XML 64 R47.htm IDEA: XBRL DOCUMENT
v3.25.1

Investments - Schedule of Short-term, Long-term Investments and Marketable Securities (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Sep. 30, 2024
--- | --- | ---
Schedule Of Held To Maturity Securities And Marketable Securities [Line Items] |  |
Current investments, Adjusted Basis | $ 910,744 | $ 577,465
Current investments, Gross Unrealized Gains | 1,063 | 837
Current investments, Gross Unrealized Losses | (107) | (26)
Current investments, Fair Value | 911,700 | 578,276
Available-for-sale securities |  |
Schedule Of Held To Maturity Securities And Marketable Securities [Line Items] |  |
Current investments, Adjusted Basis | 910,744 | 577,465
Current investments, Gross Unrealized Gains | 1,063 | 837
Current investments, Gross Unrealized Losses | (107) | (26)
Current investments, Fair Value | $ 911,700 | $ 578,276

X
- Definition Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, Current + References No definition available. + Details
Name: | arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainCurrent
Namespace Prefix: | arwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, Current + References No definition available. + Details
Name: | arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossCurrent
Namespace Prefix: | arwr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Schedule of held to maturity securities and marketable securities. + References No definition available. + Details
Name: | arwr_ScheduleOfHeldToMaturitySecuritiesAndMarketableSecuritiesLineItems
Namespace Prefix: | arwr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481830/320-10-45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |