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Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Debt instrument term Debt Instrument, Term 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Four All Individuals All Individuals [Member] Buildings Building [Member] PEO PEO [Member] Income Tax Disclosure [Abstract] Name Trading Arrangement, Individual Name Principal repayment schedule through fifth year Long-Term Debt, Maturity, Through Five Long-Term Debt, Maturity, Through Five At The Market Agreement At The Market Agreement [Member] At-the-market agreement. Other, net Other Nonoperating Income (Expense) Corporate Headquarters In Pasadena Corporate Headquarters In Pasadena [Member] Corporate Headquarters in Pasadena Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Number of distinct bundle Number Of Distinct Bundle Number of distinct bundle. Unrecognized pre-tax compensation expense Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Royalty payment threshold Royalty Payment Threshold Royalty Payment Threshold Schedule of Line of Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] CASH, CASH EQUIVALENTS AND RESTRICTED CASH: Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract] 2025 (remainder) Long-Term Debt, Maturity, Remainder of Fiscal Year Property, plant and equipment, reclassification Property, Plant and Equipment, Transfers and Changes Facilities Facilities [Member] Facilities. Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Shares reserve for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance 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] Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Non-cash interest expense on liability related to the sale of future royalties Non-cash interest expense recognized Non-Cash Interest Expense, Liability Related To Sale Of Future Royalties Non-Cash Interest Expense, Liability Related To Sale Of Future Royalties Total long-term liabilities Liabilities, Noncurrent Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Local Phone Number Local Phone Number Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Royalty Pharma Agreement Royalty Pharma Agreement [Member] Royalty Pharma Agreement Sarepta Sarepta Therapeutics, Inc [Member] Sarepta Therapeutics, Inc Total operating expenses Operating Expenses Upfront payment Proceeds From Collaboration Arrangements Proceeds From Collaboration Arrangements Schedule of Share Activity Related to RSUs Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Schedule of Interest Expense Recognized Related To Credit Facility Summary Of Interest Expense Recognized Related To Credit Facility [Table Text Block] Summary Of Interest Expense Recognized Related To Credit Facility Upfront payment received Upfront Payment Received, Liability Related To Sale Of Future Royalties Upfront Payment Received, Liability Related To Sale Of Future Royalties Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] 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 Long-term liabilities: Liabilities, Noncurrent [Abstract] PEO Total Compensation Amount PEO Total Compensation Amount Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Schedule of Accrued Expenses Schedule of Accrued Liabilities [Table Text Block] Income Statement Location [Axis] Statement of Income Location, Balance [Axis] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Debt Disclosure [Abstract] Common Stock Common Stock [Member] Measure: Measure [Axis] Amgen Incorporated Amgen Incorporated [Member] Amgen Incorporated. Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Common stock issued, net of offering costs (in shares) Stock Issued During Period, Shares, New Issues Line of Credit Line of Credit [Member] Entity Emerging Growth Company Entity Emerging Growth Company Market capitalization threshold Debt Instrument, Covenant, Market Capitalization, Threshold Debt Instrument, Covenant, Market Capitalization, Threshold Entity Central Index Key Entity Central Index Key General and administrative expense General and Administrative Expense [Member] Lessee Lease Description [Table] Lessee, Lease, Description [Table] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Stockholders' Equity Equity [Text Block] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Equity Component [Domain] Equity Component [Domain] Financial Instrument [Axis] Financial Instrument [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Stock-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Repayments of debt, percentage of milestone payment Repayment Of Debt, Percentage Of Milestone Payment Repayment Of Debt, Percentage Of Milestone Payment Entity Shell Company Entity Shell Company Number of collaboration programs Number Of Collaboration Programs Number Of Collaboration Programs Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Title Trading Arrangement, Individual Title 2030 and thereafter Lessee Operating Lease Liability Payments Due Year Five And After Year Five Lessee operating lease liability payments due year five and after year five. Statement [Table] Statement [Table] Total interest expense Interest Expense, Debt Milestone payment receivable upon FDA approval Milestone Payment Receivable, Upon FDA Approval Milestone Payment Receivable, Upon FDA Approval Measurement Frequency Measurement Frequency [Domain] Counterparty Name [Axis] Counterparty Name [Axis] Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] After two to three years Debt Securities, Available-For-Sale, Fair Value, Maturity, Allocated And Single Maturity Date, After Year Two Through Three Debt Securities, Available-For-Sale, Fair Value, Maturity, Allocated And Single Maturity Date, After Year Two Through Three City Area Code City Area Code Current liabilities: Liabilities, Current [Abstract] 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 Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Level 1 Fair Value, Inputs, Level 1 [Member] Impairment Finite-Lived Intangible Assets, Impairment Finite-Lived Intangible Assets, Impairment Foreign currency translation adjustments Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Accrued expenses Increase (Decrease) in Accrued Liabilities Estimated variable consideration Collaboration Arrangement, Variable Consideration Collaboration Arrangement, Variable Consideration Line of credit facility, remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Number of Options Outstanding, Exercisable (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number 2028 Long-Term Debt, Maturity, Year Three Credit facility, net of current portion Long-Term Debt, Excluding Current Maturities 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] 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. Income Taxes Income Tax Disclosure [Text Block] Organization and Significant Accounting Policies Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] 2029 Lessee, Operating Lease, Liability, to be Paid, Year Four Earnings Per Share [Abstract] Equity [Abstract] Equity [Abstract] Accumulated deficit Retained Earnings (Accumulated Deficit) General and administrative General and Administrative Expense 2027 Long-Term Debt, Maturity, Year Two Organization, Consolidation and Presentation of Financial Statements [Abstract] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Equity Awards Adjustments Equity Awards Adjustments [Member] Weighted-average discount rate Operating Lease, Weighted Average Discount Rate, Percent Total operating lease liabilities (includes current portion) Operating Lease, Liability Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Underlying Securities Award Underlying Securities Amount Investments Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [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 Debt instrument, covenant, minimum liquidity cash, cash equivalents and investments Debt Instrument, Covenant, Minimum Liquidity If Capitalization Is Above Threshold Debt Instrument, Covenant, Minimum Liquidity If Capitalization Is Above Threshold Credit Facility [Axis] Credit Facility [Axis] Amendment Flag Amendment Flag Entity Registrant Name Entity Registrant Name Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Depreciation and amortization expense for property and equipment Depreciation, Depletion and Amortization Fixed consideration Fixed consideration Collaboration Arrangement, Fixed Consideration Collaboration Arrangement, Fixed Consideration Intangible Assets Intangible Assets Disclosure [Text Block] Fair Value as of Grant Date Award Grant Date Fair Value Level 2 Fair Value, Inputs, Level 2 [Member] Shares of common stock issued (in shares) Sale of Stock, Number of Shares Issued in Transaction Fair Value Hierarchy and NAV Fair Value Hierarchy and NAV [Domain] Noncontrolling interest and stockholders’ equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Geographical [Domain] Geographical [Domain] GSK Glaxosmithkline Intellectual Property Limited [Member] Glaxosmithkline Intellectual Property Limited. Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Schedule of Revenue Disaggregation of Revenue [Table Text Block] Common stock issued, net of offering costs Stock Issued During Period, Value, New Issues Computers and software Computer And Software [Member] Computer And Software Colorado Owner, LLC Colorado Owner L L C [Member] Colorado Owner, LLC. Entity Address, Postal Zip Code Entity Address, Postal Zip Code Current investments, Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, Current Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, Current Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Schedule of Share-Based Payment Arrangement, Expensed Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Restatement Determination Date: Restatement Determination Date [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Number of agreements Number Of Agreements Number of agreements. Title of 12(b) Security Title of 12(b) Security Common stock, $0.001 par value: Authorized 290,000 shares; issued and outstanding 138,062 and 124,376 shares Common Stock, Value, Issued Sarepta Collaboration Agreement Sarepta Collaboration Agreement [Member] Sarepta Collaboration Agreement Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Finite Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] 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 CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Credit facility, net of current portion Long-Term Line of Credit, Noncurrent Proceeds from sales and maturities of investments Proceeds from Sale, Maturity and Collection of Investments Useful life Property, Plant and Equipment, Useful Life Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Basic (in dollars per share) Basic net income (loss) per share (in dollars per share) Earnings Per Share, Basic Accounts payable Increase (Decrease) in Accounts Payable Proceeds from the issuance of common stock, net of offering costs Proceeds from Issuance of Common Stock Operating cash flows from operating leases Operating Lease, Payments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Amount intends to invest for buildout of the facilities Amount Intends To Invest For Buildout Of Facilities Amount intends to invest for buildout of facilities. Visirna ESOP Visirna ESOP [Member] Visirna ESOP Capital expenditures included in accrued expenses Capital Expenditures Incurred but Not yet Paid Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Milestone payment receivable upon receipt of royalty payments Milestone Payment Receivable, Upon Receipt Of Royalty Payments Milestone Payment Receivable, Upon Receipt Of Royalty Payments Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Schedule Of Stock By Class [Table] Stock, Class of Stock [Table] Total current liabilities Liabilities, Current 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] Total Assets Assets Collaborative Arrangement and Arrangement Other than Collaborative Collaborative Arrangement and Arrangement Other than Collaborative [Table Text Block] 2026 Finite-Lived Intangible Asset, Expected Amortization, Year One Long-term line of credit Long-Term Line of Credit Christopher Anzalone [Member] Christopher Anzalone Liability related to the sale of future royalties, interest rate Liability, Sale Of Future Royalties, Interest Rate Liability, Sale Of Future Royalties, Interest Rate Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Commitments and contingencies (Note 7) Commitments and Contingencies Ken Myszkowski [Member] Ken Myszkowski Termination Date Trading Arrangement Termination Date Warrant exercise price (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights 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] 2027 Lessee, Operating Lease, Liability, to be Paid, Year Two 2026 Long-Term Debt, Maturity, Year One Stock-Based Compensation Share-Based Payment Arrangement [Text Block] Entity Address, City or Town Entity Address, City or Town Sarepta Sarepta [Member] Sarepta Debt Instrument [Axis] Debt Instrument [Axis] Schedule of Summarized Information about Stock Options Share-Based Payment Arrangement, Option, Activity [Table Text Block] Intrinsic value of options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Collaboration agreement termination notice period prior to any regulatory approval of a licensed product Collaboration Arrangement, Termination Notice Period Prior To Regulatory Approval Collaboration Arrangement, Termination Notice Period Prior To Regulatory Approval Ken Myszkowski 2024 Plan [Member] Ken Myszkowski 2024 Plan Stock-based compensation expense Share-Based Payment Arrangement, Expense Net income (loss) attributable to Arrowhead Pharmaceuticals, Inc. Net income (loss) attributable to Arrowhead Pharmaceuticals, Inc. Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Other Commitments [Table] Other Commitments [Table] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Schedule of Finite-Lived Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Warrants purchase price (in dollars per share) Class of Warrant or Right, Purchase Price of Warrants or Rights Class of Warrant or Right, Purchase Price of Warrants or Rights Accrued capital expenditures Accrued Capital Expenditure, Current Accrued Capital Expenditure, Current Milestone payment receivable Milestone Payment Receivable Milestone Payment Receivable Entity File Number Entity File Number Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Document Fiscal Year Focus Document Fiscal Year Focus Non- controlling Interest Noncontrolling Interest [Member] Income Statement [Abstract] Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Weighted-average shares used in calculating Denominator: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Entity Address, Address Line Two Entity Address, Address Line Two Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 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 Total financial assets Assets, Fair Value Disclosure Lease term Lessee, Operating Lease, Term of Contract Other Other Accrued Liabilities, Current Name Forgone Recovery, Individual Name Aggregate Intrinsic Value, Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value 2025 (remainder) Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Weighted-average remaining lease term (in years) Operating Lease, Weighted Average Remaining Lease Term Document Period End Date Document Period End Date Sale of Stock [Axis] Sale of Stock [Axis] 2030 and thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Four Finite-Lived Intangible Asset, Expected Amortization, after Year Four Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Total Lessee, Operating Lease, Liability, to be Paid Ken Myszkowski 2025 Plan [Member] Ken Myszkowski 2025 Plan 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 Cancelled or expired (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period Insider Trading Arrangements [Line Items] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Balance Sheet Accounts Supplemental Balance Sheet Disclosures [Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Schedule of Shares of Common Stock and Preferred Stock Schedule of Stock by Class [Table Text Block] 2028 Lessee, Operating Lease, Liability, to be Paid, Year Three PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Adjustment to Compensation: Adjustment to Compensation [Axis] GSK-HBV Agreement GSK-HBV Agreement [Member] GSK-HBV Agreement Net loss attributable to noncontrolling interest, net of tax Net Income (Loss) Attributable to Noncontrolling Interest Document Transition Report Document Transition Report Document Quarterly Report Document Quarterly Report Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Customer [Domain] Customer [Domain] Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Current Reporting Status Entity Current Reporting Status Laboratory and Office Facility Laboratory And Office Facility [Member] Laboratory and office facility. Accumulated Deficit Retained Earnings [Member] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Asset Acquisition Asset Acquisition [Domain] Basic (in shares) Weighted-average basic shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Research Facility in Madison Research Facility In Madison [Member] Research facility in Madison. Total noncontrolling interest and stockholders’ equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Amortization of debt discount and issuance costs Amortization of Debt Issuance Costs and Discounts Restricted stock units Restricted Stock Units (RSUs) [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Purchases of investments Payments to Acquire Investments Name Awards Close in Time to MNPI Disclosures, Individual Name Construction in progress Construction in Progress [Member] Number of shares forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Entity Filer Category Entity Filer Category Shares issued to institutional investors (in shares) Shares, Issued Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Company Selected Measure Name Company Selected Measure Name Private Placement Private Placement [Member]