XML 45 R24.htm IDEA: XBRL DOCUMENT
v3.20.1

Organization and Significant Accounting Policies - Additional Information (Detail) |  |  | 1 Months Ended | 6 Months Ended |
--- | --- | --- | --- | --- | ---
Oct. 03, 2018 USD ($) Target | Sep. 28, 2016 USD ($) | Dec. 31, 2019 USD ($) | Mar. 31, 2020 USD ($) | Mar. 31, 2019 USD ($) | Sep. 30, 2019 USD ($)
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Proceeds from the issuance of common stock |  |  | $ 250,500,000 | $ 250,478,974 | $ 60,521,729 |
Cash and cash equivalents |  |  |  | 256,650,727 |  | $ 221,804,128
Restricted Cash |  |  |  | 1,800,000 |  |
Short term investments |  |  |  | 50,959,058 |  | 36,899,894
Long term investments |  |  |  | 190,618,075 |  | $ 44,175,993
Net increase (decrease) in cash and investments |  |  |  | 195,400,000 |  |
Right-of-use assets |  |  |  | 10,263,197 |  |
Right-of-use liabilities |  |  |  | 14,867,189 |  |
Janssen | JNJ-3989 (ARO-HBV) Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Milestone payment | $ 25,000,000 |  |  | 25,000,000 |  |
Janssen | Collaboration Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Number of additional targets for development and sales milestone payments | Target | 3 |  |  |  |  |
Janssen and JJDC | Collaboration and License agreements |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Cash received as due under agreement | $ 175,000,000 |  |  |  |  |
JJDC | Common Stock Purchase Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Proceeds from the issuance of common stock | 75,000,000 |  |  |  |  |
Amgen | License Collaboration and Stock Purchase Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Cash received as due under agreement |  | $ 35,000,000 |  |  |  |
Proceeds from the issuance of common stock |  | 21,500,000 |  |  |  |
Amgen | AMG-890 (ARO-LPA) Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Milestone payment |  | $ 10,000,000 |  |  |  |
Maximum | Janssen | License Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Development regulatory and sales milestones payments | 1,600,000,000 |  |  |  |  |
Maximum | Janssen | Collaboration Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Development regulatory and sales milestones payments | $ 1,900,000,000 |  |  |  |  |
Maximum | Amgen | AMG-890 (ARO-LPA) Agreement |  |  |  |  |  |
Organization And Significant Accounting Policies [Line Items] |  |  |  |  |  |
Development regulatory and sales milestones payments |  |  |  | $ 420,000,000 |  |

X
- Definition Cash received as due under agreement. + References No definition available. + Details
Name: | arwr_CashReceivedAsDueUnderAgreement
Namespace Prefix: | arwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Development regulatory and sales milestones payments. + References No definition available. + Details
Name: | arwr_DevelopmentRegulatoryAndSalesMilestonesPayments
Namespace Prefix: | arwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Increase decrease in cash and investments. + References No definition available. + Details
Name: | arwr_IncreaseDecreaseInCashAndInvestments
Namespace Prefix: | arwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Milestone payment earned. + References No definition available. + Details
Name: | arwr_MilestonePaymentEarned
Namespace Prefix: | arwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Milestone payment received. + References No definition available. + Details
Name: | arwr_MilestonePaymentReceived
Namespace Prefix: | arwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of additional targets for development and sales milestone payments. + References No definition available. + Details
Name: | arwr_NumberOfAdditionalTargetsForDevelopmentAndSalesMilestonePayments
Namespace Prefix: | arwr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Organization and significant accounting policies. + References No definition available. + Details
Name: | arwr_OrganizationAndSignificantAccountingPoliciesLineItems
Namespace Prefix: | arwr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3044-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CashAndCashEquivalentsAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity), classified as current. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26626-111562 + Details
Name: | us-gaap_HeldToMaturitySecuritiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity), classified as noncurrent. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26626-111562 + Details
Name: | us-gaap_HeldToMaturitySecuritiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Present value of lessee's discounted obligation for lease payments from operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
Name: | us-gaap_OperatingLeaseLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of lessee's right to use underlying asset under operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
Name: | us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3044-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586 + Details
Name: | us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=arwr_JanssenPharmaceuticalsIncorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=arwr_JNJ3989AROHBVAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=arwr_CollaborationAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=arwr_JanssenPharmaceuticalsAndJohnsonAndJohnsonInnovationJJDCIncorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=arwr_CollaborationAndLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=arwr_JohnsonAndJohnsonInnovationJJDCIncorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=arwr_CommonStockPurchaseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=arwr_AmgenIncorporatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=arwr_LicenseCollaborationAndStockPurchaseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=arwr_AMG890AROLPAAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=arwr_LicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |