Document And Entity Information us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Note To Financial Statement Details Textual Significant Accounting Policies us-gaap_IncomeTaxExpenseBenefit Income Tax Expense (Benefit) Note 3 - Fair Value Measurement ecd_NonRule10b51ArrTrmntdFlag Non-Rule 10b5-1 Arrangement Terminated [Flag] Note 4 - Property and Equipment, Net ecd_NonRule10b51ArrAdoptedFlag Non-Rule 10b5-1 Arrangement Adopted [Flag] Note 5 - Leases Trading Arrangements, by Individual [Table] Note 6 - Accrued Expenses and Other Current Liabilities us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross Restricted stock units vested and issued (in shares) Material Terms of Trading Arrangement [Text Block] Note 7 - Stockholders' Equity Note 8 - Share-based Compensation Note 9 - Net Loss Per Share Note 3 - Fair Value Measurements - Fair Value of Assets Measured on a Recurring Basis (Details) Note 4 - Property and Equipment, Net - Summary of Property and Equipment, Net (Details) Note 5 - Leases - Future Minimum Lease Payments Under Operating Lease (Details) Note 6 - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) Note 7 - Stockholders' Equity - Warrants (Details) Note 7 - Stockholders' Equity - Schedule of Stockholders Equity (Details) Note 8 - Share-based Compensation - Share-based Compensation Expense (Details) Note 8 - Share-based Compensation - Share-based Compensation Expense 2 (Details) Note 8 - Share-based Compensation - Stock Option Activity (Details) us-gaap_IncreaseDecreaseInAccountsReceivable Accounts payable Note 8 - Share-based Compensation - Summary of Non-vested RSUs (Details) Note 9 - Net Loss Per Share - Anti-dilutive Securities (Details) Notes To Financial Statements Notes To Financial Statements [Abstract] Operating activities: Investing activities: us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash used in operating activities Financing activities: Business Description and Basis of Presentation [Text Block] us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash provided by financing activities Stock options forfeited, weighted average exercise price (in dollars per share) Warrants To Purchase Common Stock [Member] Represents warrants to purchase common stock. Stock options granted, weighted average exercise price (in dollars per share) Accounting Policies [Abstract] us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent Accounts Receivable, Allowance for Credit Loss, Current Leasehold Improvements [Member] Income Statement [Abstract] us-gaap_SharesOutstanding Balance (in shares) Balance (in shares) Net loss Net loss Net loss Award Type [Axis] Preferred stock, $0.001 par value, 25,000,000 shares authorized and no shares issued and outstanding as of March 31, 2026 and December 31, 2025 us-gaap_Liabilities Total liabilities Associated issuance costs Issuance costs us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders’ equity (deficit) Costs and expenses: us-gaap_AllocatedShareBasedCompensationExpense Total share-based compensation Cash and Cash Equivalents [Axis] Title and Position [Axis] us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other current assets Accrued salaries and employee benefits Carrying value as of the balance sheet date of the obligations incurred through that date and payable for employees' services provided and employee benefits (due within one year or within the normal operating cycle if longer). June 2025 Financing [Member] Represents the June 2025 financing. Selling, general and administrative us-gaap_ShareBasedCompensation Share-based compensation us-gaap_CostsAndExpenses Total costs and expenses ATM [Member] Represents ATM agreement. Lessee, Lease, Description [Table] Income Tax Disclosure [Text Block] Gross proceeds Share-Based Payment Arrangement [Text Block] Location, Statement of Income, Balance [Axis] Accounts payable us-gaap_IncreaseDecreaseInAccountsPayable Preferred Stock, Shares Issued (in shares) Accounting Standards Update and Change in Accounting Principle [Table] Preferred Stock, Shares Outstanding (in shares) us-gaap_PreferredStockSharesAuthorized Preferred Stock, Shares Authorized (in shares) Employees, Non-employees and Non-employee Directors [Member] Represents Employees, Non-employees and Non-employee Directors us-gaap_PreferredStockParOrStatedValuePerShare Preferred Stock, Par or Stated Value Per Share (in dollars per share) us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net change in cash and cash equivalents us-gaap_CashAndCashEquivalentsFairValueDisclosure Cash in savings account New Accounting Pronouncements, Policy [Policy Text Block] us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period bcda_PolicyTable Concentration Risk, Credit Risk, Policy [Policy Text Block] Antidilutive Securities, Name [Domain] bcda_ClassOfWarrantOrRightOutstandingWeightedAverageRemainingContractualTerm Class of Warrant or Right, Outstanding, Weighted-Average Remaining Contractual Term (Year) Weighted-average contractual term remaining for class or warrants or rights outstanding. Statement [Table] Reclassification, Comparability Adjustment [Policy Text Block] us-gaap_OperatingLeasePayments Operating Lease, Payments Fair Value Hierarchy and NAV [Domain] Measurement Frequency [Domain] Warrants exercised, exercise price (in dollars per share) Weighted average exercise price per share or per unit of warrants or rights issued during the period. Other income (expense): Statement of Financial Position [Abstract] Total other income, net us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber Balance, Number of shares (in shares) Balance, Number of shares (in shares) us-gaap_DeferredTaxLiabilities Deferred Tax Liabilities, Net us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue Balance, weighted average grant date fair value per share (in dollars per share) RSUs granted, Number of shares (in shares) Supplemental disclosure of noncash investing and financing activities: RSUs granted, weighted average grant date fair value per share (in dollars per share) Schedule of Activity Under Sales Agreement [Table Text Block] The schedule of activity under the sales agreement. Accrued expenses and other current liabilities Total Amount of accrued liabilities and liabilities classified as other, due within one year or the normal operating cycle, if longer. Fair Value, Recurring [Member] RSUs released, weighted average grant date fair value per share (in dollars per share) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod RSUs released, Number of shares (in shares) Other assets us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total undiscounted lease payments Warrant [Member] us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent Operating Lease, Weighted Average Discount Rate, Percent dei_DocumentType Document Type Schedule of Accrued Liabilities and Other Current Liabilities [Table Text Block] Tabular disclosure of the components of accrued liabilities and other current liabilities. Demand Deposits [Member] Accrued Liabilities and Other Current Liabilities Disclosure [Text Block] The entire disclosure for accrued liabilities and other current liabilities at the end of the reporting period. Document Information [Line Items] Document Quarterly Report us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths 2027 Grant liability Amount of obligations incurred for grants, payable within one year or the normal operating cycle, if longer. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod Stock options forfeited, options (in shares) us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1 Operating Lease, Weighted Average Remaining Lease Term Document Information [Table] us-gaap_OperatingLeaseExpense Operating Lease, Expense us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Stock options to purchase common stock (in shares) Antidilutive Securities [Axis] us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear 2026 Stock options exercisable, options (in shares) dei_EntityInteractiveDataCurrent Entity Interactive Data Current Stock options exercisable, weighted average exercise price, ending of period (in dollars per share) Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Measurement Frequency [Axis] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Stock options outstanding, options (in shares) Outstanding, March 31, 2026 (in shares) Document Transition Report us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding Weighted-average shares used in computing net loss per share, diluted (in shares) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice Balance, weighted average exercise price, beginning of period (in dollars per share) Outstanding, March 31, 2026 (in dollars per share) Statement [Line Items] Fair Value Hierarchy and NAV [Axis] Stock options outstanding, aggregate intrinsic value Common Stock, Shares, Issued (in shares) April 2025 Financing [Member] Represents April 2025 financing. Common Stock, Shares, Outstanding (in shares) Award Type [Domain] us-gaap_CommonStockSharesAuthorized Common Stock, Shares Authorized (in shares) Customer deposits The amount of customer deposit liabilities classified as current. Weighted-average shares used in computing net loss per share, basic (in shares) Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Net loss per share, basic (in dollars per share) Unpaid issuance costs of common stock Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table] us-gaap_CommonStockValue Common stock, $0.001 par value, 50,000,000 shares authorized, 10,940,372 and 10,755,647 shares issued and outstanding as of March 31, 2026 and December 31, 2025, respectively Effective Income Tax Rate Reconciliation [Table] us-gaap_ProceedsFromIssuanceOrSaleOfEquity Proceeds from Issuance or Sale of Equity Title and Position [Domain] Proceeds from sales of common stock us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 Class of Warrant or Right, Exercise Price of Warrants or Rights Balance, exercise price (in dollars per share) Balance, exercise price (in dollars per share) Accounts payable us-gaap_PolicyTextBlockAbstract Accounting Policies us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_TableTextBlock Notes Tables Document Fiscal Period Focus Document Fiscal Year Focus Contingencies Disclosure [Text Block] Amendment Flag Common Stock [Member] bcda_SaleOfStockAvailableValue Sale of Stock, Available Value Represents value of common stock available to sale under purchase agreement at period end. bcda_StockIssuedDuringPeriodSharesWarrantsExercised Exercise of September 2025 common stock warrants (in shares) Number of new stock issued due to warrants exercised during the period. Accrued expenses dei_DocumentPeriodEndDate Document Period End Date bcda_StockIssuedDuringPeriodValueWarrantsExercised Exercise of September 2025 common stock warrants Equity impact of the value of new stock issued due to warrants exercised during the period. Property, Plant, and Equipment [Text Block] Long-Lived Asset, Class [Domain] Stock options granted, options (in shares) Legal Entity [Axis] Significant Accounting Policies [Text Block] Reduction in the carrying amount of right-of-use assets Less imputed interest dei_EntityFileNumber Entity File Number Operating lease liability - noncurrent Stock options outstanding, weighted average remaining contractual term (Year) Entity Tax Identification Number Total operating lease liabilities Operating lease liability - current Entity [Domain] Entity Central Index Key dei_EntityRegistrantName Entity Registrant Name dei_EntityCurrentReportingStatus Entity Current Reporting Status Entity Incorporation, State or Country Code Current Fiscal Year End Date Stock options exercisable weighted average remaining contractual term (Year) Research and development Entity Filer Category dei_EntityShellCompany Entity Shell Company Entity Emerging Growth Company Entity Small Business us-gaap_OperatingIncomeLoss Operating loss Cash and Cash Equivalents [Domain] Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] September 2025 Warrants [Member] Represents the September 2025 warrants. dei_EntityAddressStateOrProvince Entity Address, State or Province Loss Contingencies [Table] Statement of Stockholders' Equity [Abstract] dei_EntityAddressCityOrTown Entity Address, City or Town Accumulated deficit Retained Earnings (Accumulated Deficit), Total dei_EntityAddressAddressLine1 Entity Address, Address Line One Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Statement of Cash Flows [Abstract] dei_CityAreaCode City Area Code dei_LocalPhoneNumber Local Phone Number dei_EntityAddressPostalZipCode Entity Address, Postal Zip Code Going Concern and Liquidity [Policy Text Block] Disclosure of accounting policy for reporting when there is, or is not, a substantial doubt about an entity's ability to continue as a going concern for a reasonable period of time (generally a year from the balance sheet date). Disclose: (a) pertinent conditions and events giving rise to the assessment of substantial doubt about the entity's ability to continue as a going concern for a reasonable period of time, (b) the possible effects of such conditions and events, (c) management's evaluation of the significance of those conditions and events and any mitigating factors, (d) possible discontinuance of operations, (e) management's plans (including relevant prospective financial information), and (f) information about the recoverability or classification of recorded asset amounts or the amounts or classification of liabilities. If management's plans alleviate the substantial doubt about the entity's ability to continue as a going concern, disclosure of the principal conditions and events that initially raised the substantial doubt about the entity's ability to continue as a going concern would be expected to be considered. Disclose whether operations for the current or prior years generated sufficient cash to cover current obligations, whether waivers were obtained from creditors relating to the company's default under the provisions of debt agreements and possible effects of such conditions and events, such as: whether there is a possible need to obtain additional financing (debt or equity) or to liquidate certain holdings to offset future cash flow deficiencies. Disclose appropriate parent company information when parent is dependent upon remittances from subsidiaries to satisfy its obligations. us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities Accrued expenses and other current liabilities bcda_ClassOfWarrantsOrRightsExercisedDuringPeriod Warrants exercised, warrants (in shares) Number of warrants exercised during the period. Stockholders’ equity (deficit): Title of 12(b) Security Equity Components [Axis] Security Exchange Name Trading Symbol Operating lease liability us-gaap_PaymentsOfStockIssuanceCosts Issuance costs of sale of common stock Payments of Stock Issuance Costs Class of Stock [Axis] Equity Component [Domain] Computer Equipment and Software [Member] Related to computer equipment and software. Fair Value, Inputs, Level 2 [Member] us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights Class of Warrant or Right, Number of Securities Called by Warrants or Rights Fair Value, Inputs, Level 3 [Member] Laboratory and Manufacturing Equipment [Member] Related to laboratory and manufacturing equipment. Fair Value, Inputs, Level 1 [Member] Equity [Text Block] dei_EntityCommonStockSharesOutstanding Entity Common Stock, Shares Outstanding (in shares) Additional Paid-in Capital [Member] us-gaap_ClassOfWarrantOrRightOutstanding Balance, warrants (in shares) Balance, warrants (in shares) Retained Earnings [Member] Earnings Per Share [Text Block] Management [Member] bcda_AccruedSalesCommissionCurrentPercentage Accrued Sales Commission, Current, Percentage Represents the current accrued sales commission's percentage. Property and equipment, net Property and equipment, net Property and equipment, gross Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Schedule of Share-based Compensation, Expense [Table Text Block] Tabular disclosure of the components of the allocated share-based compensation expense. Sale of Stock [Axis] Exercise of common stock warrants Stock options exercisable, aggregate intrinsic value Property, Plant, and Equipment [Table] us-gaap_CommonStockParOrStatedValuePerShare Common Stock, Par or Stated Value Per Share (in dollars per share) Furniture and Fixtures [Member] us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue Share-based compensation Basis of Accounting, Policy [Policy Text Block] Supplier Finance Program [Table] Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Long-Lived Asset, Class [Axis] Sale of Stock [Domain] Share-Based Payment Arrangement, Option, Activity [Table Text Block] us-gaap_Assets Total assets Warrant to Purchase Common Stock [Member] Represents warrant to purchase common stock trading symbol information. Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value, Total Change to Significant Accounting Policies [Policy Text Block] Disclosure of accounting policy for change to significant accounting policies. Fair Value Disclosures [Text Block] Share-Based Payment Arrangement, Option [Member] Current liabilities: us-gaap_LiabilitiesCurrent Total current liabilities bcda_CashPercentageHeldInOneFinancialInstitution Cash, Percentage Held in One Financial Institution Percentage of cash held in one financial institution. us-gaap_EarningsPerShareDiluted Net loss per share, diluted (in dollars per share) Accounts receivable, net of allowance for doubtful accounts of $0 and $0 as of March 31, 2026 and December 31, 2025, respectively Depreciation bcda_ProceedsFromIssuanceOfRestrictedStockUnitsInLieuOfCashBonus Restricted stock units issued to settle management bonus obligations The cash inflow from the issuance of restricted stock units in lieu of cash bonus. Consolidation, Policy [Policy Text Block] us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Less accumulated depreciation us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition Restricted stock units issued to settle management bonus obligations us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number (in shares) Accrued clinical trial costs Amount of obligations incurred for clinical trial costs, payable within one year or the normal operating cycle, if longer. Savings Account [Member] Represents Savings Account Additional paid-in capital us-gaap_CashUninsuredAmount Cash, Uninsured Amount us-gaap_StockholdersEquity Total stockholders’ equity (deficit) Balance Balance Prepaid expenses Use of Estimates, Policy [Policy Text Block] us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross Restricted stock units vested and issued us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition us-gaap_StockIssuedDuringPeriodValueNewIssues Sale of common stock us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Purchase of property and equipment Lessee, Operating Leases [Text Block] Stock, Class of Stock [Table] Nature of Operation, Product Information, Concentration of Risk [Table] Current assets: Operating lease right-of-use asset, net us-gaap_AssetsCurrent Total current assets Fair Value, Recurring and Nonrecurring [Table] Warrants expired, exercise price (in dollars per share) The weighted average exercise price of warrants expired during the period. ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] Property, Plant, and Equipment [Table Text Block] bcda_ClassOfWarrantOrRightExpiredDuringPeriod Warrants expired, warrants (in shares) The number of warrants or rights expired during period. ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] Commitments and Contingencies Common shares sold (in shares) Sale of common stock (in shares) Restricted Stock Units (RSUs) [Member]