XML 55 R34.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Property and Equipment - Additional Information (Detail) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2016 USD ($)
Research Facility in Madison |
Property, Plant and Equipment [Line Items] |
Impairment expense related to leasehold improvements | $ 1.1

X
- Definition The adjustment to reduce the value of existing agreements that specify the lessee's rights to use the leased property. This expense is charged when the estimates of future profits generated by the leased property are reduced. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228 + Details
Name: | us-gaap_ImpairmentOfLeasehold
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis=arwr_ResearchFacilityInMadisonMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |