Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2026	Sep. 30, 2025
Current assets:
Cash, cash equivalents and restricted cash	$ 54,759	$ 226,548
Accounts receivable	8,556	6,824
Available-for-sale securities, at fair value	1,547,201	692,818
Prepaid expenses	25,373	10,933
Other current assets	35,522	13,516
Total current assets	1,671,411	950,639
Property, plant and equipment, net	373,301	382,515
Intangible assets, net	5,586	6,861
Right-of-use assets	55,667	43,891
Other assets	6,048	1,389
Total Assets	2,112,013	1,385,295
Current liabilities:
Accounts payable	27,776	17,674
Accrued expenses	86,174	90,419
Accrued payroll and benefits	23,455	26,895
Lease liabilities	5,322	7,289
Deferred revenue	94,596	2,399
Credit facility	40,000	40,000
Other liabilities	6,023	10,811
Total current liabilities	283,346	195,487
Long-term liabilities:
Lease liabilities, net of current portion	114,298	104,112
Deferred revenue, net of current portion	31,743	0
Liability related to the sale of future royalties	392,512	367,397
Credit facility, net of current portion	141,366	214,883
Convertible Notes, Net	682,707	0
Total long-term liabilities	1,362,626	686,392
Commitments and contingencies (Note 7)
Noncontrolling interest and stockholders’ equity:
Common stock, $0.001 par value: Authorized 290,000 shares; 143,796 shares issued and 141,135 outstanding as of June 30, 2026 and 138,363 shares issued and 135,702 outstanding as of September 30, 2025	237	231
Additional paid-in capital	2,443,074	2,139,725
Accumulated other comprehensive (loss) income	(1,234)	6,443
Accumulated deficit	(1,923,355)	(1,627,154)
Treasury stock; at cost; 2,661 shares of common stock at June 30, 2026 and September 30, 2025	(53,193)	(53,193)
Stockholders’ equity	465,529	466,052
Noncontrolling interest	512	37,364
Total noncontrolling interest and stockholders’ equity	466,041	503,416
Total Liabilities, Noncontrolling Interest and Stockholders’ Equity	2,112,013	1,385,295
Consolidated Entity Excluding Variable Interest Entities (VIE)
Current assets:
Cash, cash equivalents and restricted cash	19,685	88,706
Variable Interest Entity, Primary Beneficiary
Current assets:
Cash, cash equivalents and restricted cash	$ 35,074	$ 137,842

Royalties, Liability, Noncurrent

No definition available.

Name:	arwr_RoyaltiesLiabilityNoncurrent
Namespace Prefix:	arwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).