Document And Entity Information Acerta Pharma BV [Member] Represents Acerta Pharma B.V. Total identifiable intangible assets acquired vcyt_CollaborativeAgreementAmount Collaborative Agreement, Amount The amount of the collaborative agreement. Note To Financial Statement Details Textual vcyt_CollaborativeAgreementContingentReceivableAmount Collaborative Agreement, Contingent Receivable Amount The amount of contingent receivable under the collaborative agreement. Significant Accounting Policies 2021 vcyt_CollaborativeAgreementFeePercentageOfCashCollections Collaborative Agreement, Fee Percentage of Cash Collections The percentage of cash collections that are to be paid under the collaborative agreement. Note 1 - Organization, Description of Business and Summary of Significant Accounting Policies 2022 Note 2 - Net Loss Per Common Share Schedule of Common Stock Capital Shares Reserved for Future Issuance [Table Text Block] The tabular disclosure for common stock capital shares reserved for future issuance. COVID 19 Pandemic [Member] Represents the COVID-19 pandemic. Note 3 - Accrued Liabilities Note 4 - Business Combination Note 5 - Fair Value Measurements Note 6 - Commitments and Contingencies Note 7 - Debt Note 8 - Stockholders' Equity Income Tax Disclosure [Text Block] Note 1 - Organization, Description of Business and Summary of Significant Accounting Policies - Schedule of Third-party Payers as a Percentage of Total (Details) Note 2 - Net Loss Per Common Share - Anti-dilutive Common Stock Equivalents Excluded from Diluted Net Loss Per Common Share (Details) Note 3 - Accrued Liabilities - Accrued Liabilities (Details) Lessee, Operating Lease, Liability, Maturity [Table Text Block] Note 4 - Business Combination - Fair Values of Assets Acquired and Liabilities Assumed (Details) Stock-based compensation Other assets Note 4 - Business Combination - Estimated Useful Life of Acquisition-related Intangibles (Details) Remainder of 2020 us-gaap_LiabilitiesCurrent Total current liabilities Note 5 - Fair Value Measurements - Fair Value Measurement Input (Details) Schedule of Debt [Table Text Block] Note 6 - Commitments and Contingencies - Future Minimum Lease Payments (Details) Note 7 - Debt - Net Debt Obligation for Borrowings (Details) Note 8 - Stockholders' Equity - Reserved Shares of Common Stock for Issuance (Details) us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Amortization of debt issuance costs Notes To Financial Statements Notes To Financial Statements [Abstract] Estimated useful life (Year) Operating expenses: us-gaap_AssetsFairValueDisclosure Assets, Fair Value Disclosure Depreciation and amortization us-gaap_AssetsCurrent Total current assets us-gaap_CashAndCashEquivalentsFairValueDisclosure Cash and Cash Equivalents, Fair Value Disclosure Stockholders' Equity Note Disclosure [Text Block] us-gaap_PaymentsToAcquireLongtermInvestments Purchase of equity securities Revaluation of acquisition-related contingent consideration Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Common stock, $0.001 par value; 125,000,000 shares authorized, 57,813,833 and 49,625,341 shares issued and outstanding as of September 30, 2020 and December 31, 2019, respectively Measurement Input Adjustments to reconcile net loss to net cash used in operating activities: Collateral for Irrevocable Standby Letter of Credit [Member] Represents collateral for irrevocable standby letter of credit. NanoString [Member] Represents NanoString. Common stock, shares authorized (in shares) Common stock, shares issued (in shares) Common stock, par value (in dollars per share) Stockholders' Equity, Policy [Policy Text Block] Revenue from Contract with Customer [Policy Text Block] Revision of Prior Period [Axis] Prosigna Product Technology [Member] Represents Prosigna product technology. Accrued liabilities Total accrued liabilities Revision of Prior Period [Domain] Prosigna Customer Relationships [Member] Represents Prosigna customer relationships. Accrued compensation expenses nCounter FLEX Dx License [Member] Represents nCounter FLEX Dx license. Revision of Prior Period, Adjustment [Member] LymphMark Product Technology [Member] Represents LymphMark product technology. Total (in shares) Statistical Measurement [Domain] Maximum [Member] Minimum [Member] Accounts payable Product and Service [Axis] Revolving Credit Facility [Member] Stock options and restricted stock units issued and outstanding (in shares) Product and Service [Domain] Statistical Measurement [Axis] Purchases of property and equipment included in accounts payable and accrued liability Credit Facility [Axis] Proceeds from disposal of property and equipment Credit Facility [Domain] Preferred stock, $0.001 par value; 5,000,000 shares authorized, no shares issued and outstanding as of September 30, 2020 and December 31, 2019 Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Accrued other Preferred stock, shares issued (in shares) Interest paid on debt us-gaap_PolicyTextBlockAbstract Accounting Policies Preferred stock, shares authorized (in shares) Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Supplies Unusual or Infrequent Item, or Both [Axis] Common stock available for issuance (in shares) Preferred stock, par value (in dollars per share) Unusual or Infrequent Item, or Both [Domain] us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Purchases of property and equipment us-gaap_ForeignCurrencyTransactionGainLossBeforeTax Effect of foreign currency on operations Fair Value Hierarchy and NAV [Domain] Customer [Axis] Fair Value, Inputs, Level 1 [Member] Customer [Domain] Fair Value Hierarchy and NAV [Axis] Current liabilities: Product [Member] Supplementary cash flow information: us-gaap_Assets Total assets us-gaap_OperatingLeaseExpense Operating Lease, Expense us-gaap_SubleaseIncome Sublease Income Operating activities Statement [Line Items] us-gaap_NumberOfOperatingSegments Number of Operating Segments Accounts receivable Revenue: Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Additional paid-in capital us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation Tax portion of vested restricted stock units Stockholders’ equity: Other income (loss), net Business Description and Basis of Presentation [Text Block] Award Type [Domain] Current assets: us-gaap_SaleOfStockPricePerShare Sale of Stock, Price Per Share (in dollars per share) Fair Value Disclosures [Text Block] Award Type [Axis] Net loss and comprehensive loss Net loss and comprehensive loss Net loss us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Finite-lived intangible assets, net us-gaap_SecurityDeposit Security Deposit us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net increase in cash, cash equivalents and restricted cash Restricted Stock Units (RSUs) [Member] Over-Allotment Option [Member] us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash provided by financing activities us-gaap_Liabilities Total liabilities Commitments and contingencies Sale of Stock [Axis] Sale of Stock [Domain] us-gaap_OperatingIncomeLoss Operating Income (Loss), Total Loss from operations us-gaap_ContractWithCustomerLiabilityRevenueRecognized Contract with Customer, Liability, Revenue Recognized Share-based Payment Arrangement, Option [Member] us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash used in operating activities us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities Prepaid expenses and other current assets Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Cost of revenue Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Counterparty Name [Axis] Counterparty Name [Domain] Write-down of excess supplies Inventory Write-down us-gaap_ContractWithCustomerLiability Contract with Customer, Liability, Total Business Combination Disclosure [Text Block] Commitments and Contingencies Disclosure [Text Block] Property and equipment, net Goodwill Goodwill, Ending Balance Investment, Policy [Policy Text Block] us-gaap_PaymentsOfStockIssuanceCosts Payments of Stock Issuance Costs Concentration Risk, Credit Risk, Policy [Policy Text Block] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation Payment of taxes on vested restricted stock units Total operating expenses Investing activities us-gaap_IncreaseDecreaseInOperatingCapital Increase (Decrease) in Operating Capital, Total us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount Equity Securities without Readily Determinable Fair Value, Amount Scenario [Domain] us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossCumulativeAmount Equity Securities without Readily Determinable Fair Value, Impairment Loss, Cumulative Amount Forecast [Member] Retained Earnings [Member] Earnings Per Share [Text Block] Total Revenue Revenue from Contract with Customer, Excluding Assessed Tax, Total Proceeds from the exercise of common stock options and employee stock purchases Proceeds from the issuance of common stock in a public offering, net Proceeds from Issuance of Common Stock Scenario [Axis] Fulfillment of Obligations Relating to Percepta v.2 Development Milestones [Member] Represents information related to fulfillment of obligations relating to Percepta v.2 development milestones. Additional Paid-in Capital [Member] Common Stock [Member] us-gaap_IncomeTaxExpenseBenefit Income Tax Expense (Benefit), Total us-gaap_IncreaseDecreaseInAccruedLiabilities Accrued liabilities Equity Components [Axis] Equity Component [Domain] us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal Gain on disposal of property and equipment Total debt obligation Long-term Debt, Total Other Noncurrent Assets [Member] us-gaap_IncreaseDecreaseInAccountsPayable Accounts payable Restricted cash Restricted Cash and Cash Equivalents, Noncurrent, Total Restricted cash General and administrative us-gaap_CashEquivalentsAtCarryingValue Cash Equivalents, at Carrying Value, Total Cash and cash equivalents Cash and cash equivalents us-gaap_RepaymentsOfLongTermDebt Repayments of Long-term Debt, Total Payment of long-term debt Balance Sheet Location [Axis] Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block] Balance Sheet Location [Domain] Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Document Quarterly Report Amendment Flag Entity Incorporation, State or Country Code Accounting Policies [Abstract] Document Transition Report City Area Code Basis of Accounting, Policy [Policy Text Block] Use of Estimates, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Schedules of Concentration of Risk, by Risk Factor [Table Text Block] Entity Interactive Data Current us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid Reclassification, Comparability Adjustment [Policy Text Block] us-gaap_SharesOutstanding Balance (in shares) Balance (in shares) Security Exchange Name Common stock, shares outstanding (in shares) us-gaap_LongTermDebtWeightedAverageInterestRateOverTime Long-term Debt, Weighted Average Interest Rate, over Time Preferred stock, shares outstanding (in shares) Title of 12(b) Security Current Fiscal Year End Date us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate Cost of Sales [Member] us-gaap_DebtInstrumentInterestRateStatedPercentage Debt Instrument, Interest Rate, Stated Percentage Other Income [Member] us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other current assets Document Fiscal Period Focus Document Fiscal Year Focus Document Period End Date Income Statement Location [Axis] Income Statement Location [Domain] Entity File Number Thereafter Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Entity Emerging Growth Company Debt principal Debt Instrument, Face Amount Document Type Measurement Input, Probability of Achievement [Member] Measurement input using probability of achievement. Entity Small Business Entity Shell Company Document Information [Line Items] Document Information [Table] Service [Member] us-gaap_AreaOfRealEstateProperty Area of Real Estate Property (Square Foot) Entity Filer Category Debt Instrument [Axis] Entity Current Reporting Status Debt Instrument, Name [Domain] London Interbank Offered Rate (LIBOR) [Member] Variable Rate [Domain] Shares used to compute net loss per common share, basic and diluted (in shares) us-gaap_AccountsReceivableNet Accounts Receivable, after Allowance for Credit Loss, Total Total common stock equivalents (in shares) Variable Rate [Axis] us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable Concentrations of credit risk Entity Tax Identification Number Net loss per common share, basic and diluted (in dollars per share) Earnings Per Share, Basic and Diluted, Total (in dollars per share) Entity Central Index Key Entity Registrant Name Stock-based compensation expense (ESPP) Entity [Domain] Asset Class [Axis] Customer Concentration Risk [Member] Legal Entity [Axis] Asset Class [Domain] Statement [Table] Entity Address, Address Line One Statement of Financial Position [Abstract] Sale of common stock, issuance costs Accounts Payable and Accrued Liabilities Disclosure [Text Block] Intangible asset amortization Entity Address, City or Town Entity Address, Postal Zip Code Business Acquisition [Axis] Entity Address, State or Province Business Acquisition, Acquiree [Domain] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Statement of Cash Flows [Abstract] Entity Common Stock, Shares Outstanding us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High Lease Contractual Term [Domain] Statement of Stockholders' Equity [Abstract] Lease Contractual Term [Axis] Income Statement [Abstract] Acquisition-related contingent consideration Business Combination, Contingent Consideration, Liability, Total Schedule of Accrued Liabilities [Table Text Block] Accounts Receivable [Member] us-gaap_IncreaseDecreaseInOtherNoncurrentAssets Other assets us-gaap_IncreaseDecreaseInInventories Supplies Revenue from Contract with Customer Benchmark [Member] Trading Symbol Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Issuance of common stock under ESPP (in shares) Local Phone Number us-gaap_TableTextBlock Notes Tables Issuance of common stock under ESPP us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Long-term Contracts or Programs Disclosure [Text Block] Issuance of common stock upon exercise of stock options and vesting of restricted stock units (in shares) Issuance of common stock upon exercise of stock options and vesting of restricted stock units Financing activities Selling and marketing Line of Credit Facility, Lender [Domain] Change in Accounting Estimate by Type [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Stock-based compensation expense (employee) Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement related to employee. Change in Accounting Estimate, Type [Domain] Collaborative Arrangement [Member] Stock-based compensation expense (non-employee) Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement related to nonemployees. Sale of common stock in a public offering, net of offering costs (in shares) Stock Issued During Period, Shares, New Issues (in shares) Biopharmaceutical [Member] Represents biopharmaceutical. Testing [Member] Represents testing. Lender Name [Axis] vcyt_CashEquivalentsPercentageCollateralizedByUSTreasuryAndAgencySecurities Cash Equivalents, Percentage Collateralized by US Treasury and Agency Securities The percentage of cash equivalents collateralized by US treasury and agency securities. us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders’ equity Overnight Reverse Repurchase Agreements [Member] Represents overnight reverse repurchase agreements. Revenue Recognition [Member] Represents revenue recognition. Sale of common stock in a public offering, net of offering costs Noncash lease expense The noncash portion of lease expense. vcyt_IncreaseDecreaseInOperatingLeaseRightOfUseAssetLeaseLiability Operating lease liability The amount of increase (decrease) in operating lease right of use asset (lease liability). Interest on end-of-term debt obligation The amount of interest expense on end-of-term debt obligation. vcyt_NumberOfDiseaseAreasWithGenomicTesting Number of Disease Areas with Genomic Testing The number of disease areas with genomic testing. Loxo Oncology Inc [Member] Represents Loxo Oncology, Inc. Johnson and Johnson Services Inc JJSI [Member] Represents Johnson and Johnson Services, Inc. ("JJSI"). vcyt_CollaborativeAgreementPeriodOfPaymentsAfterFirstCommercial Collaborative Agreement, Period of Payments After First Commercial (Year) The period of payments commencing after the first commercial under the collaborative agreement. Research and development Accumulated deficit Collaborative [Member] Represents collaborative. vcyt_ContractAgreementTerm Contract Agreement, Term (Year) The period of the contract agreement. vcyt_ContractAgreementAutomaticRenewalTerm Contract Agreement, Automatic Renewal Term (Year) The period of the automatic renewal term of the contract agreement. Money Market Funds [Member] vcyt_ContractAgreementTerminationPeriod Contract Agreement, Termination Period (Day) The minimum notice period for termination of the contract agreement. Measurement Input, Discount Rate [Member] Cash and Cash Equivalents [Axis] Debt Disclosure [Text Block] us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet Net assets acquired Cash and Cash Equivalents [Domain] us-gaap_InterestExpense Interest expense Changes in operating assets and liabilities: us-gaap_StockholdersEquity Total stockholders’ equity Balance Balance Term Loan Advance [Member] Represents term loan advance. vcyt_DebtAgreementMaximumBorrowingCapacity Debt Agreement, Maximum Borrowing Capacity Maximum borrowing capacity of debt agreement. us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Headquarters and Laboratory Facilities in South San Francisco, California [Member] Represents headquarters and laboratory facilities in South San Francisco, California. Operating lease liability, net of current portion Long-term lease liabilities Laboratory and Office Space in Austin, Texas [Member] Represents laboratory and office space in Austin, Texas. Class of Stock [Axis] Loan and Security Agreement [Member] Represents the loan and security agreement. Silicon Valley Bank [Member] Represents Silicon Valley Bank. Long-term debt Prepayment Made Prior to November 3, 2018 [Member] Represents prepayment made prior to November 3, 2018. Present value of future lease payments vcyt_ValueOfSupportServicesToCounterParty Value of Support Services to Counter Party The value of support services to the counter party pursuant to the agreement. us-gaap_PaymentsToAcquireBusinessesGross Payments to Acquire Businesses, Gross Prepayment Made After November 3, 2018 and Before November 3, 2019 [Member] Represents prepayment made after November 3, 2018 and before November 3, 2019. Prepayment Made After November 3, 2019 [Member] Represents prepayment made after November 3, 2019. Current portion of operating lease liability Less: short-term lease liabilities Thyroid Cytopathology Partners TCP [Member] Represents Thyroid Cytopathology Partners ("TCP"). vcyt_RevenueFromAchievementOfDevelopmentMilestones Revenue from Achievement of Development Milestones The amount of revenue recognized for achievement of development milestones. vcyt_DebtInstrumentCovenantRevenueLevelExceptionAmountAvailableUnderRevolvingLineOfCredit Debt Instrument, Covenant, Revenue Level Exception, Amount Available Under Revolving Line of Credit The amount available under the revolving line of credit for failure to maintain the revenue level requirement to be excluded under the debt instrument covenant. CareDx [Member] Represents CareDx. vcyt_CommercialDevelopmentAgreementMaximumPaymentsReceivableFromCounterPartyUponAchievementOfMilestones Commercial Development Agreement, Maximum Payments Receivable from Counter Party Upon Achievement of Milestones The maximum payments that receivable from the counter party upon the achievement of commercial milestones. vcyt_DebtInstrumentPrepaymentPremium Debt Instrument, Prepayment Premium The amount of prepayment premium under the debt instrument. End-of-term debt obligation The end-of-term obligations of the debt instrument. Right-of-use assets - operating lease us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total future minimum lease payments Less: amount representing interest us-gaap_FinanceLeasePrincipalPayments Payment of finance lease liability 2023 Measurement Input Type [Axis] Medicare [Member] Represents Medicare. 2024 Measurement Input Type [Domain] United Healthcare [Member] Represents United Healthcare. us-gaap_UnrealizedGainLossOnInvestments Unrealized Gain (Loss) on Investments, Total Employee Stock Purchase Plan Shares [Member] Represents shares issued under the employee stock purchase plan.