XML 55 R36.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions |  |  | 1 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Nov. 18, 2016 | Sep. 28, 2016 | Nov. 30, 2016 | Sep. 30, 2017 | Mar. 21, 2017 | Sep. 30, 2016
Class Of Stock [Line Items] |  |  |  |  |  |
Capital stock authorized for issuance |  |  |  | 150,000,000 |  |
Common stock, shares authorized |  |  |  | 145,000,000 |  | 145,000,000
Common stock, par value |  |  |  | $ 0.001 |  | $ 0.001
Preferred stock, shares authorized |  |  |  | 5,000,000 |  | 5,000,000
Preferred stock, par value |  |  |  | $ 0.001 |  | $ 0.001
Common stock, shares outstanding |  |  |  | 74,785,426 |  | 69,746,685
Preferred stock, shares outstanding |  |  |  | 0 |  | 15,652
Dividend distribution, declared date |  |  |  | Mar. 21, 2017 |  |
Number of rights distributed for each outstanding share of common stock |  |  |  |  | 1 |
Dividend distribution, record date |  |  |  | Mar. 22, 2017 |  |
Rights expiration date |  |  |  | Mar. 21, 2018 |  |
Common Stock Purchase Agreement | Amgen | First Tranche |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |
Common stock shares sold |  | 1,256,983 |  |  |  |
Common stock shares sold, price per share |  | $ 7.16 |  |  |  |
Net proceeds received |  | $ 9.0 |  |  |  |
Common Stock Purchase Agreement | Amgen | Second Tranche |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |
Common stock shares sold | 1,745,810 |  |  |  |  |
Common stock shares sold, price per share | $ 7.16 |  |  |  |  |
Net proceeds received |  |  | $ 12.5 |  |  |
Series C Preferred Stock |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |
Preferred stock, shares converted |  |  |  | 15,652 |  |
Common stock, issued upon conversion of preferred stock |  |  |  | 2,670,989 |  |
Preferred stock, shares outstanding |  |  |  | 0 |  |
Series D Junior Participating Preferred |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |
Preferred stock, par value |  |  |  |  | $ 0.001 |
Preferred stock conversion of purchase price per one one thousandth of share |  |  |  |  | $ 20 |
Beneficial ownership percentage of common stock upon right exercisable |  |  |  |  | 15.00% |
Number of rights distributed for each outstanding share of common stock |  |  |  | 1 |  |
2004 Equity Incentive Plan, 2013 Equity Incentive Plan, and Inducement Grants |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |
Common Stock, Share reserve for issuance |  |  |  | 8,902,416 |  |

X
- Definition Class of warrant or right number of rights distribution for each outstanding share common stock. + References No definition available. + Details
Name: | arwr_ClassOfWarrantOrRightNumberOfRightsDistributionForEachOutstandingShareCommonStock
Namespace Prefix: | arwr_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of rights distributed for each outstanding share of common stock + References No definition available. + Details
Name: | arwr_NumberOfRightsDistributedForEachOutstandingShareOfCommonStock
Namespace Prefix: | arwr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Preferred stock conversion of purchase price per one one thousandth of share. + References No definition available. + Details
Name: | arwr_PreferredStockConversionOfPurchasePricePerOneOneThousandthOfShare
Namespace Prefix: | arwr_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Preferred stock rights exercisable beneficial ownership percentage of common stock. + References No definition available. + Details
Name: | arwr_PreferredStockRightsExercisableBeneficialOwnershipPercentageOfCommonStock
Namespace Prefix: | arwr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Rights expiration date. + References No definition available. + Details
Name: | arwr_RightsExpirationDate
Namespace Prefix: | arwr_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of authorized capital units or capital shares. This element is relevant to issuers of face-amount certificates and registered investment companies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04.16(a)) -URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e603758-122996 + Details
Name: | us-gaap_CapitalUnitsAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of common stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644 + Details
Name: | us-gaap_CommonStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of shares converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586 + Details
Name: | us-gaap_ConversionOfStockSharesConverted1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares issued for each share of convertible preferred stock that is converted. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644 + Details
Name: | us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Date the dividend to be paid was declared, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 + Details
Name: | us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Cash received on stock transaction after deduction of issuance costs. + References No definition available. + Details
Name: | us-gaap_SaleOfStockConsiderationReceivedOnTransaction
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 Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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_VestingAxis=arwr_FirstTrancheMember
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_StatementClassOfStockAxis=us-gaap_SeriesCPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_SeriesDPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=arwr_TwoThousandFourEquityIncentivePlanTwoThousandThirteenEquityIncentivePlanAndInducementGrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |