Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Commercial Milestones Commercial Milestones [Member] Commercial milestones. Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum Maximum [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Deductions from collaboration agreements Contract With Customer, Liability, Deductions From Collaboration Agreements Contract With Customer, Liability, Deductions From Collaboration Agreements Title of 12(b) Security Title of 12(b) Security Aggregate Intrinsic Value Aggregate Intrinsic Value [Abstract] Aggregate Intrinsic Value Document Fiscal Year Focus Document Fiscal Year Focus Adjustment to Compensation, Amount Adjustment to Compensation Amount Financial Instrument [Axis] Financial Instrument [Axis] Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Segment Reporting [Abstract] Common stock, $0.001 par value; 75.5 shares issued and 65.5 shares outstanding as of September 30, 2026, and 73.5 shares issued and 63.5 outstanding as of December 31, 2025 Common Stock, Value, Issued 2027 Lessee, Operating Lease, Liability, to be Paid, Year One Employee expenses Employee-related Liabilities, Current Schedule of Long-Term Debt Schedule of Long-Term Debt Instruments [Table Text Block] Loan forgiveness Debt Instrument Loan Forgiveness Debt instrument loan forgiveness. Restatement Determination Date Restatement Determination Date Contract revenue receivable if milestones achieved Beginning balance Ending balance Contract with Customer, Asset, after Allowance for Credit Loss Upfront Payment for Amended License Agreement and Novartis License and Asset Agreements Upfront Payment For Amended License Agreement And Novartis License And Asset Agreements [Member] Upfront Payment For Amended License Agreement And Novartis License And Asset Agreements General and administrative and commercial expenses Accrued General And Administrative And Commercial, Current Accrued General And Administrative And Commercial, Current Amendment Flag Amendment Flag Current liabilities: Liabilities, Current [Abstract] Research Collaboration And License Agreements [Table] Research Collaboration And License Agreements [Table] Research collaboration and license agreements. Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Schedule of Available-for-Sale Marketable Securities Debt Securities, Available-for-Sale [Table Text Block] Debt instrument interest payments term (in months) Debt Instrument Interest Payments Term Debt instrument interest payments term. Leases [Abstract] Leases [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Schedule of cash and cash equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Property, Plant, and Equipment [Abstract] Property, Plant, and Equipment [Abstract] Entity Address, State or Province Entity Address, State or Province Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross PEO Total Compensation Amount PEO Total Compensation Amount Beginning balance Ending balance Accounts Payable, Contract Balances, Current Accounts Payable, Contract Balances, Current Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Basic (in shares) Weighted average common shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Net accretion of bond discounts/premiums Accretion (Amortization) of Discounts and Premiums, Investments Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current ARV-027 ARV-027 [Member] ARV-027 Commitments And Contingencies [Table] Commitments And Contingencies [Table] Commitments And Contingencies Deductions Contract with Customer, Asset, Deductions Contract with Customer, Asset, Deductions Entity Address, City or Town Entity Address, City or Town Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Collaboration settlement liability Beginning balance Ending balance Collaboration Liability Collaboration Settlement Liability Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Common stock reserved for issuance represented as percentage on outstanding common stock Increase In Capital Shares Reserved For Future Issuance Represented As Percentage On Outstanding Common Stock Increase in capital shares reserved for future issuance represented as percentage on outstanding common stock. Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Royalty payment Payments for Royalties Level 2 Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Regulatory Milestone Related to Marketing Approvals Regulatory Milestone Payments [Member] Regulatory milestone payments. Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Less: current installments included within Accounts payable and accrued liabilities Long-Term Debt, Current Maturities Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Milestone Payment Upon Approval of First and Second Royalty Products Milestone Payment Upon Approval Of First And Second Royalty Products [Member] Milestone Payment Upon Approval Of First And Second Royalty Products License revenue License [Member] Consulting Agreement, COBRA Reimbursement Consulting Agreement, COBRA Reimbursement [Member] Consulting Agreement, COBRA Reimbursement Change in Accounting Estimate, Type [Domain] Effect of Change in Accounting Estimate, Type [Domain] Debt Instrument [Table] Schedule of Long-Term Debt Instruments [Table] Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Deferred revenue Increase (Decrease) in Contract with Customer, Liability Schedule of Reportable Segment Financial Information Segment Reporting [Table Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Related and Nonrelated Parties [Axis] Related and Nonrelated Parties [Axis] Total intrinsic value of RSUs released Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options, Aggregate Intrinsic Value, Released In Period Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options, Aggregate Intrinsic Value, Released In Period Schedule of Components of Accounts Payable and Accrued Liabilities Schedule of Accrued Liabilities [Table Text Block] Less: Segment Reporting, Reconciliation [Abstract] Total Long-Term Debt Property, Equipment and Leasehold Improvements Property, Plant, and Equipment [Text Block] Laboratory equipment Laboratory Equipment [Member] Laboratory equipment. Schedule of Maturities of Operating Lease Liabilities Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Document Period End Date Document Period End Date Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Net cash provided by investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Debt instrument face amount Debt Instrument, Face Amount Contract assets Increase (Decrease) in Contract with Customer, Asset 2028 Lessee, Operating Lease, Liability, to be Paid, Year Two Security Exchange Name Security Exchange Name Treasury Stock, at cost (10.0 shares as of September 30, 2026 and December 31, 2025) Treasury Stock, Common, Value Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Lessee Lease Description [Line Items] Lessee, Lease, Description [Line Items] Issuance of common stock under equity incentive plans Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture Purchases of marketable securities Payments to Acquire Marketable Securities Total fair value of RSUs vested Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Accumulated other comprehensive (loss) income Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Current portion of operating lease liabilities Operating Lease, Liability, Current Schedule of Property, Equipment and Leasehold Improvements Property, Plant, and Equipment [Table Text Block] Condensed Consolidated Statements of Comprehensive Income (Loss) Statement of Comprehensive Income [Abstract] (Loss) Earnings Per Common Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name (Loss) earnings per common share Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Total liabilities Liabilities Trading Symbol Trading Symbol Geographical [Domain] Geographical [Domain] Sales Based Milestone Payments Sales Based Milestone Payments [Member] Sales-based milestone payments. Purchases of property, equipment and leasehold improvements Payments to Acquire Property, Plant, and Equipment Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Cost of license revenue Cost Of License Revenue, Operating Expense Cost Of License Revenue, Operating Expense Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Income taxes Accrued Income Taxes, Current Contract liabilities: Deferred revenue Change in Contract with Customer, Liability [Roll Forward] Change in Contract with Customer, Liability Company Selected Measure Name Company Selected Measure Name Sale of Stock [Domain] Sale of Stock [Domain] Schedule of restrictions on cash and cash equivalents Restrictions on Cash and Cash Equivalents [Table Text Block] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] License First Licensed Product License First Licensed Product [Member] License First Licensed Product Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Related Party Transactions [Abstract] Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Other receivables Other Receivables, Net, Current Compensation Amount Outstanding Recovery Compensation Amount Amortization of collaboration contract asset Capitalized Contract Cost, Amortization Individual: Individual [Axis] Diluted (in shares) Weighted average common shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Removal of Combination Trials Removal Of Combination Trials [Member] Removal Of Combination Trials Underlying Security Market Price Change Underlying Security Market Price Change, Percent Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Less: imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Additions Accounts Receivable, After Allowance For Credit Loss, Current, Additions Accounts Receivable, After Allowance For Credit Loss, Current, Additions Payments received Accounts Receivable, After Allowance For Credit Loss, Current, Payments Received Accounts Receivable, After Allowance For Credit Loss, Current, Payments Received Revenue from Contract with Customer [Abstract] Denominator adjustments for diluted EPS (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment ARV-102 ARV-102 [Member] ARV-102 Operating cash flows from operating lease Operating Lease, Payments Additions Accounts Payable, Contract Balances, Current Additions Accounts Payable, Contract Balances, Current Additions Award Timing Predetermined Award Timing Predetermined [Flag] Restricted cash Restricted Cash, Current Treasury Treasury Stock, Common [Member] Intrinsic value of options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Stock-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Effective tax rate, percentage Effective Income Tax Rate Reconciliation, Percent Non-program-specific external expense Research And Development Expense, Non-Program Specific Research And Development Expense, Non-Program Specific Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Total lease payments Lessee, Operating Lease, Liability, to be Paid Collaboration liability Increase (Decrease) In Collaboration Liability Increase (Decrease) In Collaboration Liability Number of stock options and RSUs (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Beginning balance (in dollars per share) Ending balance (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value All Executive Categories All Executive Categories [Member] Government securities US Government Debt Securities [Member] Piper Sandler and Cantor Piper Sandler And Cantor [Member] Piper sandler and cantor. Operating lease liability Increase (Decrease) in Operating Lease Liability Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Other comprehensive (loss) income: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Preferred stock par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Accounts receivable related to collaborations Change in Accounts Receivable, after Allowance for Credit Loss [Roll Forward] Change in Accounts Receivable, after Allowance for Credit Loss Upfront license payment Revenue from Contract with Customer, Aggregate Upfront Payment Revenue from Contract with Customer, Aggregate Upfront Payment Plan Name [Domain] Plan Name [Domain] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Beginning balance (in dollars per share) Ending balance (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Vepdegestrant Vepdegestrant [Member] Vepdegestrant Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Development Milestone Payments Development Milestone Payments [Member] Development milestone payments. Current portion of collaboration liability Collaboration Liability, Current Collaboration Liability, Current Percentage of incremental borrowing for lease payments Percentage Of Incremental Borrowing For Lease Payments Percentage of incremental borrowing for lease payments. Schedule of Basic and Diluted (Loss) Earnings per Common Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Risk free interest rate, maximum (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Segment Information Segment Reporting [Text Block] Minimum Minimum [Member] Expiration Date Trading Arrangement Expiration Date Stock Compensation And Bonus Expense Stock Compensation And Bonus Expense [Member] Stock Compensation And Bonus Expense Schedule of Sources of Revenue Disaggregation of Revenue [Table Text Block] Weighted average common shares outstanding Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Location, Statement of Income, Balance [Axis] Location, Statement of Income, Balance [Axis] Number Of Authorized Shares Not Disclosed Number Of Authorized Shares Not Disclosed Number Of Authorized Shares Not Disclosed Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Outstanding (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted-Average Remaining Contractual Term Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Exercise price (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Exercise Price Vested and exercisable, ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Collaboration agreement direct and incremental costs incurred Direct And Incremental Costs Incurred To Obtain The Contract Direct and incremental costs incurred to obtain the contract. Payments for collaboration Payments For Collaboration Payments For Collaboration Exercise Price Award Exercise Price Restructuring Cost [Table] Restructuring Cost [Table] Cash flows from investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Related Party Transaction [Axis] Related Party Transaction [Axis] Segment Reporting [Line Items] Segment Reporting [Line Items] Compensation expense not yet recognized Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Document Quarterly Report Document Quarterly Report Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments [Domain] Segments [Domain] Long-Term Debt Debt Disclosure [Text Block] Percentage of liquidated damages Percentage Of Liquidated Damages Percentage of liquidated damages. Repayments of long-term debt Repayments of Long-Term Debt Contract assets: Collaboration contract asset Change in Collaboration Contract Asset And Other Assets [Roll Forward] Change in Collaboration Contract Asset And Other Assets Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Other receivables Increase (Decrease) in Other Receivables Restructuring accrual Restructuring Reserve Equity Component [Domain] Equity Component [Domain] Additions Contract with Customer, Asset, Additions Contract with Customer, Asset, Additions PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount License Agreement, Reimbursement Fees License Agreement, Reimbursement Fees [Member] License Agreement, Reimbursement Fees Adoption Date Trading Arrangement Adoption Date Proceeds from exercise of stock options and issuance of ESPP shares Proceeds From Exercise Of Stock Options And Issuance Of Employee Stock Shares Proceeds From Exercise Of Stock Options And Issuance Of Employee Stock Shares Interest Rate Debt instrument bearing interest rate Debt Instrument, Interest Rate, Stated Percentage Counterparty Name [Domain] Counterparty Name [Domain] Total stockholders’ equity Beginning balance Ending balance Equity, Attributable to Parent Total other income Nonoperating Income (Expense) Milestone payment the Company will make Collaborative Arrangement, Rights And Obligations, Milestone Payment Collaborative Arrangement, Rights And Obligations, Milestone Payment Restructuring Type [Axis] Restructuring Type [Axis] Assets Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Total Operating Lease, Liability Collaboration Agreement Revenue Collaboration Agreement Revenue [Member] Collaboration Agreement Revenue Insider Trading Policies and Procedures [Line Items] Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Accounts Payable and Accrued Liabilities Accounts Payable and Accrued Liabilities Disclosure [Text Block] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Type of Restructuring [Domain] Type of Restructuring [Domain] Decrease related to modifications Share-Based Payment Arrangement, Expense, Decrease Related To Modifications Share-Based Payment Arrangement, Expense, Decrease Related To Modifications Annual increase in reserved shares as percentage of outstanding common stock Share-Based Compensation Arrangement by Share-Based Payment Award, Percentage of Outstanding Stock Maximum Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Number of operating segments Number of Operating Segments Antidilutive securities excluded from computation of diluted net loss per common share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount RSUs Restricted Stock Units (RSUs) [Member] Schedule of Securities Excluded From Computation of Diluted Net Loss Per Common Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Entity Central Index Key Entity Central Index Key Weighted Average Weighted Average [Member] Less: accumulated depreciation and amortization Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization All Adjustments to Compensation All Adjustments to Compensation [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Net cash used in operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Consideration payable Consideration Payable Under Collaboration Agreement Consideration Payable Under Collaboration Agreement Regulatory and Sales-Based Milestones Regulatory And Sales Based Milestones [Member] Regulatory and sales-based milestones. Income Statement [Abstract] Income Statement [Abstract] Stockholders’ equity: Equity, Attributable to Parent [Abstract] Common stock, shares issued (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Document Transition Report Document Transition Report Annual increase in reserved shares of common stock (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Other Increases (Decreases) in Period Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Operating expenses: Operating Expenses [Abstract] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Schedule of Assumptions Used to Determine Fair Value of Stock Options Granted Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Amortization Collaboration Contract Asset, Amortization During Period Collaboration Contract Asset, Amortization During Period Equity Distribution Agreement Equity Distribution Agreement [Member] Equity distribution agreement. Contract assets: Contract assets Change in Collaboration Contract Asset [Abstract] Change in Collaboration Contract Asset ARV-806 ARV-806 [Member] ARV-806 Options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] City Area Code City Area Code Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Inducement grants (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Inducement Grants Share-Based Compensation Arrangement by Share-Based Payment Award, Inducement Grants Amortization of right-of-use assets Operating Lease, Right-of-Use Asset, Periodic Reduction Name Forgone Recovery, Individual Name Compensation expense not yet recognized, period of recognition (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Weighted Average Grant Date Fair Value Per Share Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Cash paid for amounts included in the measurement of lease liabilities: Cash Paid For Amounts Included In Measurement Of Lease Liabilities [Abstract] Cash paid for amounts included in the measurement of lease liabilities. Statement [Line Items] Statement [Line Items] Total assets Assets Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Common stock reserved for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Pfizer Collaboration Agreement Pfizer Collaboration Agreement [Member] Pfizer Collaboration Agreement Weighted-average grant date fair value of options (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax ARV-6723 ARV-6723 [Member] ARV-6723 Equity Share-Based Payment Arrangement [Text Block] Collaboration liability Collaboration Liability, Noncurrent Collaboration Liability, Noncurrent Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Issuance of common stock for pre-funded warrants (in shares) Stock Issued During Period, Shares, New Issues PEO PEO [Member] 2028 Long-Term Debt, Maturity, Year Two Development activities Revenue From Contract With Customer, Development Activity Costs, Maximum Reimbursement Revenue From Contract With Customer, Development Activity Costs, Maximum Reimbursement Compensation expense Share-Based Payment Arrangement, Expense Marketable securities Marketable Securities, Current Novartis Pharma AG Novartis Pharma AG [Member] Novartis Pharma AG Program-specific external expense Research And Development Expense, Program Specific Research And Development Expense, Program Specific Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Revenue recognized Revenue recognized from balances held at the beginning of the period Contract with Customer, Liability, Revenue Recognized Payables and Accruals [Abstract] Payables and Accruals [Abstract] Accumulated Deficit Retained Earnings [Member] Operating lease liabilities Operating Lease, Liability, Noncurrent Total operating expenses Operating expenses Operating Expenses Cancelled/ Forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Cancelled/ Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Diluted (in dollars per share) Net loss per common share, basic (in dollars per share) Earnings Per Share, Diluted Entity Current Reporting Status Entity Current Reporting Status Net cash provided by (used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Expected volatility, maximum (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum Total Shareholder Return Amount Total Shareholder Return Amount Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Required milestone payments Required Milestone Payments Required Milestone Payments Research and development Total research and development expense Research and Development Expense Adjustments to reconcile net income (loss) to net cash used in operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Cash flows from financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Revenue Revenue from Contract with Customer, Excluding Assessed Tax Property, equipment and leasehold improvements, net Property, equipment and leasehold improvements, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Hourly rate Related Party, Hourly Rate Related Party, Hourly Rate Financial Instruments [Domain] Financial Instruments [Domain] Updated Research Timelines Updated Research Timelines [Member] Updated Research Timelines Rigel Pharmaceuticals, Inc. Rigel Pharmaceuticals, Inc. [Member] Rigel Pharmaceuticals, Inc. Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Payments received Proceeds from Collaborators Cancelled/ Forfeited (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Vested and expected to vest (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Hours worked in a month before hourly rate applies Related Party, Overtime Threshold, Minimum Number Of Hours In A Month Related Party, Overtime Threshold, Minimum Number Of Hours In A Month Risk free interest rate, minimum (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum Schedule of Restricted Stock Grant Activity Nonvested Restricted Stock Shares Activity [Table Text Block] Segment Reporting [Table] Segment Reporting [Table] Common stock, shares remained available for purchase (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Schedule of Minimum Future Payments on Long-Term Debt Schedule of Maturities of Long-Term Debt [Table Text Block] Related Party Transaction [Table] Related Party Transaction [Table] Sale of Stock [Axis] Sale of Stock [Axis] Weighted Average Remaining Contractual Term (Years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Schedule of Components of Lease Expense Lease, Cost [Table Text Block] (Loss) earnings per common share Earnings (Loss) Per Common Share, EPS [Abstract] Earnings (Loss) Per Common Share, EPS Commitments and Contingencies Disclosure [Abstract] Other income Other Nonoperating Income (Expense) [Abstract] All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Office equipment Office Equipment [Member] (Loss) income from operations Operating Income (Loss) Current Fiscal Year End Date Current Fiscal Year End Date Consulting Agreement, Lump Sum Payment Consulting Agreement, Lump Sum Payment [Member] Consulting Agreement, Lump Sum Payment Research Collaboration And License Agreements [Abstract] Research Collaboration And License Agreements Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Vepdegestrant ARV-471 ARV-471 [Member] ARV-471 Related Party Transaction [Domain] Related Party Transaction [Domain] Accounts payable related to collaborations Change in Accounts Payable, after Allowance for Credit Loss [Roll Forward] Change in Accounts Payable, after Allowance for Credit Loss Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Corporate bonds Corporate Bond Securities [Member] Schedule of Stock Option Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Common stock, shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Other programs Other Programs [Member] Other Programs Nature of Business and Basis of Presentation Business Description and Basis of Presentation [Text Block] Maturities of marketable securities Proceeds From Maturities Of Marketable Securities Proceeds from maturities of marketable securities. Treasury stock (in shares) Beginning balance (in shares) Ending balance (in shares) Treasury Stock, Common, Shares Income Statement And Statement Of Comprehensive Income [Abstract] Income Statement And Statement Of Comprehensive Income Contingent payments Revenue, Remaining Performance Obligation, Maximum Contingent Payments Based On Milestones Revenue, Remaining Performance Obligation, Maximum Contingent Payments Based On Milestones Equity Components [Axis] Equity Components [Axis] Accounts receivable Increase (Decrease) in Accounts Receivable Product and Service [Domain] Product and Service [Domain] Cash paid for taxes Income Tax Paid, after Refund Received Option Payments To License Agreement Option Payments To License Agreement [Member] Option payments to license agreement. Entity Interactive Data Current Entity Interactive Data Current Research Collaboration And License Agreements [Line Items] Research Collaboration And License Agreements [Line Items] Research collaboration and license agreements. Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Accounts payable and accrued liabilities Total accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Entity Small Business Entity Small Business Sales-Based Milestones Sales Based Milestones [Member] Sales-based milestones. 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Award Type [Domain] Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Remainder of 2026 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Marketable Securities and Fair Value Measurements Fair Value Disclosures [Text Block] Supplemental disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Expected term (years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Share repurchases (treasury stock) (in shares) Treasury Stock, Shares, Acquired Vested and expected to vest (in Years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted-Average Remaining Contractual Term PEO Name PEO Name Geographical [Axis] Geographical [Axis] Leasehold improvements Leasehold Improvements [Member] Contract with customer, liability Beginning balance Ending balance Contract with Customer, Liability Other segment expense, net Segment Reporting, Other Segment Item, Amount Long-Lived Asset, Class [Axis] Long-Lived Asset, Class [Axis] Risks and Uncertainties Concentration Risk, Credit Risk, Policy [Policy Text Block] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Interest expense Interest Expense, Debt Milestone Revenue Milestone Revenue [Member] Milestone Revenue Lessee Lease Description [Table] Lessee, Lease, Description [Table] Share repurchases (treasury stock) Treasury Stock, Value, Acquired, Cost Method Schedule of Supplemental Cash Flow Information Related to Leases Schedule Of Supplemental Cash Flow Information Related To Leases [Table Text Block] Supplemental cash flow information related to leases. 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Unrealized (loss) gain on available-for-sale securities Unrealized loss on available-for-sale securities Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Accumulated deficit Retained Earnings (Accumulated Deficit) Restructuring and Related Activities [Abstract] Product and Service [Axis] Product and Service [Axis] License Second Licensed Product License Second Licensed Product [Member] License Second Licensed Product Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Common Stock [Member] Fair Value Debt Securities, Available-for-Sale Genentech Genentech Incorporation And F Hoffman La Roche Limited [Member] Genentech, Incorporation. and F. Hoffman-La Roche Limited. Change in Accounting Estimate by Type [Axis] Effect of Change in Accounting Estimate, Type [Axis] Employee Severance Employee Severance [Member] Operating lease cost Operating Lease, Cost Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Reduction in workforce (as a percent) Restructuring and Related Cost, Number of Positions Eliminated, Period Percent Expected dividend yield (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Payments made Accounts Payable, Contract Balances, Current Payments Accounts Payable, Contract Balances, Current Payments State of Connecticut CONNECTICUT 2018 Assistance Agreement Two Thousand And Eighteen Assistance Agreement [Member] Two thousand and eighteen assistance agreement. Contingent payments Revenue, Remaining Performance Obligation, Contingent Payments Revenue, Remaining Performance Obligation, Contingent Payments Equity Awards Adjustments Equity Awards Adjustments [Member] Cash, cash equivalents, restricted cash and marketable securities Cash, Cash Equivalents, Restricted Cash and Marketable Securities Cash, Cash Equivalents, Restricted Cash and Marketable Securities Research Collaboration and License Agreements Collaborative Arrangement Disclosure [Text Block] Number of inducement grants (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Inducement Grants Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Inducement Grants Total liabilities and stockholders’ equity Liabilities and Equity Stock options Share-Based Payment Arrangement, Option [Member] Research and development expenses Accrued Research And Development Expense Current Accrued research and development expense current. Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Restructuring charges (income) Restructuring Charges Related and Nonrelated Parties [Domain] Related and Nonrelated Parties [Domain] Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Plan Name [Axis] Plan Name [Axis] Tabular List, Table Tabular List [Table Text Block] Additional paid-in capital Additional Paid in Capital Other expense, net Other Nonoperating Income (Expense) Name Awards Close in Time to MNPI Disclosures, Individual Name Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Cancelled/ Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period General and administrative General and administrative expense General and Administrative Expense Long-Lived Asset, Class [Domain] Long-Lived Asset, Class [Domain] Supplemental non-cash information: Supplemental Non Cash Information Related To Leases [Abstract] Supplemental non-cash information related to leases. Schedule Of Property Plant And Equipment [Table] Property, Plant, and Equipment [Table] Preferred stock, $0.001 par value, zero shares issued and outstanding as of September 30, 2026 and December 31, 2025, respectively Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Collaboration Agreement Collaboration Agreement [Member] Collaboration agreement. Restructuring Activity Restructuring and Related Activities Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Success-Based Milestone Payments Success-Based Milestone Payments [Member] Success-Based Milestone Payments Vested and expected to vest (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Name Measure Name Pfizer, Inc. Pfizer Inc. [Member] Pfizer Inc. Income Taxes Income Tax Disclosure [Text Block] Accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Additional Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Deductions Collaboration Liability, Deductions Collaboration Liability, Deductions Director Director [Member] Additions Collaboration Liability, Additions Collaboration Settlement Liability , Additions Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and Cash Equivalent Development activities, percentage to refund Development Activities, Amount To Refund, Percentage Development Activities, Amount To Refund, Percentage Contract and other assets Collaboration Contract Asset And Other Assets Collaboration contract asset and other assets. Company Selected Measure Amount Company Selected Measure Amount Entity Address, Address Line Two Entity Address, Address Line Two Issuance of common stock under equity incentive plans (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Yale University Yale University [Member] Yale University Current assets: Assets, Current [Abstract] Operating lease, weighted average remaining lease term (in years) Operating Lease, Weighted Average Remaining Lease Term Non-PEO NEO Non-PEO NEO [Member] Entity Address, Address Line One Entity Address, Address Line One Right-of-use assets obtained in exchange for new lease obligations Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Income tax expense Income tax expense Income tax expense Income Tax Expense (Benefit) 2018 Plan 2018 Plan Two Thousand Eighteen Stock Incentive Plan [Member] Two thousand eighteen stock incentive plan. Award Timing Method Award Timing Method [Text Block] Net (decrease) increase in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Other research and development expense Other Research and Development Expense Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Expected volatility, minimum (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Net (loss) income Net (loss) income Net loss Segment net (loss) income Net Income (Loss) Attributable to Parent Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] License Agreement, Sales-Based Royalties License Agreement, Sales-Based Royalties [Member] License Agreement, Sales-Based Royalties Restatement Determination Date: Restatement Determination Date [Axis] Reportable Segment Reportable Segment [Member] Reportable Segment ARV-393 ARV-393 [Member] ARV-393 Sales of marketable securities Proceeds From Sale Of Marketable Securities Proceeds from sale of marketable securities. Interest income, net Interest income, net Investment Income, Interest Vested and exercisable (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Schedule of Contract Balances Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Milestone Payment on First Anniversary of Signing Milestone Payment On First Anniversary Of Signing [Member] Milestone Payment On First Anniversary Of Signing Revenue Revenues [Abstract] License Agreement, Excluding Cost Reimbursement Fees License Agreement, Excluding Cost Reimbursement Fees [Member] License Agreement, Excluding Cost Reimbursement Fees Accrued liabilities Accrued Liabilities [Abstract] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Beginning balance Ending balance Collaboration Contract Asset Collaboration Contract Asset