Document And Entity Information
Dividend yield
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate
Note To Financial Statement Details Textual
Significant Accounting Policies
Share-Based Payment Arrangement, Option, Exercise Price Range [Table Text Block]
Note 2 - Summary of Significant Accounting Policies
U.S. federal statutory tax rate
Note 3 - Prepaid Expenses and Other Current Assets
Risk-free interest rates
Note 4 - Real Property and Other Income, Expense
Note 5 - Property and Equipment
Forfeiture rate
Note 6 - Intangible Assets
Note 7 - Stockholders' Equity and Stock-based Compensation
Note 9 - Income Taxes
Note 13 - Warrant Dividend Distribution
Income Tax Disclosure [Text Block]
Note 2 - Summary of Significant Accounting Policies - Quantitative Information of Warrants (Details)
Note 2 - Summary of Significant Accounting Policies - Summary of CODM Segments (Details)
us-gaap_SignificantSupplyCommitmentRemainingMinimumAmountCommitted
Supply Commitment, Remaining Minimum Amount Committed
Note 2 - Summary of Significant Accounting Policies - Calculation of Net Loss Per Share (Details)
Volatility
Note 3 - Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Details)
Note 4 - Real Property and Other Income, Expense - Components of Other Income, Net (Details)
us-gaap_LiabilitiesCurrent
Total current liabilities
Note 4 - Real Property and Other Income, Expense - Schedule of Gross Rental Income under Third-party Leases (Details)
Supply Commitment [Axis]
Note 5 - Property and Equipment - Components of Property and Equipment (Details)
Supply Commitment Arrangement [Domain]
Note 6 - Intangible Assets - Components of Intangible Assets (Details)
Expected life of option (in years) (Year)
Note 6 - Intangible Assets - Amortization Expense for Finite-lived Intangible Assets (Details)
Other current liabilities
Note 7 - Stockholders' Equity and Stock-based Compensation - Stock Option Activity (Details)
Note 7 - Stockholders' Equity and Stock-based Compensation - Schedule of Stock Options by Exercise Price (Details)
Note 7 - Stockholders' Equity and Stock-based Compensation - Stock Option Valuation Assumptions (Details)
Note 7 - Stockholders' Equity and Stock-based Compensation - Stock Option and Performance Award Activity (Details)
Interest receivable
Note 7 - Stockholders' Equity and Stock-based Compensation - Stock-based Compensation Expense (Details)
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
Note 9 - Income Taxes - Schedule of Effective Income Tax Reconciliation (Details)
Note 9 - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details)
Note 9 - Income Taxes - Schedule of Unrecognized Tax Benefits (Details)
Note 13 - Warrant Dividend Distribution - Changes in Warrants Outstanding and Warrant Liability (Details)
Notes To Financial Statements
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
Notes To Financial Statements [Abstract]
Share-Based Payment Arrangement, Activity [Table Text Block]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Forfeited/canceled, awards (in shares)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Outstanding, awards (in shares)
Outstanding, awards (in shares)
Granted, awards (in shares)
Vested, awards (in shares)
Vested and expected to vest at December 31, 2022, weighted average contractual term (Year)
Vested and expected to vest at December 31, 2025 (in shares)
Vested and expected to vest at December 31, 2022, weighted average exercise price (in dollars per share)
Vested and expected to vest at December 31, 2022, aggregate intrinsic value
Exercisable at December 31, 2022, weighted average exercise price (in dollars per share)
Exercisable at December 31, 2022, weighted average contractual term (Year)
Exercisable at December 31, 2022, aggregate intrinsic value
Exercisable at December 31, 2025 (in shares)
Outstanding as of December 31, 2022, weighted average contractual term (Year)
Outstanding as of December 31, 2022, aggregate intrinsic value
Weighted average fair value of stock options granted (in dollars per share)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Outstanding, options, weighted average exercise price (in dollars per share)
Outstanding, options, weighted average exercise price (in dollars per share)
Accounts payable and other accrued expenses
Options forfeited/canceled, weighted average exercise price (in dollars per share)
us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent
Accrual for Taxes Other than Income Taxes, Current
Options granted, weighted average exercise price (in dollars per share)
Options exercised, weighted average exercise price (in dollars per share)
Accrued compensation and benefits
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Outstanding, options (in shares)
Outstanding, options (in shares)
us-gaap_PolicyTextBlockAbstract
Accounting Policies
us-gaap_LossContingencyNewClaimsFiledNumber
Loss Contingency, New Claims Filed, Number
Former Chief Medical Officer [Member]
Represents the former Chief Medical Officer.
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchases of property and equipment
flna_ConsultingAgreementFixedFee
Consulting Agreement, Fixed Fee
The fixed fee amount for the consulting agreement.
Non-cash financing activities
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)
Grantee Status [Domain]
Grantee Status [Axis]
Leases, Acquired-in-Place [Member]
Current liabilities:
us-gaap_LossContingencyAccrualProvision
Loss Contingency Accrual, Provision
us-gaap_Assets
Total assets
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]
Plan Name [Axis]
Shareholders' Equity and Share-Based Payments [Text Block]
Plan Name [Domain]
Compensation and Employee Benefit Plans [Text Block]
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)
us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted
Adjusted numerator, diluted
us-gaap_DilutiveSecurities
Adjustment for change in fair value of warrant liabilities
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
us-gaap_PreferredStockDividendsAndOtherAdjustments
Adjustment for change in fair value of warrant liabilities
Award Type [Domain]
Derecognition of warrant liabilities upon exercise of warrants
Amount of increase in additional paid in capital (APIC) resulting from derecognition of warrant liabilities upon exercise of warrants.
Effective Income Tax Rate Reconciliation [Table]
Award Type [Axis]
Net loss
Net loss
Net loss
Net loss
us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Accumulated amortization
us-gaap_FiniteLivedIntangibleAssetsNet
Total amortization
Gross intangible assets
Performance Shares [Member]
Share-Based Payment Arrangement, Option [Member]
Warrant [Member]
Antidilutive Securities [Axis]
Antidilutive Securities, Name [Domain]
Loss Contingencies [Table]
us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Accumulated depreciation
Property and equipment, net
Property and equipment, net
Contingencies Disclosure [Text Block]
Gross property and equipment
flna_ExerciseOfWarrantsResultingInDecreaseInWarrantLiability
Warrants exercised
Amount of decrease in warrant liability from exercise of warrants.
Warrant Dividend Distribution [Text Block]
The entire disclosure of warrant dividend distribution.
Issuance of warrants resulting in recognition of warrant liabilities
Amount of issuance of warrants resulting in recognition of warrant liabilities.
Cash flows from investing activities:
us-gaap_IncreaseDecreaseInOtherOperatingLiabilities
Other liabilities
us-gaap_RelatedPartyTransactionAmountsOfTransaction
Related Party Transaction, Amounts of Transaction
us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities
Accrued compensation and benefits
us-gaap_IncomeTaxExpenseBenefit
Effective income tax rate
us-gaap_IncreaseDecreaseInAccountsPayable
Accounts payable and other accrued expenses
us-gaap_OperatingExpenses
Total operating expenses
General and administrative
us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay
Cash and cash equivalents
Total stock-based compensation expense
Share-Based Payment Arrangement, Expense
Common stock issued pursuant to warrant exercises, net of exercise costs (in shares)
Number of shares of stock issued attributable to warrant exercises.
Common stock issued pursuant to warrant exercises, net of exercise costs
Value of shares of stock issued attributable to exercises of warrants.
us-gaap_LegalFees
Legal Fees
Real Estate Owned [Text Block]
Amendment Flag
City Area Code
Use of Estimates, Policy [Policy Text Block]
New Accounting Pronouncements, Policy [Policy Text Block]
us-gaap_SharesOutstanding
Balance (in shares)
Balance (in shares)
Common stock, shares outstanding (in shares)
Preferred stock, shares outstanding (in shares)
us-gaap_NetRentableArea
Net Rentable Area (Square Foot)
Tax attribute expiration, percent
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax attribute expiration.
Current Fiscal Year End Date
CODM Monitoring [Member]
Relating to CODM monitoring.
License Agreement [Member]
Relating to a license agreement.
Yale University [Member]
Relating to Yale University.
us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets
Prepaid expenses and other current assets
Document Fiscal Period Focus
Document Fiscal Year Focus
Document Period End Date
Entity File Number
Entity Emerging Growth Company
Document Type
Entity Small Business
Entity Shell Company
Document Information [Line Items]
Document Information [Table]
Range One [Member]
Relating to range one.
flna_StockOptionsExercisedNetSettledSatisfactionOfExercisePrice
Stock Options Exercised Net Settled Satisfaction Of Exercise Price (in shares)
Represents the number of stock options exercised net settled in satisfaction of the exercise price.
Entity Public Float
us-gaap_SeveranceCosts1
Severance Costs
Entity Filer Category
Entity Current Reporting Status
Entity Voluntary Filers
Entity Well-known Seasoned Issuer
Indefinite Life Carryforwards [Member]
Relating to indefinite life tax carryforwards.
Carryforward Subject to Expiration [Member]
Relating to tax carryforwards subject to expiration.
Range Three [Member]
Relating to range three.
Range Two [Member]
Relating to range two.
us-gaap_LessorOperatingLeasePaymentsToBeReceived
Total gross rental income
Range Five [Member]
Relating to range five.
Range Four [Member]
Relating to range four.
Award Timing MNPI Disclosure [Text Block]
us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued
Issuance of warrants
Leases And Commitments Disclosure [Text Block]
The entire disclosure regarding leases and commitments.
Change in fair value of warrant liabilities
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in fair value of warrant liabilties.
Section 162(m) limitation
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to section 162(m) limitation.
Capitalized research and development expenses
Amount before allocation of valuation allowances of deferred tax asset attributable to capitalized research and development expenses.
ecd_AwardTmgMnpiCnsdrdFlag
Award Timing MNPI Considered [Flag]
Tax attribute expiration
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax attributable expiration.
Entity Tax Identification Number
Real Estate Property, Ownership [Table]
Entity Central Index Key
Insider Trading Policies and Procedures [Line Items]
2026
Entity Registrant Name
2027
Stock options for employees
ecd_InsiderTrdPoliciesProcAdoptedFlag
Insider Trading Policies and Procedures Adopted [Flag]
2028
2029
Entity [Domain]
Legal Entity [Axis]
Lessor, Operating Lease, Payment to be Received, Maturity [Table Text Block]
Entity Address, Address Line One
Amortization of intangible assets
Amortization of Intangible Assets
ecd_NonRule10b51ArrTrmntdFlag
Non-Rule 10b5-1 Arrangement Terminated [Flag]
Entity Address, City or Town
ecd_Rule10b51ArrTrmntdFlag
Rule 10b5-1 Arrangement Terminated [Flag]
ecd_Rule10b51ArrAdoptedFlag
Rule 10b5-1 Arrangement Adopted [Flag]
Entity Address, Postal Zip Code
Entity Address, State or Province
ecd_NonRule10b51ArrAdoptedFlag
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Material Terms of Trading Arrangement [Text Block]
Entity Common Stock, Shares Outstanding
Trading Arrangements, by Individual [Table]
Trading Symbol
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
Local Phone Number
Issuance of common stock pursuant to exercise of stock options (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)
Options exercised (in shares)
us-gaap_TableTextBlock
Notes Tables
Issuance of common stock pursuant to exercise of stock options
Related and Nonrelated Parties [Axis]
Related and Nonrelated Parties [Domain]
Options granted (in shares)
Warrant measurement
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
Options forfeited/canceled (in shares)
us-gaap_StockIssuedDuringPeriodSharesNewIssues
Stock Issued During Period, Shares, New Issues (in shares)
Other segment items
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and stockholders' equity
Accumulated deficit
Retained Earnings (Accumulated Deficit)
Research and development
Research and development
Federal Income Tax Note [Table]
Measurement Input, Share Price [Member]
Measurement Input, Price Volatility [Member]
Changes in operating assets and liabilities:
Measurement Input, Risk Free Interest Rate [Member]
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
Subsequent Event [Member]
Measurement Input, Expected Dividend Rate [Member]
Measurement Input, Expected Term [Member]
Subsequent Event Type [Axis]
Measurement Input, Exercise Price [Member]
Defined Benefit Plan [Table]
Subsequent Event Type [Domain]
Measurement Input, Conversion Price [Member]
flna_WarrantRedemptionPrice
Warrant Redemption Price (in dollars per share)
Price of warrants if they are redeemed.
Measurement Input Type [Axis]
Measurement Input Type [Domain]
Fair Value Measurement, Policy [Policy Text Block]
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
2027
Fair Value of Financial Instruments, Policy [Policy Text Block]
flna_NumberOfFormerEmployees
Number of Former Employees
Represents the number of former employees.
flna_RedemptionPercentageOfWarrants
Redemption Percentage of Warrants
The Percent of the cost for redemption of warrants.
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
2028
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
2029
Former Senior Officer [Member]
Represents the former senior officers.
flna_CommissionPercentageOfGrossProceeds
Commission Percentage of Gross Proceeds
Represents the percentage of commission required to be paid from gross proceeds.
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]
Segment Reporting, Policy [Policy Text Block]
flna_GrossProceedsFromIssuanceOfWarrants
Gross Proceeds From Issuance of Warrants
Gross proceeds received from the issuance and sale of warrants.
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
2026
Former Senior Vice President [Member]
Represents the former vice president.
Share-Based Payment Arrangement, Employee [Member]
Gain from change in fair value of warrant liabilities
Gain from change in fair value of warrant liabilities
Gain from change in fair value of warrant liabilities
us-gaap_ShareBasedCompensation
Stock-based compensation
flna_ClassOfWarrantsOrRightsCommonStockWarrantsRedeemed
Redemption of common stock warrants (in shares)
Represents the warrants redeemed common stock warrants.
Share-Based Payment Arrangement, Nonemployee [Member]
Earnings Per Share, Policy [Policy Text Block]
Related Party Transaction [Policy Text Block]
Policy describing the related party transactions.
Intangible Asset, Finite-Lived [Table]
Income Tax, Policy [Policy Text Block]
flna_ClassOfWarrantOrRightFairValueOfCommonStockWarrantsPerWarrant
Class of Warrant or Right, Fair Value of Common Stock Warrants per Warrant (in dollars per share)
Represents the fair value of common stock warrants per warrant.
flna_ClassOfWarrantOrRightRedemptionPricePerShare
Class of Warrant or Right, Redemption Price per Share (in dollars per share)
Represents the redemption price per share of warrants or rights.
Anti-SLAPP Lawsuit [Member]
Represents the anti-SLAAP lawsuit
Accrued development expense
Amount of accrued development expense, classified as current.
Schedule of Finite-Lived Intangible Assets [Table Text Block]
Research and Development Expense, Policy [Policy Text Block]
Depreciation
Depreciation
flna_ConsultingAgreementTerm
Consulting Agreement, Term
The consulting agreement term.
Intangible Assets Disclosure [Text Block]
Simufilam Active Ingredient [Member]
Represents the simufilam active ingredient.
us-gaap_AssetsCurrent
Total current assets
Share-Based Payment Arrangement [Policy Text Block]
Compensation Related Costs, Policy [Policy Text Block]
Interest income
Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]
Common stock, $0.001 par value; 120,000,000 shares authorized; 48,307,896 and 48,203,179 shares issued and outstanding at December 31, 2025 and 2024, respectively
Adjustments to reconcile net loss to net cash used in operating activities:
Common stock, shares authorized (in shares)
Common stock, shares issued (in shares)
Common stock, par value (in dollars per share)
Common Stock, Par or Stated Value Per Share (in dollars per share)
us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount
us-gaap_DeferredTaxAssetsValuationAllowance
Valuation allowance
Statistical Measurement [Domain]
Maximum [Member]
Commitments and Contingencies, Policy [Policy Text Block]
Minimum [Member]
Other
us-gaap_OtherAssetsCurrent
us-gaap_DeferredTaxAssetsNet
Net deferred tax assets
Statistical Measurement [Axis]
Litigation Case [Axis]
Litigation Case [Domain]
Preferred stock, $0.001 par value; 10,000,000 shares authorized, none issued and outstanding
us-gaap_DeferredTaxAssetsLiabilitiesNet
Net deferred tax asset (liability)
Preferred stock, shares issued (in shares)
us-gaap_DeferredTaxAssetsOther
Other
Geographical [Axis]
Property, Plant and Equipment Disclosure [Text Block]
Geographical [Domain]
Property, Plant and Equipment [Table Text Block]
us-gaap_DeferredTaxAssetsGross
Total deferred tax assets
Preferred stock, shares authorized (in shares)
us-gaap_DeferredIncomeTaxLiabilities
Total deferred tax liabilities
Preferred stock, par value (in dollars per share)
Prepaid insurance
flna_IncreaseDecreaseInDevelopmentExpense
Accrued development expense
Amount of increase (decrease) in development expense.
flna_IncreaseDecreaseInOperatingLeaseRightOfUseAssetsAndLiabilitiesNet
Operating lease right-of-use assets and liabilities
Amount of increase (decrease) in operating lease right of use assets and liabilities, net.
us-gaap_ProceedsFromInsuranceSettlementOperatingActivities
Proceeds from Insurance Settlement, Operating Activities
Prepaid Expenses and Other Current Assets [Text Bock]
The entire disclosure of prepaid expenses and other current assets.
Legal reserves
us-gaap_PropertyPlantAndEquipmentUsefulLife
Property, Plant and Equipment, Useful Life (Year)
Warrants to Purchase Common Stock [Member]
Represents the warrants used to purchase common stock.
flna_ClassOfWarrantOrRightIssuedDuringPeriod
Class Of Warrant Or Right Issued During Period (in shares)
The number of warrants or rights issued during period.
Construction in Progress [Member]
Cash flows from operating activities:
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Balance, liability
Warrants and Rights Outstanding
Balance, liability
Balance, liability
Statement [Line Items]
flna_ClassOfWarrantOrRightExercisedDuringPeriod
Class of Warrant or Right, Exercised During Period (in shares)
Warrants exercised (in shares)
Represents the warrants or rights exercised during the period.
TEXAS
us-gaap_NumberOfOperatingSegments
Number of Operating Segments
flna_PercentageOfOccupancy
Percentage of Occupancy
Percentage of occupancy.
Furniture and Fixtures [Member]
us-gaap_NumberOfReportableSegments
Number of Reportable Segments
flna_ProceedsFromWarrantsExercisedThatObligatedToPayCommission
Proceeds From Warrants Exercised That Obligated to Pay Commission
Dollar amount required to be paid for commission from warrants exercised during the period.
us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
Share-based compensation
Additional paid-in capital
Property, Plant and Equipment, Other Types [Member]
Building [Member]
Building Improvements [Member]
Stockholders' equity:
Land [Member]
Leasehold Improvements [Member]
Property, Plant and Equipment, Policy [Policy Text Block]
us-gaap_OtherNonoperatingExpense
Property operating expenses
Property, Plant and Equipment [Table]
Partners' Capital, Managing Member or General Partner, Incentive Distribution [Table]
Other income (loss), net
Other income (loss), net
Long-Lived Tangible Asset [Axis]
Long-Lived Tangible Asset [Domain]
Net operating loss carryforwards
Research and development credit carryforwards
Lease revenue
Current assets:
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
Contract research organization and other deposits
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash (used in) / provided by financing activities
us-gaap_Liabilities
Total liabilities
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
Net increase (decrease) in cash and cash equivalents
Commitments and contingencies (Notes 10, 11 and 12)
Sale of Stock [Axis]
Sale of Stock [Domain]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]
us-gaap_OperatingIncomeLoss
Operating loss
us-gaap_NetCashProvidedByUsedInOperatingActivities
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation
Net cash used in operating activities
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash used in investing activities
Prepaid expenses and other current assets
Total prepaid expenses and other current assets
us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets
Intangibles
Counterparty Name [Axis]
Counterparty Name [Domain]
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]
Derivatives, Policy [Policy Text Block]
us-gaap_LitigationReserve
Estimated Litigation Liability
Schedule of Other Nonoperating Income (Expense) [Table Text Block]
Cash Incentive Bonus Plan [Text Block]
The entire disclosure for the cash incentive bonus plan.
us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Violations of Federal Securities Laws [Member]
Represents the violations of federal securities laws.
flna_PerformancePlanValuationMilestoneAmount
Performance Plan, Valuation Milestone Amount
Amount of valuation milestone for performance plan.
us-gaap_PaymentsOfStockIssuanceCosts
Payments of Stock Issuance Costs
2025 ATM offering program costs
flna_CashBonusIncentiveIncrementalAmounts
Cash Bonus Incentive, Incremental Amounts
The number of incremental amounts for cash bonus incentive.
flna_PerformancePlanMinimumNumberOfDaysValuationMilestoneMustBeAchievedAndMaintained
Performance Plan, Minimum Number of Days Valuation Milestone Must be Achieved and Maintained (Day)
The minimum number of days valuation milestone must be achieved and maintained in performance plan.
Cash Incentive Bonus Plan [Member]
Represents the cash incentive bonus plan.
Shareholder Derivative Actions, Texas Court [Member]
Represents shareholder derivative actions in Texas Court
Shareholder Derivative Actions [Member]
Represents shareholder derivative actions.
Shareholder Derivative Actions, Delaware Court [Member]
Represents shareholder derivative actions in Delaware court.
Shareholder Derivative Actions, Texas State Court Member
Represents shareholder derivative actions in Texas State Court.
flna_EquityOfferingPercentageOfCommission
Equity Offering, Percentage of Commission
Percentage of commission in equity offering.
flna_EquityOfferingMaximumAmount
Equity Offering, Maximum Amount
The maximum amount to be issued in the equity offering.
flna_PaymentsForCashIncentiveBonus
Payments for Cash Incentive Bonus
Amount of payments for cash incentive bonus.
flna_CashIncentiveBonusAward
Cash Incentive Bonus Award
Amount of cash incentive bonus award.
Leasing Commissions and Other [Member]
Represents leasing commissions and other.
The 2018 Equity Incentive Plan [Member]
Represents the 2018 Equity Incentive Plan.
Stock Options Net Settled in Satisfaction of the Exercise Price [Member]
Represents stock options were net settled in satisfaction of the exercise price.
us-gaap_ProceedsFromIssuanceOfWarrants
Proceeds from Issuance of Warrants
Proceeds from exercise of common stock warrants, net of exercise costs
Retained Earnings [Member]
Proceeds from issuance of common stock upon exercise of stock options
Proceeds from Stock Options Exercised
Title and Position [Domain]
Title and Position [Axis]
flna_PaymentsOfWarrantExerciseCosts
Payments of Warrant Exercise Costs
Represents the amount of warrant exercise costs during the period.
Additional Paid-in Capital [Member]
Common Stock [Member]
Derecognition of warrant liabilities upon exercise of warrants
flna_DerecognitionOfWarrantLiabilitiesThroughExercises
Represents the cash flow effect of derecognition of warrant liabilities through exercises.
Equity Components [Axis]
Equity Component [Domain]
us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)
Class of Warrant or Right [Axis]
Class of Warrant or Right [Domain]
us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)
Balance, shares (in shares)
Class of Warrant or Right, Outstanding (in shares)
Balance, shares (in shares)
Balance, shares (in shares)
Class of Warrant or Right [Table]
us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)
ICFR Auditor Attestation Flag
Income Tax Jurisdiction [Axis]
Income Tax Jurisdiction [Domain]
Domestic Tax Jurisdiction [Member]
Document Annual Report
Cash and Cash Equivalents, Policy [Policy Text Block]
Entity Incorporation, State or Country Code
us-gaap_UnrecognizedTaxBenefits
Unrecognized Tax Benefits
Beginning balance
Ending balance
General and Administrative Expense [Member]
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]
us-gaap_OpenTaxYear
Open Tax Year
Document Transition Report
Document Financial Statement Error Correction [Flag]
us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations
Expired research and development tax credits
Entity Interactive Data Current
Security Exchange Name
Additions based on tax positions related to the current year
Title of 12(b) Security
Research and Development Expense [Member]
Statement of Income Location, Balance [Axis]
Statement of Income Location, Balance [Domain]
Office Building [Member]
Real Estate, Type of Property [Axis]
Tax Period [Domain]
Real Estate [Domain]
Auditor Name
Tax Period [Axis]
Auditor Firm ID
Auditor Location
Segments [Axis]
Segments [Domain]
us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment
Dilutive effect of common stock warrants (in shares)
us-gaap_TaxCreditCarryforwardAmount
Tax Credit Carryforward, Amount
flna_PolicyTable
Research Tax Credit Carryforward [Member]
us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)
Shares used in computing net loss per share, diluted (in shares)
Weighted average dilutive common shares (in shares)
Tax Credit Carryforward [Axis]
Tax Credit Carryforward, Name [Domain]
us-gaap_OperatingLossCarryforwards
Operating Loss Carryforwards
Statement [Table]
Statement of Financial Position [Abstract]
Net loss per share, diluted (in dollars per share)
Net loss per share, diluted (in dollars per share)
Shares used in computing net loss per share, basic (in shares)
Weighted average common shares outstanding (in shares)
Other, percent
us-gaap_EffectiveIncomeTaxRateContinuingOperations
Effective income tax rate, percent
Net loss per share, basic (in dollars per share)
Net loss per share, basic (in dollars per share)
Change in valuation allowance, percent
Statement of Cash Flows [Abstract]
Statement of Stockholders' Equity [Abstract]
Income Statement [Abstract]
Change in fair value of warrant liabilities, percent
Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to the change in fair value of warrant liabilities.
Uncertain tax positions, percent
At-the-market 2025 Offering Program [Member]
Represents information pertaining to the 2025 ATM offering program.
SEC settlement payment, percent
Former President and Chief Executive Officer [Member]
The former President and Chief Executive Officer.
us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated
Restructuring and Related Cost, Number of Positions Eliminated
Workforce Reduction [Member]
The workforce reduction.
us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent
Restructuring and Related Cost, Number of Positions Eliminated, Period Percent
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]
us-gaap_RestructuringAndRelatedCostIncurredCost
Restructuring and Related Cost, Incurred Cost
flna_FinitelivedIntangibleAssetExpectedAmortizationYearFiveAndThereafter
2030 and beyond
Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in fifth fiscal year and thereafter following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
us-gaap_OtherCommitment
Other Commitment
Stock compensation, percent
Accounting Standards Update and Change in Accounting Principle [Table]
Restructuring Plan [Axis]
Restructuring Plan [Domain]
Type of Restructuring [Domain]
Section 162(m) limitation, percent
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to section 162(m) limitation.
Employee Severance [Member]
Restructuring and Related Activities Disclosure [Text Block]
State tax, net of federal benefit, percent
Other Commitments [Axis]
Restructuring Cost [Table]
Restructuring Type [Axis]
Other Commitments [Domain]
Research and development credits, percent
Other
Cash flows from financing activities:
U.S. federal statutory tax rate, percent
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent
Other non-current liabilities
Change in valuation allowance
2030 and beyond
Amount of lease payment to be received by lessor for operating lease in fifth fiscal year and thereafter following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).
SEC settlement payment
Uncertain tax positions
flna_PerformancePlanMergerConsiderationMilestone
Performance Plan, Merger Consideration Milestone
Amount of merger consideration milestone under performance plan.
flna_ValuationMilestonesAcheieved
Valuation Milestones Achieved
Amount of valuation milestone achieved.
Offsetting Assets [Table]
us-gaap_StockholdersEquity
Total stockholders' equity
Balance
Balance
Class of Stock [Axis]
us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost
Stock compensation
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Options outstanding, weighted average exercise price (in dollars per share)
us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1
Options outstanding, weighted average contractual life (Year)
us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2
Options exercisable (in shares)
us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions
Options exercisable, weighted average exercise price (in dollars per share)
us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1
Options, exercise price, upper limit (in dollars per share)
Options outstanding (in shares)
us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions
State tax, net of federal benefit
Exercise Price Range [Axis]
Exercise Price Range [Domain]
us-gaap_IncomeTaxReconciliationTaxCreditsResearch
Research and development credits
Options, exercise price, lower limit (in dollars per share)