to Held-to-Maturity [Member] Represents accumulated net investment gain (loss) on securities transferred from available-for-sale to held-to-maturity. Range [Axis] us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages Interest and Fee Income, Loans Held-for-sale, Mortgages Preferred stock, par value $0.01 per share: 10,000,000 shares authorized; no shares issued and outstanding Prepayment Speed Preferred stock, shares issued (in shares) Weighted Average Remaining Term (years) (Year) Interest paid Off-Balance Sheet Data Preferred stock, shares authorized (in shares) Weighted Average Discount Rate frbk_AccruedInterestReceivableAtFairValue Accrued interest receivable The fair value of accrued interest on loans and investments. Demand - interest bearing Portion at Fair Value Measurement [Member] [Default] Time This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item includes the amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts. Preferred stock par value (in dollars per share) Estimate of Fair Value Measurement [Member] Demand, savings and money market This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure. This item represents the aggregate of all deposits in demand deposits, saving deposits, and money market funds as of the balance sheet date. Other non-interest income Fixed Rate SBA Loans [Member] Represents the fixed rate for SBA loans. Total non-interest income frbk_AccruedInterestPayableAtFairValue Accrued interest payable The fair value of accrued interest payable. Non-interest income SBA Servicing Asset Measurement Basis [Axis] Adjustable Rate SBA Loans [Member] Represents the adjustable rate for SBA loans. Composition of SBA loans serviced for others Small Business Administration loans presented as a percentage of an entity's total SBA loans. Fair Value, Inputs, Level 3 [Member] Composition of SBA Loans Serviced for Others Impaired Loans [Member] Represents impaired loans. Fair Value Hierarchy and NAV [Domain] Other Real Estate Owned [Member] Represents other real estate owned. Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Non-interest income: Fair Value Hierarchy and NAV [Axis] Sales Price Valuation Technique [Member] Represents the sale price valuation technique. frbk_PaymentsForSBALoansOriginatedForSale SBA loans originated for sale Amount of cash outflow for payments for SBA loans originated for sale us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss Net interest income after provision for loan losses Proceeds from sales of SBA loans originated for sale Amount of cash inflow for the proceeds from sales of SBA loans originated for sale. frbk_GainLossOnSalesOfSbaLoansOriginatedForSale Gains on sales of SBA loans originated for sale Amount of gain (loss) on sales of SBA loans originated for sale. Provision for loan losses us-gaap_InterestIncomeExpenseNet Net interest income Cash flows from operating activities Statement [Line Items] us-gaap_NumberOfReportableSegments Number of Reportable Segments Additional paid in capital Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] us-gaap_DeferredCompensationEquity Stock held by deferred compensation plan (25,437 shares as of March 31, 2018 and December 31, 2017) AOCI Attributable to Parent [Member] Shareholders’ Equity Financial liabilities: Loans receivable, net Segment Reporting Disclosure [Text Block] Deposit Account [Member] Mortgage Banking [Member] Financial assets: Fair Value Disclosures [Text Block] Fair Value, by Balance Sheet Grouping [Table Text Block] ASSETS us-gaap_Liabilities Total Liabilities us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash provided by financing activities us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities Other liabilities us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease Net (decrease) increase in cash and cash equivalents Additions/adjustments Amount of goodwill and intangible assets acquired during period. Derivatives, Policy [Policy Text Block] Derivative liability Derivative Liability Accrued interest payable Related allowance With no related allowance recorded - Interest income recognized With related allowance recorded - Interest income recognized With no related allowance - Recorded investment Interest income: With related allowance - Recorded investment Recorded investment With no related allowance recorded - Average recorded investment With related allowance recorded - Average recorded investment Average recorded investment With no related allowance - Unpaid principal balance With related allowance - Unpaid principal balance Unpaid principal balance Other operating expenses us-gaap_NoninterestExpense Total non-interest expense Regulatory assessments and costs Appraisal and other loan expenses Retained Earnings [Member] Net proceeds from exercise of stock options Proceeds from Stock Options Exercised Other real estate owned Appraised Value of Collateral [Member] Valuation technique using the appraised value of collateral. Deferred Compensation, Share-based Payments [Member] Treasury Stock [Member] Non-interest expenses: Additional Paid-in Capital [Member] Common Stock [Member] Equity Components [Axis] Equity Component [Domain] us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1 Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Other Liabilities [Member] Unallocated Financing Receivables [Member] Commercial Real Estate Portfolio Segment [Member] Other Assets [Member] Financing Receivable Portfolio Segment [Domain] Commercial Portfolio Segment [Member] Residential Portfolio Segment [Member] Consumer Portfolio Segment [Member] Financing Receivable Portfolio Segment [Axis] Comprehensive Income (Loss) Note [Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Loans and Leases Receivable, Mortgage Banking Activities, Policy [Policy Text Block] Subordinated debt Disaggregation of Revenue [Table Text Block] Revenue from Contract with Customer [Text Block] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Accounting Policies [Abstract] Significant Accounting Policies [Text Block] Short-term borrowings Income Statement Location [Axis] Income Statement Location [Domain] Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Increase in short-term borrowings frbk_FairValueAdjustmentForMortgageLoansOriginatedForSale Fair value adjustment for mortgage loans originated for sale The amount of fair value adjustment for mortgage loans originated for sale. us-gaap_PaymentsToAcquireAvailableForSaleSecurities Purchase of investment securities available for sale Weighted average shares outstanding (in shares) us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities Proceeds from Sale of Available-for-sale Securities, Total Reclassification due to the adoption of ASU 2018-02 Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income The amount of reclassification of certain tax effects from accumulated other comprehensive income. Anti-dilutive securities (in shares) Weighted average shares outstanding (including dilutive CSEs) (in shares) Asset Class [Axis] Asset Class [Domain] Statement [Table] Scenario [Axis] Statement of Financial Position [Abstract] Diluted (in dollars per share) Scenario, Unspecified [Domain] Basic (in dollars per share) Statement of Cash Flows [Abstract] Statement of Stockholders' Equity [Abstract] Income Statement [Abstract] Other comprehensive income/loss, net of tax Net current-period other comprehensive income (loss) Schedule of Financing Receivables, Non Accrual Status [Table Text Block] Available for sale securities in a continuous unrealized loss position, unrealized losses us-gaap_Deposits Total Deposits us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1 Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Total Available for sale securities in a continuous unrealized loss position, less than 12 months, unrealized losses Available for sale securities in a continuous unrealized loss position, 12 months or more, unrealized losses AltA [Member] A credit rating for mortgages that falls between prime and subprime. Investments Classified by Contractual Maturity Date [Table Text Block] Mortgage Banking Income [Member] Primary financial statement caption encompassing mortgage banking income. frbk_SharebasedCompensationArrangementBySharebasedPaymentAwardPeriodForDeterminingForfeitureRate Share-based Compensation Arrangement by Share-based Payment Award, Period for Determining Forfeiture Rate The period used for determining the forfeiture rate for share based compensation awards. Unrealized Gain (Loss) on Investments [Table Text Block] Schedule of Intangible Assets and Goodwill [Table Text Block] Time deposits Available for sale securities in a continuous unrealized loss position, less than 12 months, fair value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block] Available for sale securities in a continuous unrealized loss position, 12 months or more, fair value Available for sale securities in a continuous unrealized loss position, fair value Net increase (decrease) in time deposits us-gaap_ContractuallySpecifiedServicingFeesAmount Contractually Specified Servicing Fees, Amount Fair Value Measurements, Nonrecurring [Table Text Block] Net increase in demand, money market and savings deposits Unrealized gain (loss) on securities, pre-tax Deposits Contractual Interest Rate Reduction and Extended Maturity [Member] Loan modification for a reduction of contractual interest rate and an extension of the term of a loan in which it must be paid. Cash flows from financing activities Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Interest Rate Lock Commitments [Member] us-gaap_StockholdersEquity Total Shareholders’ Equity Balance Balance Class of Stock [Axis] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax Unrealized Losses Investment securities available for sale, gross unrealized gains Amortized Cost Total, available for sale, amortized cost After 1 year to 5 years, available for sale, amortized cost After 5 years to 10 years, available for sale, amortized cost After 10 years, available for sale, amortized cost