Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Consolidated Entities [Axis] Consolidated Entities [Axis] Liability related to the sale of future royalties Royalties, Liability, Noncurrent Royalties, Liability, Noncurrent Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Office space leases (in sq ft) Land Subject to Ground Leases Net loss attributable to noncontrolling interest, net of tax Net Income (Loss) Attributable to Noncontrolling Interest Pay vs Performance Disclosure [Line Items] Proceeds from sale of marketable debt securities Proceeds from Sale of Debt Securities, Available-for-Sale Entity Voluntary Filers Entity Voluntary Filers Accrued expenses Accrued Liabilities, Current Statistical Measurement [Domain] Statistical Measurement [Domain] Wisconsin WISCONSIN Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Award Type Award Type [Domain] Fair Value as of Grant Date Award Grant Date Fair Value Share-based payment award (in shares) Beginning of period (in shares) End of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (Accretion) amortization of note premiums/discounts Investment Income, Net, Amortization of Discount and Premium Technology License Commitments Technology License Commitments [Member] Technology license commitments. Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Research and Development Research and Development Expense, Policy [Policy Text Block] Investments, Debt and Equity Securities [Abstract] Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Effect of exchange rate on cash, cash equivalents and restricted cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations Douglass Given [Member] Douglass Given Intangible assets subject to amortization, impairment Impairment of Intangible Assets, Finite-Lived MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Foreign-derived intangible income deduction Effective Income Tax Rate Reconciliation, FDII, Percent Accounts payable Accounts Payable, Current Weighted-Average Remaining Contractual Term, Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Restatement Determination Date: Restatement Determination Date [Axis] Stock compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Percent Corporate debt securities Corporate Debt Securities [Member] Purchases of investments Payments to Acquire Investments Total other (expense) income Nonoperating Income (Expense) U.S. federal statutory income tax Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Commitments and contingencies (Note 7) Commitments and Contingencies Insider Trading Policies and Procedures [Line Items] Number of Options Outstanding, Exercisable (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Tax increment financing award Tax Increment Financing Award Tax Increment Financing Award Construction in progress Construction in Progress, Gross Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] 2028 Lessee, Operating Lease, Liability, to be Paid, Year Five Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Stockholders' Equity Equity [Text Block] Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Proceeds from the sale of future royalties Proceeds from Issuance of Common Stock Geographical Geographical [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Income Taxes Income Tax Disclosure [Text Block] Deferred revenue Increase (Decrease) in Contract with Customer, Liability Expected dividend yield Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Leases Lessee, Leases [Policy Text Block] Customer [Axis] Customer [Axis] Current liabilities: Liabilities, Current [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Weighted- Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Diluted (in dollars per share) Earnings Per Share, Diluted PEO Total Compensation Amount PEO Total Compensation Amount Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Land Land Upfront payment Cash Received As Due Under Collaboration Agreement Cash received as due under collaboration agreement. Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Level 3 Fair Value, Inputs, Level 3 [Member] Options (in shares) Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Trading Symbol Trading Symbol Restricted Stock Units, Market-Based Restricted Stock Units, Market-Based [Member] Restricted Stock Units, Market-Based Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Interest income Investment Income, Interest and Dividend Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Weighted-average grant date fair value per share Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Schedule Of Collaborative Arrangements And Noncollaborative Arrangement Transactions [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Debt securities Debt Securities [Member] Net loss attributable to Arrowhead Pharmaceuticals, Inc. Net loss attributable to Arrowhead Pharmaceuticals, Inc. Net Income (Loss) Thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Five Total current liabilities Liabilities, Current Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Foreign Currency Translation Adjustments Foreign Currency Transactions and Translations Policy [Policy Text Block] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Company Selected Measure Name Company Selected Measure Name Leases Lessee, Operating Leases [Text Block] Common stock shares value reserved for future issuance Common Stock Capital Shares Value Reserved For Future Issuance Common stock, capital shares value reserved for future issuance. Shares issued Shares, Issued LIABILITIES, NONCONTROLLING INTEREST AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Finite Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Short-term investments, Available-for-sale, Adjusted Basis Debt Securities, Available-for-Sale, Amortized Cost, Current Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Investments Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Schedule of Gross Unrecognized Tax Benefits Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Contract liabilities included in deferred revenue Contract with Customer, Liability Exercise of stock options (in shares) Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Domestic Income (Loss) from Continuing Operations before Income Taxes, Domestic Sorrento Valley Owner (DE) LLC Sorrento Valley Owner (DE) LLC [Member] Sorrento Valley Owner (DE) LLC Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Executive Category: Executive Category [Axis] 2013 Plan Two Thousands Thirteen Incentive Plan [Member] Two thousands thirteen incentive plan. Number of RSUs Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Non-deductible compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Compensation, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Compensation, Percent Other Commitments [Table] Other Commitments [Table] Exercised (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Sales-related milestone payments Sales Related Milestone Payments Sales-related milestone payments. Level 1 Fair Value, Inputs, Level 1 [Member] Name Measure Name Patents Patents [Member] Name Forgone Recovery, Individual Name Gross increase for prior period tax positions Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Summary of Property and Equipment Property, Plant and Equipment [Table Text Block] Common Stock Equity Components [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Accrued expenses Increase (Decrease) in Accrued Liabilities Certificate of deposits Certificates of Deposit [Member] Common stock reserved for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Short-term investments, Available-for-sale, Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, Current Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, Current Lessee Lease Description [Table] Lessee, Lease, Description [Table] Asset Acquisition Asset Acquisition [Domain] Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Underlying Securities Award Underlying Securities Amount Collaboration and License agreements Collaboration and License Agreements [Member] Collaboration and license agreements. Entity Small Business Entity Small Business 2027 Finite-Lived Intangible Asset, Expected Amortization, Year Four Local Phone Number Local Phone Number Accounts receivable Increase (Decrease) in Accounts Receivable Number of distinct performance obligations Number Of Distinct Performance Obligations Number of distinct performance obligations. Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Percentage of commission to sales agent Percentage Of Commission On Aggregate Gross Proceeds From Sale Of Common Stock Percentage of commission on aggregate gross proceeds from sale of common stock. Interest per annum Additional Tenant Improvement Allowance, Interest Per Annum Additional Tenant Improvement Allowance, Interest Per Annum Commercial notes Commercial Notes [Member] Commercial Notes Measurement Frequency Measurement Frequency [Axis] Lease liabilities, net of current portion Operating Lease, Liability, Noncurrent Organization and Significant Accounting Policies Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Restricted cash Restricted Cash and Cash Equivalents, Current Retirement Plan Type [Domain] Retirement Plan Type [Domain] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Proceeds from the sale of future royalties Proceeds from Sale of Future Royalties Proceeds from Sale of Future Royalties Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Performance-Based Restricted Stock Units Restricted Stock Units, Performance-Based [Member] Restricted Stock Units, Performance-Based Retirement Benefits [Abstract] Retirement Benefits [Abstract] Income Statement Location [Axis] Income Statement Location [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Research and development Research and Development Expense (Excluding Acquired in Process Cost) Research Facility in San Diego Research Facility In San Diego [Member] Research Facility in San Diego. Development regulatory and sales milestones payments Development, regulatory and sales milestones payments Development Regulatory And Sales Milestones Payments Development regulatory and sales milestones payments. Summary of Maturities of Operating Lease Liabilities on an Undiscounted Basis Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Effect of dilutive securities (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Variable Interest Entity Consolidation, Variable Interest Entity, Policy [Policy Text Block] Victoria Vakiener [Member] Victoria Vakiener Other Performance Measure, Amount Other Performance Measure, Amount Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Schedule of Lease Assets and Liabilities and Lease Cost Lease, Cost [Table Text Block] Summary of Short-term, Long-term Investments and Marketable Securities Held To Maturity Securities And Marketable Securities Table [Table Text Block] Held to maturity securities and marketable securities. Long-term investments, Held to maturity, Fair Value Debt Securities, Held-to-Maturity, Fair Value, Noncurrent Contract assets Contract with Customer, Asset, after Allowance for Credit Loss, Current Research and development Research and Development Expense [Member] Additional tenant improvement allowance liability Additional Tenant Improvement Allowance Liability Additional Tenant Improvement Allowance Liability CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Potentially dilutive securities excluded from computation of diluted earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Award Type Award Type [Axis] Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Plan Name Plan Name [Domain] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Interest expense Interest Expense Unrecognized pre-tax compensation expense Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Fair Value Hierarchy and NAV Fair Value Hierarchy and NAV [Domain] ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Number of shares authorized (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized General and administrative expense General and Administrative Expense [Member] Total gross fixed assets Property, Plant and Equipment, Gross Weighted-Average Remaining Contractual Term, Outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Right-of-use assets obtained in exchange for amended operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Trading Arrangement: Trading Arrangement [Axis] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Less imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Provisions for Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] James Hamilton Terminated Plan [Member] James Hamilton Terminated Plan Entity File Number Entity File Number Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] 2029 and thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Summary of Share Activity Related to RSUs Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Lease liabilities Operating Lease, Liability, Current Prepaid expenses Prepaid Expense, Current Gross decrease for prior period tax positions Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Auditor Firm ID Auditor Firm ID Amortization expense Amortization of Intangible Assets Entity Shell Company Entity Shell Company 2026 Lessee, Operating Lease, Liability, to be Paid, Year Three Risk-free interest rate, minimum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Intangible assets, net Net Carrying Amount Finite-Lived Intangible Assets, Net Restatement Determination Date Restatement Determination Date Schedule of Company's Current Pipeline Schedule of Current Products [Table Text Block] Schedule of Current Products Accrued compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Gross increase for current period tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Janssen Janssen Pharmaceuticals Incorporation [Member] Janssen Pharmaceuticals, Incorporation. Counterparty Name Counterparty Name [Domain] Other Increase (Decrease) in Other Operating Liabilities Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Schedule of Shares of Common Stock and Preferred Stock Schedule of Stock by Class [Table Text Block] Cash, cash equivalents and restricted cash BEGINNING OR PERIOD END OF PERIOD Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Inducement Awards Inducement Awards [Member] Inducement Awards 2025 Lessee, Operating Lease, Liability, to be Paid, Year Two Schedule of Components of Loss Before Income Taxes Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Foreign Income (Loss) from Continuing Operations before Income Taxes, Foreign Variable lease cost Variable Lease, Cost Initial transaction price Initial Transaction Price Initial transaction price. Operating lease cost Operating Lease, Cost Weighted-average shares used in calculating Denominator: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Common stock, shares issued (in shares) Common Stock, Shares, Issued Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Proceeds from sales and maturities of investments Proceeds from Sale, Maturity and Collection of Investments Deferred revenue Contract liabilities Contract with Customer, Liability, Current Assumptions Used to Value Stock Options Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Security Exchange Name Security Exchange Name Total financial assets Assets, Fair Value Disclosure Stock-Based Compensation Share-Based Payment Arrangement [Policy Text Block] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Collaboration and License Agreements Collaborative Arrangement Disclosure [Text Block] Audit Information [Abstract] Audit Information Employee Stock Option Employee Stock Option [Member] Investments Investment, Policy [Policy Text Block] Discretionary match percentage Defined Contribution Plan, Employer Matching Contribution, Percent of Match Commercial milestone payments at first commercial sale Commercial Milestone Payments At First Commercial Sale Commercial milestone payments at first commercial sale. Weighted average period to recognize pre-tax compensation expense Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Maximum Maximum [Member] Document Type Document Type Tabular List, Table Tabular List [Table Text Block] Federal Domestic Tax Authority [Member] Short-term lease cost Short-Term Lease, Cost Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Additional remaining development regulatory and sales milestones payments Additional Remaining Development Regulatory And Sales Milestones Payments Additional remaining development regulatory and sales milestones payments. Chief Executive Officer Chief Executive Officer [Member] 2021 Plan Two Thousand Twenty One Incentive Plan [Member] Two thousand twenty one incentive plan. Stock-Based Compensation Share-Based Payment Arrangement [Text Block] Federal Current Federal Tax Expense (Benefit) Net increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Proceeds from investment in joint venture Proceeds from upfront capital Proceeds from Contributed Capital Weighted- Average Exercise Price Per Share Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Operating loss carryforwards Operating Loss Carryforwards Deferred revenue Deferred Tax Assets, Deferred Income State Deferred State and Local Income Tax Expense (Benefit) Schedule of Finite-Lived Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Other liabilities Other Liabilities, Current Income Statement [Abstract] Income Statement [Abstract] Number of shares forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Leasehold improvements Leasehold Improvements, Gross Security12b Title Title of 12(b) Security Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Money market instruments Cash and Cash Equivalents, Fair Value Disclosure Visirna Therapeutics, Inc. Visirna Therapeutics, Inc. [Member] Visirna Therapeutics, Inc. Milestone payment Milestone Payment Earned Milestone payment earned. Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] 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 Other current assets Other Assets, Current Class Of Stock [Line Items] Class of Stock [Line Items] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Entity Tax Identification Number Entity Tax Identification Number Other Commitments [Domain] Other Commitments [Domain] State taxes Deferred Tax Liabilities State Taxes Amount of deferred tax liability attributable to taxable temporary differences from state tax deductions. Total Lease, Cost Schedule Of Held To Maturity Securities And Marketable Securities [Table] Schedule Of Held To Maturity Securities And Marketable Securities [Table] Schedule of held to maturity securities and marketable securities. Statistical Measurement [Axis] Statistical Measurement [Axis] Capitalized research and development Deferred Tax Assets In Process Research And Development Cost Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs. Operating loss carryforwards not subject to expiration Operating Loss Carryforwards, Not Subject To Expiration Operating Loss Carryforwards, Not Subject To Expiration Financial Instrument [Axis] Financial Instrument [Axis] Entity Interactive Data Current Entity Interactive Data Current Olpasiran Agreement Olpasiran Agreement [Member] Olpasiran agreement. Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Change in unrecognized tax benefits expected Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Total Shareholder Return Amount Total Shareholder Return Amount Entity Common Stock Shares Outstanding Entity Common Stock, Shares Outstanding Intangible Assets subject to amortization Goodwill and Intangible Assets, Policy [Policy Text Block] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Foreign Deferred Foreign Income Tax Expense (Benefit) Fair Value Hierarchy and NAV Fair Value Hierarchy and NAV [Axis] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Milestone payment receivable upon achievement of phase two and first patient dosed in phase three Milestone Payment Receivable Upon Achievement Of Phase Two And First Patient Dosed In Phase Three Milestone payment receivable upon achievement of phase two and first patient dosed in phase three. Amount insured in FDIC per account Cash, FDIC Insured Amount Accumulated deficit Retained Earnings (Accumulated Deficit) Measure: Measure [Axis] Drug Manufacturing Facility Drug Manufacturing Facility [Member] Drug manufacturing facility. Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Common stock - restricted stock units vesting (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Name Outstanding Recovery, Individual Name Revenue Recognition Revenue from Contract with Customer [Policy Text Block] 2004 Equity Incentive Plan, 2013 Equity Incentive Plan, 2021 Equity Incentive Plan and Inducement Grants Two Thousand Four Equity Incentive Plan Two Thousand Thirteen Equity Incentive Plan Two Thousand Twenty One Equity Incentive Plan And Inducement Grants [Member] Two thousand four equity incentive plan two thousand thirteen equity incentive plan Two thousand twenty one equity incentive plan and inducement grants. Lease liabilities Deferred Tax Assets Right Of Use Assets Or Lease Liabilities Deferred tax assets right of use assets/ lease liabilities. Collaboration And License Agreements [Abstract] Collaboration And License Agreements [Abstract] Collaboration and license agreements. Entity Incorporation State Country Code Entity Incorporation, State or Country Code Deferred tax liabilities: Deferred Tax Liabilities, Net [Abstract] Current assets: Assets, Current [Abstract] Leases [Abstract] Leases [Abstract] Other Commitments [Line Items] Other Commitments [Line Items] Components of the Net Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Entity Address, State or Province Entity Address, State or Province Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Counterparty Name Counterparty Name [Axis] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] William Waddill [Member] William Waddill 2024 Finite-Lived Intangible Asset, Expected Amortization, Year One Schedule Of Held To Maturity Securities And Marketable Securities [Line Items] Schedule Of Held To Maturity Securities And Marketable Securities [Line Items] Schedule of held to maturity securities and marketable securities. Operating cash flows from operating leases Operating Lease, Payments Unrealized losses on available-for-sale securities OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Organization And Significant Accounting Policies [Table] Organization And Significant Accounting Policies [Table] Organization and significant accounting policies. PEO PEO [Member] Concentration of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Auditor Location Auditor Location Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] California CALIFORNIA Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Sale of Stock Sale of Stock [Axis] Permanent and other items Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Customer [Domain] Customer [Domain] Number of options to renew Number Of Options To Renew Number of options to renew. Takeda Takeda Pharmaceuticals United States Of America Incorporated [Member] Takeda Pharmaceuticals United States of America Incorporated. Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Maximum state income tax credits under agreement Tax Increment Financing Award, Maximum State Income Tax Credits Under Agreement Tax Increment Financing Award, Maximum State Income Tax Credits Under Agreement Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Total operating lease liabilities Operating Lease, Liability Interest in joint venture Noncontrolling Interest, Increase from Subsidiary Equity Issuance Summary of Awards Outstanding Share-Based Payment Arrangement, Activity [Table Text Block] Total current tax Current Income Tax Expense (Benefit) Volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Asset Acquisition Asset Acquisition [Axis] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Horizon Horizon Therapeutics Ireland D A C [Member] Horizon Therapeutics Ireland DAC. Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Employee benefits costs Defined Contribution Plan, Cost Measurement Frequency Measurement Frequency [Domain] Shares reserve for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Property and Equipment Property, Plant and Equipment Disclosure [Text Block] All Executive Categories All Executive Categories [Member] Deferred revenue, net of current portion Contract with Customer, Liability, Noncurrent Long-term liabilities: Liabilities, Noncurrent [Abstract] Title of Individual [Axis] Title of Individual [Axis] Liability Related to the Sale of Future Royalties Liability Related To The Sale Of Future Royalties [Text Block] Liability Related To The Sale Of Future Royalties Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Plan Name Plan Name [Axis] James Hamilton [Member] James Hamilton Lease Assets and Liabilities Assets and Liabilities, Lessee [Abstract] Upfront milestone payment received Upfront Milestone Payment Received Upfront milestone payment received. Long-Lived Tangible Asset Long-Lived Tangible Asset [Domain] Earnings Per Share [Abstract] Milestone payments Milestone Payments Milestone payments. Common stock, $0.001 par value: Authorized 290,000 shares; issued and outstanding 107,312 and 105,960 shares Common Stock, Value, Issued U.S. government bonds US Government Debt Securities [Member] General and administrative General and Administrative Expense Cash received for amounts included in the measurement of lease liabilities: Cash Flow, Operating Activities, Lessee, Cash Received For Amounts Included In Measurement Of Lease Liabilities [Abstract] Cash Flow, Operating Activities, Lessee, Cash Received For Amounts Included In Measurement Of Lease Liabilities Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] State Current State and Local Tax Expense (Benefit) Tracie Oliver [Member] Tracie Oliver Total current assets Assets, Current Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Schedule Of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Receivables included in accounts receivable Accounts Receivable, after Allowance for Credit Loss All Individuals All Individuals [Member] Supplementary disclosures: Supplemental Cash Flow Information [Abstract] Cash paid for amounts included in the measurement of lease liabilities: Cash Flow, Operating Activities, Lessee [Abstract] Unrecognized tax benefits, penalties accrued Unrecognized Tax Benefits, Income Tax Penalties Accrued Other, net Other Nonoperating Income (Expense) Entity Filer Category Entity Filer Category Computers, software, office equipment and furniture Computers Software Office Equipment And Furniture Gross Computers, software, office equipment and furniture gross. Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Statement [Table] Statement [Table] Current Fiscal Year End Date Current Fiscal Year End Date Earnings per Share Earnings Per Share, Policy [Policy Text Block] Liability Related To The Sale Of Future Royalties [Abstract] Liability Related To The Sale Of Future Royalties Summary of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Held-to-maturity debt securities Debt Securities, Held-to-Maturity, Fair Value Beginning balance of unrecognized tax benefits Ending balance of unrecognized tax benefits Unrecognized Tax Benefits Income Tax Authority [Axis] Income Tax Authority [Axis] Novartis Novartis [Member] Novartis. PEO Name PEO Name Volatility, minimum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Short-term investments, Held to maturity, Gross Unrealized Losses Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss, Current Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss, Current State income taxes, net of federal tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent 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 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Five Cancelled (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Tax credits Deferred Tax Assets, Tax Credit Carryforwards Outside Of Equity Compensation Plans Outside Of Equity Compensation Plans [Member] Outside of equity compensation plans. Net increase (decrease) in cash and investments Increase (Decrease) In Cash And Investments Increase decrease in cash and investments. Stock compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost License and Co-Funding Agreement License And Co Funding Agreement [Member] License and co-funding agreement. Net cash provided by (used in) operating activities Net Cash Provided by (Used in) Operating Activities Aggregate Intrinsic Value, Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Schedule of Intangible Assets Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Available-for-sale securities, at fair value Short-term investments, Available-for-sale, Fair Value Debt Securities, Available-for-Sale, Current Planned area of site (in sq ft) Area of Land Short-term investments, Held to maturity, Fair Value Debt Securities, Held-to-Maturity, Fair Value, Current Depreciation and amortization expense for property and equipment Depreciation, Depletion and Amortization Organization And Significant Accounting Policies [Line Items] Organization And Significant Accounting Policies [Line Items] Organization and significant accounting policies. ATM Agreement At The Market Agreement [Member] At-the-market agreement. Corporate Headquarters In Pasadena Corporate Headquarters In Pasadena [Member] Corporate Headquarters in Pasadena Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Total Arrowhead Pharmaceuticals, Inc. stockholders' equity Equity, Attributable to Parent Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Schedule Of Finite Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Valuation allowance Valuation allowance Deferred Tax Assets, Valuation Allowance Number of distinct bundle Number Of Distinct Bundle Number of distinct bundle. Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Royalty payment threshold Royalty Payment Threshold Royalty Payment Threshold Amount intended to invest for buildout of facilities Amount Intended To Invest For Buildout Of Facilities Amount intends to invest for buildout of facilities. Finite-Lived Intangible Assets, Major Class Name Finite-Lived Intangible Assets, Major Class Name [Domain] Foreign currency translation adjustments Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Facilities Facilities [Member] Facilities. Schedule Of Stock By Class [Table] Schedule of Stock by Class [Table] Expected term (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Subsequent Events [Abstract] Subsequent Events [Abstract] Loss before income tax expense and noncontrolling interest Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Net loss per share attributable to Arrowhead Pharmaceuticals, Inc.: Earnings Per Share Reconciliation [Abstract] Long-Lived Tangible Asset Long-Lived Tangible Asset [Axis] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Basis of Presentation and Use of Estimates Basis Of Presentation And Use Of Estimates Policy [Policy Text Block] Basis of presentation and use of estimates. Non-cash interest expense on liability related to the sale of future royalties Non-Cash Interest Expense, Liability Related to Sale of Future Royalties Non-Cash Interest Expense, Liability Related to Sale of Future Royalties Level 2 Fair Value, Inputs, Level 2 [Member] Entity Emerging Growth Company Entity Emerging Growth Company Royalty Pharma Agreement Royalty Pharma Agreement [Member] Royalty Pharma Agreement Total gross deferred tax assets Deferred Tax Assets, Gross Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Common Stock Purchase Agreement Common Stock Purchase Agreement [Member] Common stock purchase agreement. Document Fiscal Period Focus Document Fiscal Period Focus Operating cash flows from operating leases Operating Lease, Cash Received For Amounts Included In Measurement Of Lease Liabilities Operating Lease, Cash Received For Amounts Included In Measurement Of Lease Liabilities 2024 Lessee, Operating Lease, Liability, to be Paid, Year One Useful Lives Finite-Lived Intangible Asset, Useful Life Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] 2027 Lessee, Operating Lease, Liability, to be Paid, Year Four Title Trading Arrangement, Individual Title 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 Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Common Stock Common Stock [Member] Individual: Individual [Axis] Verona Technology Park Verona Technology Park [Member] Verona technology park. Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Earnings Per Share Earnings Per Share [Text Block] Income Statement Location [Domain] Income Statement Location [Domain] Amgen Amgen Incorporated [Member] Amgen Incorporated. Document Fiscal Year Focus Document Fiscal Year Focus Geographical Geographical [Domain] Total noncontrolling interest and stockholders' equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Lease term Lessee, Operating Lease, Term of Contract Income tax expense related to uncertain tax positions Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Minimum Minimum [Member] Property and equipment, net Property and equipment, net Property, Plant and Equipment, Net Summarized Information about Stock Options Share-Based Payment Arrangement, Option, Activity [Table Text Block] Exercise Price Award Exercise Price Finite-Lived Intangible Assets by Major Class Finite-Lived Intangible Assets by Major Class [Axis] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] ASSETS Assets [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Operating lease, net Increase (Decrease) in Operating Lease Liability Deferred tax assets: Deferred Tax Assets, Net [Abstract] Other Deferred Tax Assets, Other Net loss including noncontrolling interest Net loss Net loss including noncontrolling interest Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Income Taxes Paid Income Taxes Paid, Net Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Retirement Plan Type [Axis] Retirement Plan Type [Axis] Lessee Lease Description [Line Items] Lessee, Lease, Description [Line Items] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Operating loss carryforwards subject to expiration Operating Loss Carryforwards, Subject To Expiration Operating Loss Carryforwards, Subject To Expiration Accumulated Deficit Retained Earnings [Member] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Total Liabilities, Noncontrolling Interest and Stockholders' Equity Liabilities and Equity Marketable debt securities, Adjusted Basis Debt Securities, Available-for-Sale, Amortized Cost Other income (expense): Nonoperating Income (Expense) [Abstract] Other assets Other Assets, Noncurrent Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Basic (in dollars per share) Earnings Per Share, Basic Right-of-use assets Operating Lease, Right-of-Use Asset Unrecognized pre-tax compensation expense Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Accounting Policies [Abstract] Accounting Policies [Abstract] Milestone payment receivable upon FDA approval Milestone Payment Receivable Upon FDA Approval Milestone Payment Receivable Upon FDA Approval Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Sale of Stock Sale of Stock [Domain] Risk-free interest rate, maximum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Foreign Current Foreign Tax Expense (Benefit) Volatility, maximum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum Net deferred tax assets (liabilities) Deferred Tax Assets, Net Intrinsic value of options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Milestone payment receivable upon achievement of enrollment in phase 3 clinical trial Milestone Payment Receivable Upon Achievement of Enrollment in Phase 3 Clinical Trial Milestone Payment Receivable Upon Achievement of Enrollment in Phase 3 Clinical Trial Arrangement Duration Trading Arrangement Duration Entity Address, City or Town Entity Address, City or Town Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Impairment Finite-Lived Intangible Assets, Impairment Finite-Lived Intangible Assets, Impairment Held-to-maturity securities, at amortized cost Long-term investments, Held to maturity, Adjusted Basis Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Noncurrent State income tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Amount Total long-term liabilities Liabilities, Noncurrent Document Transition Report Document Transition Report Award Timing Predetermined Award Timing Predetermined [Flag] Milestone payments Milestone Payment Received Milestone payment received. 2004 Plan Two Thousands Four Equity Incentive Plan [Member] Two thousands four equity incentive plan. Termination Date Trading Arrangement Termination Date Research equipment Research Equipment Gross Research equipment gross. Accounts payable Increase (Decrease) in Accounts Payable Common stock, shares authorized (in shares) Common Stock, Shares Authorized Available-for-sale debt securities Debt Securities, Available-for-Sale Percentage of eligible to receive tiered royalties on net sales Percentage Of Eligible To Receive Tiered Royalties On Net Sales Percentage of eligible to receive tiered royalties on net sales. Employee Contributions up to 3% Employee Contributions Up To Three Percent [Member] Employee contributions up to three percent. Land purchased (in acres) Number Of Acres Of Land Purchased Number of acres of land purchased. Entity Public Float Entity Public Float Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Employee Contributions Next 2% Employee Contribution Next Two Percent [Member] Employee contribution next two percent. Adjustments to reconcile net loss to net cash flow from operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] All Trading Arrangements All Trading Arrangements [Member] All Adjustments to Compensation All Adjustments to Compensation [Member] Award Timing Disclosures [Line Items] Cash and Cash Equivalents and Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Total (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Options And Equity Instruments Other Than Options, Outstanding Share-Based Compensation Arrangement By Share-Based Payment Award, Options And Equity Instruments Other Than Options, Outstanding Title of Individual [Domain] Title of Individual [Domain] Compensation Amount Outstanding Recovery Compensation Amount Net loss (gain) from investments Gain (Loss) on Investments Long-term investments, Held to maturity, Gross Unrealized Losses Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss, Noncurrent Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss, Noncurrent Other Commitments [Axis] Other Commitments [Axis] Mauro Ferrari [Member] Mauro Ferrari 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 Common stock - restricted stock units vesting Stock Issued During Period, Value, Restricted Stock Award, Gross Right-of-use assets Deferred Tax Liabilities, Leasing Arrangements Total deferred tax Deferred Income Tax Expense (Benefit) Proceeds from the exercises of stock options Proceeds from Stock Options Exercised Collaborative Arrangement Collaborative Arrangement, Accounting Policy [Policy Text Block] GSK Glaxosmithkline Intellectual Property Limited [Member] Glaxosmithkline Intellectual Property Limited. Income Taxes Income Tax, Policy [Policy Text Block] Document Financial Statement Error Correction [Flag] Document Financial Statement Error Correction [Flag] 2026 Finite-Lived Intangible Asset, Expected Amortization, Year Three Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Colorado Owner, LLC Colorado Owner L L C [Member] Colorado Owner, LLC. Municipal securities Municipal Bonds [Member] Short-term investments, Available-for-sale, Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, Current Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, Current Percentage of compensation Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Insider Trading Arrangements [Line Items] Total Income (Loss) Attributable to Parent, before Tax Number of agreements Number Of Agreements Number of agreements. Aggregate Intrinsic Value, Outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Short-term investments, Held to maturity, Gross Unrealized Gains Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain, Current Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain, Current JNJ-3989 Agreement J N J3989 A R O H B V Agreement [Member] JNJ-3989 (ARO-HBV) Agreement. Entity Registrant Name Entity Registrant Name Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Award Timing Method Award Timing Method [Text Block] 2025 Finite-Lived Intangible Asset, Expected Amortization, Year Two Adjustment to Compensation, Amount Adjustment to Compensation Amount Maximum additional tenant improvement allowance Maximum Additional Tenant Improvement Allowance Maximum Additional Tenant Improvement Allowance Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Noncontrolling interest Equity, Attributable to Noncontrolling Interest Tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Percent Auditor Name Auditor Name Document Period End Date Document Period End Date Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Adoption Date Trading Arrangement Adoption Date Less: Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Fair Value Measurements for Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Weighted-Average Exercise Price Per Share, Exercisable (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price ARO-ENaC and ARO-HIF2 Candidates A R O E Nac And A R O H I F2 Candidates [Member] ARO-ENac and ARO-HIF2 Candidates. Entity Central Index Key Entity Central Index Key Contingent liabilities Loss Contingency Accrual Stock-based compensation expense Share-Based Payment Arrangement, Expense Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Income tax expense Income tax provision Income Tax Expense (Benefit) Income Tax Authority [Domain] Income Tax Authority [Domain] Accrued payroll and benefits Employee-related Liabilities, Current Fair Value Measurements Fair Value Disclosures [Text Block] Name Trading Arrangement, Individual Name Milestone payment receivable upon receipt of royalty payments Milestone Payment Receivable, Upon Receipt Of Royalty Payments Milestone Payment Receivable, Upon Receipt Of Royalty Payments Schedule of Revenue Disaggregation of Revenue [Table Text Block] Equity [Abstract] Equity [Abstract] Weighted-average remaining lease term (in years) Operating Lease, Weighted Average Remaining Lease Term Revenue Revenues Revenue from Contract with Customer, Excluding Assessed Tax Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Amendment Flag Amendment Flag Intangible Assets Intangible Assets Disclosure [Text Block] Money market instruments Money Market Funds [Member] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Ken Myszkowski [Member] Ken Myszkowski Intangible assets Deferred Tax Assets, Goodwill and Intangible Assets Weighted-average discount rate Operating Lease, Weighted Average Discount Rate, Percent License Licensing Agreements [Member] Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Comprehensive loss Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest James Hamilton August 2023 Plan [Member] James Hamilton August 2023 Plan Property and equipment, useful life Property, Plant and Equipment, Useful Life Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Diluted (in shares) Weighted-average diluted shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Schedule of Receivables and Contract Liabilities Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Operating expenses: Operating Expenses [Abstract] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Company Selected Measure Amount Company Selected Measure Amount Additional paid-in capital Additional Paid in Capital, Common Stock Additional Paid-In Capital Additional Paid-in Capital [Member] Document Annual Report Document Annual Report Milestone payment receivable Milestone Payment Receivable Milestone Payment Receivable Cancelled (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Lease Cost Lease, Cost [Abstract] Total Assets Assets Name Awards Close in Time to MNPI Disclosures, Individual Name JJDC Johnson And Johnson Innovation J J D C Incorporation [Member] Johnson and Johnson Innovation-JJDC, Incorporation. Equity award value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Granted in Period, Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Granted in Period, Fair Value Cover [Abstract] Cover [Abstract] Held-to-maturity securities, at amortized cost Short-term investments, Held to maturity, Adjusted Bases Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Current Subsequent Events Subsequent Events [Text Block] Stock-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Fair Value, Measurements, Recurring Fair Value, Recurring [Member] 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 Non-NEOs Non-NEOs [Member] Total Lessee, Operating Lease, Liability, to be Paid Horizon License Agreement Horizon License Agreement [Member] Horizon License Agreement Net unrealized gain (loss) on held-to-maturity securities OCI, Debt Securities, Available-for-Sale, Transfer from Held-to-Maturity, Gain (Loss), before Adjustment and Tax Employee Benefit Plans Compensation and Employee Benefit Plans [Text Block] Total operating expenses Operating Expenses CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Non-PEO NEO Non-PEO NEO [Member] Operating lease renewal term Lessee, Operating Lease, Renewal Term Equity Component Equity Component [Domain] Adjustment to Compensation: Adjustment to Compensation [Axis] State State and Local Jurisdiction [Member] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards Basic (in shares) Weighted-average basic shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Entity Current Reporting Status Entity Current Reporting Status Operating loss Operating Income (Loss) Fixed assets Deferred Tax Liabilities, Property, Plant and Equipment Patrick O'Brien [Member] Patrick O'Brien Laboratory And Office Facility Laboratory And Office Facility [Member] Laboratory and office facility. Total gross deferred tax liability Deferred Tax Liabilities, Gross Consolidated Entities [Domain] Consolidated Entities [Domain] Research Facility in Madison Research Facility In Madison [Member] Research facility in Madison. Other comprehensive loss, net of tax: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Long-term investments, Held to maturity, Gross Unrealized Gains Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain, Noncurrent Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain, Noncurrent Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Statement [Line Items] Statement [Line Items] Unrecognized tax benefits, interest accrued Unrecognized Tax Benefits, Interest on Income Taxes Accrued Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Noncontrolling interest and stockholders' equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Non- controlling Interest Noncontrolling Interest [Member]