XML 79 R58.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Subsequent Events - Additional Information (Detail) - USD ($) |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Nov. 18, 2016 | Nov. 30, 2016 | Aug. 31, 2016 | Sep. 30, 2016 | Sep. 30, 2014 | Nov. 29, 2016
Subsequent Event [Line Items] |  |  |  |  |  |
Proceeds from the issuance of common stock |  |  | $ 43,200,000 | $ 52,231,433 | $ 172,641,671 |
Subsequent Event |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Percentage of workforce reduced due to discontinued clinical program |  |  |  |  |  | 30.00%
Common Stock Purchase Agreement | Amgen |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Proceeds from the issuance of common stock |  |  |  | $ 9,000,000 |  |
Common Stock Purchase Agreement | Amgen | Subsequent Event |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Proceeds from the issuance of common stock | $ 12,500,000 |  |  |  |  |
Second Tranche | Common Stock Purchase Agreement | Amgen | Subsequent Event |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Common stock issued | 1,745,810 |  |  |  |  |
Second Collaboration and License Agreement | Amgen | Subsequent Event |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Cash received as due under collaboration agreement | $ 30,000,000 | $ 30,000,000 |  |  |  |

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

X
- Definition Percentage of reduction in workforce. + References No definition available. + Details
Name: | arwr_PercentageOfReductionInWorkforce
Namespace Prefix: | arwr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of shares issued or sold by the subsidiary or equity method investee per stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
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_AmgenIncorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=arwr_SecondTrancheMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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