Total long-term debt Long-Term Debt, Maturity, Year Three, Year Four And Year Five Long-Term Debt, Maturity, Year Three, Year Four And Year Five Schedule of Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Our Cash, Cash Equivalents and Marketable Securities Considered as Available for Sale by Type of Securities Debt Securities, Available-for-Sale [Table Text Block] Award Timing Predetermined Award Timing Predetermined [Flag] Entity File Number Entity File Number Tabular List, Table Tabular List [Table Text Block] Cash, Cash Equivalents and Investments in Marketable Securities Cash Cash Equivalents And Investments In Marketable Securities [Member] Cash, cash equivalents and investments in marketable securities. Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Debt Instrument, Tranche Type [Axis] Debt Instrument, Tranche Type [Axis] Debt Instrument, Tranche Type Common stock options issued and outstanding Share-Based Payment Arrangement [Member] Domestic research and development credits Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount License License [Member] Adjustment to Compensation: Adjustment to Compensation [Axis] Related Party - Gilead Sciences, Inc. Related Party Transactions Disclosure [Text Block] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Debt instrument, periodic payment, principal, term Debt Instrument, Periodic Payment, Principal, Term Debt Instrument, Periodic Payment, Principal, Term Revenues Revenue from Contract with Customer [Text Block] Stock-based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost Schedule Of Stock By Class [Table] Stock, Class of Stock [Table] BVF Partners L.P. BVF Partners L.P. [Member] BVF Partners L.P. Adjustment to Compensation, Amount Adjustment to Compensation Amount Percentage of revenues Concentration Risk, Percentage Unamortized discounts, issuance costs, charges, and payment-in-kind interest, net Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Consolidation Consolidation, Policy [Policy Text Block] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Stock Options Share-Based Payment Arrangement, Option [Member] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Income taxes paid Income Taxes Paid Percent Effective Income Tax Rate Reconciliation, Percent [Abstract] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Total stockholders’ equity Beginning balance Ending balance Equity, Attributable to Parent Measurement Frequency [Axis] Measurement Frequency [Axis] Debt Securities, Available-for-Sale [Table] Debt Securities, Available-for-Sale [Table] Insider Trading Policies and Procedures [Line Items] Summary of Property and Equipment, Net Property, Plant and Equipment [Table Text Block] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Issuance of common stock (in shares) Stock Issued During Period, Shares, New Issues Fair Value On Recurring Basis Fair Value, Recurring [Member] State State and Local Jurisdiction [Member] Cover [Abstract] Cover [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Maximum Maximum [Member] Options exercisable, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Depreciation and amortization Deferred Tax Assets Depreciation and Amortization Deferred tax assets depreciation and amortization. Summary of Information Related to Operating Leases Summary of Information Related to Operating Leases [Table Text Block] Summary of information related to operating leases. Beginning balance Ending balance Liability for Sale of Future Royalties Liability for sale of future royalties. Pennsylvania PENNSYLVANIA Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] 2018 Employee Stock Purchase Plan Two Thousand Eighteen Employee Stock Purchase Plan [Member] Two thousand eighteen employee stock purchase plan. Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Option continuation payment due upon fourth anniversary of agreement Option Continuation Payment Due Upon Fourth Anniversary Of Agreement Option continuation payment due upon Fourth anniversary of agreement. Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Second Stock Purchase Agreement Second Stock Purchase Agreement [Member] Second Stock Purchase Agreement. Trailing days average closing price Trailing Days Average Closing Price Trailing days average closing price. Retirement Benefits [Abstract] Retirement Benefits [Abstract] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Equity investment Effective Income Tax Rate Reconciliation, Nondeductible Expense, Equity Investment, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Equity Investment, Percent Loss before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Schedule of Long-Term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] STAR-221 Development Activities STAR-221 Development Activities [Member] STAR-221 Development Activities Proceeds from debt issuances, net Proceeds from Issuance of Debt Liabilities for indemnification rights and agreements Liabilities For Indemnification Rights And Agreements Liabilities for indemnification rights and agreements. Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Schedule of Cash Paid for Income Taxes, Net of Refunds Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Restricted Cash, Noncurrent, Statement of Financial Position [Extensible Enumeration] Restricted Cash, Noncurrent, Statement of Financial Position [Extensible Enumeration] Domestic Income (Loss) from Continuing Operations before Income Taxes, Domestic Summary of Stock-Based Compensation Expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Current portion of lease liabilities Other current liabilities - net current operating lease liabilities Operating Lease, Liability, Current AstraZeneca Agreement Astra Zeneca Agreement [Member] AstraZeneca Agreement. Document Fiscal Period Focus Document Fiscal Period Focus Cash, Cash Equivalents and Marketable Securities [Abstract] Cash, Cash Equivalents and Marketable Securities [Abstract] Cash, cash equivalents and marketable securities. Gilead Collaboration Agreement Option License And Collaboration Agreement [Member] Option, license and collaboration agreement. Collaborative Arrangements Collaborative Arrangement, Accounting Policy [Policy Text Block] Award Timing Method Award Timing Method [Text Block] Development services Development Services [Member] Development Services Furniture and equipment Furniture and Fixtures [Member] Award Type [Axis] Award Type [Axis] Deferred revenue, noncurrent ($43 and $234 to a related party) Deferred revenue, noncurrent Contract with Customer, Liability, Noncurrent Access rights Access Rights [Member] Access Rights Stock-Based Compensation Share-Based Payment Arrangement [Policy Text Block] Trading Symbol Trading Symbol 2029 Lessee, Operating Lease, Liability, to be Paid, Year Four Taiho Pharmaceutical Co., Ltd Taiho Pharmaceutical Co Ltd [Member] Taiho Pharmaceutical Co., Ltd. Option continuation payment due upon sixth anniversary of agreement Option Continuation Payment Due Upon Sixth Anniversary Of Agreement Option continuation payment due upon Sixth anniversary of agreement. Liability related to uncertain tax positions Liability for Uncertainty in Income Taxes, Current Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Entity Address, City or Town Entity Address, City or Town Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Funds received for stock purchase agreement Funds Received For Stock Purchase Agreement Funds received for stock purchase agreement. Restricted stock units issued Restricted Stock Units Restricted Stock Units (RSUs) [Member] Statement of Income Location, Balance [Domain] Statement of Income Location, Balance [Domain] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Number of programs, eligible to receive regulatory and commercial milestone payments Number Of Programs, Eligible To Receive Regulatory And Commercial Milestone Payments Number of programs, eligible to receive regulatory and commercial milestone payments. 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Summary of Revenues by Collaboration, Category of Revenue and Method of Recognition Disaggregation of Revenue [Table Text Block] Valuation allowance increased (decreased) value Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Liability for sale of future royalties Liability for Sale of Future Royalties [Member] Liability for sale of future royalties. 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] Prepaid expenses and other current assets Total prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Debt instrument, interest rate, effective percentage Debt Instrument, Interest Rate, Effective Percentage Total RSUs (in millions) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Income tax expense Provision for income taxes Income tax expense Income Tax Expense (Benefit) Debt instrument, basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Reimbursement from related party for shared costs Related Party Transaction Reimbursement From Related Party For Shared Costs Related party transaction reimbursement from related party for shared costs. Cash, cash equivalents, and short-term investments Cash, Cash Equivalents, and Short-Term Investments Property and equipment, gross Property, Plant and Equipment, Gross Executive Offices Research and Development and Business Operations Executive Offices Research And Development And Business Operations [Member] Executive offices, research and development and business operations. Other Significant Accounting Policies Other Significant Accounting Policies [Policy Text Block] Other significant accounting policies. Noncash lease expense Operating Lease, Right-of-Use Asset, Periodic Reduction Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Clinical, regulatory and commercialization milestone payments Clinical Regulatory And Commercialization Milestone Payments Clinical regulatory and commercialization milestone payments. Federal Income Tax Paid, Federal, after Refund Received All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Options vested and expected to vest, weighted average remaining contractual term (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term License and Collaboration Agreements [Table] License And Collaboration Agreements [Table] License and collaboration agreements. Summary of Transaction Price and Allocation of Transaction Price to the Performance Obligations Schedule Of Transaction Price and Allocated To Transaction Price to Performance Obligations [Table Text Block] Schedule of transaction price and allocated to transaction price to performance obligations. Nonvested, beginning balance (in shares) Nonvested, ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Tranche One Tranche One [Member] Tranche One Unrecognized compensation costs related to non-vested stock option awards Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Net cash used in operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Effective Income Tax Rate Reconciliation [Table] Effective Income Tax Rate Reconciliation [Table] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Property and equipment, estimated useful lives Useful Life (in years) Property, Plant and Equipment, Useful Life Subsequent Event Subsequent Event [Member] Number of research programs Number Of Research Programs Number of research programs. Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] R&D services R&D services R&D Services [Member] R&D Services PEO Total Compensation Amount PEO Total Compensation Amount Long-Term Debt, Type [Axis] Long-Term Debt, Type [Axis] Money market funds Money Market Funds [Member] Options vested and expected to vest, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Late-stage development programs Late Stage Development Programs Late Stage Development Programs Equity Components [Axis] Equity Components [Axis] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Sublease income Sublease Income Standby Letters of Credit Standby Letters of Credit [Member] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Amended Gilead Collaboration Agreement Amended Gilead Collaboration Agreement [Member] Amended gilead collaboration agreement. Number of reportable segments Number of Reportable Segments Deferred tax assets: Components of Deferred Tax Assets [Abstract] Entity Address, State or Province Entity Address, State or Province Impairment of long-lived assets (see Note 14, Leases) Impairment on right-of use assets Impairment of long-lived assets Operating Lease, Impairment Loss Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Total current liabilities Liabilities, Current Individual: Individual [Axis] Defined contribution plan, cost Defined Contribution Plan, Cost R&D costs amortization period Tax Cuts And Jobs Act Capitalized Research And Development Cost Amortization Period Tax cuts and jobs act capitalized research and development cost amortization period. Income Tax Jurisdiction [Domain] Income Tax Jurisdiction [Domain] Document Annual Report Document Annual Report Research and Development Research and development Research and Development Expense [Member] Debt instrument, payment in kind Debt Instrument, Payment-In-Kind Interest Debt Instrument, Payment-In-Kind Interest Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Entity Interactive Data Current Entity Interactive Data Current Deferred revenue Deferred Tax Assets, Deferred Income Options exercisable, aggregate intrinsic value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Stock based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Amount Adjusted for expense (income): Segment Reconciliation [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Milestone payments Milestone Payments Milestone payments. Square feet of leased office Area of Land ESPP Employee Stock Purchase Plan [Member] Employee stock purchase plan. Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] License License Revenue [Member] License Revenue Non-Cancelable Sub-Lease Non-Cancelable Sub-Lease [Member] Non-cancelable sub-lease. Other noncurrent assets Other Assets, Noncurrent Entity Central Index Key Entity Central Index Key Imputed effective rate of interest on unamortized portion of liability Imputed Effective Rate of Interest on Unamortized Portion of Liability Imputed effective rate of interest on unamortized portion of liability. PEO Name PEO Name Schedule of Maturities of Long-Term Debt Schedule of Maturities of Long-Term Debt [Table Text Block] Total revenues Revenues Total revenues Revenues 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] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Deferred revenue ($35 and $85 to a related party) Deferred revenue, current Contract with Customer, Liability, Current Capitalized research and development costs Deferred Tax Assets Capitalized Research and Development Costs Deferred tax assets capitalized research and development costs. Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Unrecognized compensation costs related to non-vested awards other than options Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Federal statutory income taxes Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Subsequent Event Type [Axis] Subsequent Event Type [Axis] Statement of Financial Position Location, Balance [Axis] Statement of Financial Position Location, Balance [Axis] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Entity Address, Address Line One Entity Address, Address Line One Research and development (Includes $25, ($39) and ($110) payments to/(from) a related party) Research and Development Expense Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] Fair Value as of Grant Date Award Grant Date Fair Value Net operating loss carryforwards Operating Loss Carryforwards Compensation and personnel costs Labor and Related Expense Schedule of Long-Term Debt Instruments Schedule of Long-Term Debt Instruments [Table Text Block] Debt instrument, term charge, percentage Debt Instrument, End Of Term Charge, Percentage Debt Instrument, End Of Term Charge, Percentage Number of exercise option to programs Number Of Exercise Option To Programs Number of exercise option to programs. RSUs granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period RSUs forfeited or canceled (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Related Party Transaction [Line Items] Related Party Transaction [Line Items] Collaboration term for current and future clinical programs Collaboration Term For Current And Future Clinical Programs Collaboration term for current and future clinical programs. Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Accrued interest receivable Interest Receivable, Current Counterparty Name [Domain] Counterparty Name [Domain] 2027 Lessee, Operating Lease, Liability, to be Paid, Year Two Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Weighted average remaining contractual term (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Purchase commitments cancellation notice period Purchase Commitments Cancellation Period Purchase commitments cancellation period. 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Company Selected Measure Name Company Selected Measure Name Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Accounts payable ($24 and $— to a related party) Accounts payable, current Accounts Payable, Current Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Volatility, minimum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Shares used to compute net loss per share, diluted (in shares) Weighted-average shares for diluted EPS (in shares) Weighted Average Number of Shares Outstanding, Diluted Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Reconciliation of Assets from Segment to Consolidated [Table] Reconciliation of Assets from Segment to Consolidated [Table] Total income tax expense Current Federal, State and Local, Tax Expense (Benefit) Summary of Changes of Liabilities for Sale of Future Royalties Summary of Changes Of Liabilities for Sale of Future Royalties [Table Text Block] Summary of changes of liabilities for sale of future royalties. Sale of stock, authorized consideration on transaction Sale Of Stock, Authorized Consideration On Transaction Sale Of Stock, Authorized Consideration On Transaction Entity Small Business Entity Small Business Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding State Current State and Local Tax Expense (Benefit) Long-Term Debt Long-Term Debt [Text Block] Document Transition Report Document Transition Report Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date Income Taxes Income Tax Disclosure [Text Block] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Options exercisable, weighted average remaining contractual term (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Document Type Document Type Level 3 Fair Value, Inputs, Level 3 [Member] Net Loss Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Loss Contingencies [Table] Loss Contingencies [Table] Product and Service [Axis] Product and Service [Axis] Research and development expense, net of recoveries Research And Development Expense, Recoveries Research And Development Expense, Recoveries Total revenues Total revenues from a customer Revenue from Contract with Customer, Excluding Assessed Tax Partnership reimbursements Impairment Losses Related to Real Estate Partnerships Milestone payments, received Milestone Payments, Received Milestone Payments, Received Options vested and expected to vest (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Options forfeited or canceled, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Percentage of outstanding common stock held Percentage Of Outstanding Common Stock Owned Percentage of outstanding common stock owned. Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Intrinsic value of shares exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Payments of employee taxes related to net settlement of equity awards Payment, Tax Withholding, Share-Based Payment Arrangement Capitalized contract cost, gross Capitalized Contract Cost, Gross Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Current liabilities: Liabilities, Current [Abstract] Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Research and development credits carryforwards Deferred Tax Assets, Tax Credit Carryforwards, Research Total operating expenses Operating Expenses Deferred revenue as of January 2024 Contract With Customer, Liability, Deferred Revenues At Amendment Closing Date Contract With Customer, Liability, Deferred Revenues At Amendment Closing Date Other Collaboration Revenue Other Collaboration Revenue [Member] Other Collaboration Revenue [Member] Risk-free interest rate, minimum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum Line of credit Long-Term Line of Credit Level 1 Fair Value, Inputs, Level 1 [Member] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Schedule Of Related Party Transactions By Related Party [Table] Related Party Transaction [Table] Net loss per share, diluted (in dollars per share) Net loss per share, diluted (in dollars per share) Earnings Per Share, Diluted Equity Award Programs Equity Award Programs [Member] Equity Award Programs [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Sale of stock, number of shares issued in transaction (in shares) Sale of Stock, Number of Shares Issued in Transaction State Income Tax Paid, State and Local, after Refund Received Auditor Location Auditor Location Marketable securities Debt Securities, Available-for-Sale, Current Federal Domestic Tax Jurisdiction [Member] Potential regulatory approval milestones payment receivable related to domvanalimab Potential Regulatory Approval Milestones Payment Receivable Related To Domvanalimab Potential regulatory approval milestones payment receivable related to domvanalimab. Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Other items Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent Total cash paid for income taxes, net of refunds Income Taxes Paid, Net Long-term debt, non-current (Contractual maturity 2030) Long-Term Debt, Gross Options granted, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Accrued personnel expenses Employee-related Liabilities, Current Property and Equipment Property, Plant and Equipment Disclosure [Text Block] Total undiscounted future minimum lease payments Lessee, Operating Lease, Liability, to be Paid Summary of Other Current Liabilities Other Current Liabilities [Table Text Block] Debt instrument, repayment, percentage Debt Instrument, Repayment, Percentage Debt Instrument, Repayment, Percentage Expiration Date Trading Arrangement Expiration Date Property and equipment, net Property and equipment, net Property, Plant and Equipment, Net Net loss (Numerator): Net Income (Loss) Attributable to Parent [Abstract] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Debt instrument, payment in kind, principal Debt Instrument, Payment-In-Kind Interest, Principal Debt Instrument, Payment-In-Kind Interest, Principal Entity Current Reporting Status Entity Current Reporting Status Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Federal statutory income taxes Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Financial Instrument [Axis] Financial Instrument [Axis] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Executive Category: Executive Category [Axis] Stock based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Percent Purchase price of common stock allocation to performance obligation Stock Issued During Period Value Determined To Premium On Purchase Of Common Stock And Allocated To Performance Obligation Stock issued during period value determined to premium on purchase of common stock and allocated to performance obligation. State taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Current Fiscal Year End Date Current Fiscal Year End Date Expected term (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Third Stock Purchase Agreement Amendment Third Stock Purchase Agreement Amendment [Member] Third Stock Purchase Agreement Amendment 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] Total shares of authorized common stock reserved for future issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant License and Collaborations Collaborative Arrangement Disclosure [Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Option payment upon achievement of certain development milestones Option Payment Upon Achievement Of Certain Development Milestones Option payment upon achievement of certain development milestones. Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Reserve for unrecognized tax benefits Beginning balance Ending balance Unrecognized Tax Benefits BVF Agreement BVF Agreement [Member] BVF Agreement [Member] Antidilutive securities excluded from computation of earnings per share, amount (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Weighted-average shares (Denominator): Weighted Average Number of Shares Outstanding, Diluted [Abstract] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Leases Lessee, Operating Leases [Text Block] Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Measure: Measure [Axis] Contract with customer, asset, before allowance for credit loss Contract with Customer, Asset, before Allowance for Credit Loss Credit related losses Financing Receivable, Credit Loss, Expense (Reversal) Long-term marketable securities Debt Securities, Available-for-Sale, Noncurrent Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Taiho Agreement Option And License Agreement [Member] Option and license agreement. Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Common stock and additional paid-in capital Common Stock Including Additional Paid in Capital [Member] Entity Tax Identification Number Entity Tax Identification Number Beginning balance, weighted average grant date fair value (in dollars per share) Ending balance, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Debt Instrument, additional committed amount Debt Instrument, Additional Committed Amount Debt Instrument, Additional Committed Amount Option fee per program for all other programs entering clinical development to exercise option Option Fee Per Program For All Other Programs Entering Clinical Development To Exercise Option Option fee per program for all other programs entering clinical development to exercise option. 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Other current liabilities Total other current liabilities Other Liabilities, Current Other Other Sundry Liabilities, Current Debt instrument, cash balance requirement, minimum, percentage Debt Instrument, Cash Balance Requirement, Minimum, Percentage Debt Instrument, Cash Balance Requirement, Minimum, Percentage Statement [Line Items] Statement [Line Items] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Organization [Line Items] Organization [Line Items] Organization. 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Options exercised, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Award Timing Disclosures [Line Items] Clinical regulatory milestone payments Clinical Regulatory Milestone Payments Clinical Regulatory Milestone Payments Non-refundable payments received Non-refundable Payments Received Non-refundable payments received. 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Options granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Use of Estimates Use of Estimates, Policy [Policy Text Block] Schedule of Assumptions Used to Calculate Fair Value and the Weighted-Average Grant Date Fair Value of Stock Options Granted Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block] Subsequent Events Subsequent Events [Text Block] Insider Trading Arrangements [Line Items] Contract with customer, liability, cumulative catch-up adjustment to revenue, earnings per share, diluted (in dollars per share) Contract With Customer, Liability, Cumulative Catch-up Adjustment To Revenue, Earnings Per Share, Diluted Contract With Customer, Liability, Cumulative Catch-up Adjustment To Revenue, Earnings Per Share, Diluted Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Royalties payable term Royalties Payable Term Royalties Payable Term Reimbursement of research and development expense Reimbursement of Research and Development Expense Reimbursement of research and development expense Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Additions for tax positions taken in current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Taiho Collaboration Taiho Collaboration [Member] Taiho Collaboration Issuance of common stock Stock Issued During Period, Value, New Issues Deferred revenue, non-refundable payment Deferred Revenue, Non-Refundable Payment Deferred Revenue, Non-Refundable Payment Option payments received Option Payment Received Option payment received. Counterparty Name [Axis] Counterparty Name [Axis] Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Fair Value Debt Securities, Available-for-Sale Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Prime Rate [Member]