Consolidated Balance Sheets - USD ($)	Jun. 30, 2020	Sep. 30, 2019
CURRENT ASSETS
Cash and cash equivalents	$ 219,322,617	$ 221,804,128
Accounts receivable	21,692,564	661,361
Prepaid expenses	4,096,473	3,317,999
Other current assets	2,411,937	2,563,435
Short term investments	67,709,263	36,899,894
TOTAL CURRENT ASSETS	315,232,854	265,246,817
Property and equipment, net	30,389,707	23,214,899
Intangible assets, net	15,788,258	17,063,580
Long term investments	177,529,881	44,175,993
Right-of-use assets	16,522,013
Other assets	265,359	144,148
TOTAL ASSETS	555,728,072	349,845,437
CURRENT LIABILITIES
Accounts payable	4,073,869	7,649,921
Accrued expenses	9,414,696	6,504,729
Accrued payroll and benefits	1,991,001	4,955,887
Lease liabilities	1,011,951
Deferred rent		173,952
Deferred revenue	26,274,362	77,769,629
Other current liabilities	17,262	16,561
TOTAL CURRENT LIABILITIES	42,783,141	97,070,679
LONG-TERM LIABILITIES
Lease liabilities, net of current portion	20,359,726
Deferred rent, net of current portion		3,703,364
Deferred revenue, net of current portion		5,035,142
TOTAL LONG-TERM LIABILITIES	20,359,726	8,738,506
Commitments and contingencies (Note 7)
Arrowhead Pharmaceuticals, Inc. stockholders' equity:
Common stock, $0.001 par value; 145,000,000 shares authorized; 102,250,872 and 95,506,271 shares issued and outstanding as of June 30, 2020 and September 30, 2019, respectively	194,620	187,876
Additional paid-in capital	948,532,470	664,086,155
Accumulated other comprehensive income (loss)	(175,219)	(391,624)
Accumulated deficit	(455,411,478)	(419,290,967)
Total Arrowhead Pharmaceuticals, Inc. stockholders' equity	493,140,393	244,591,440
Noncontrolling interest	(555,188)	(555,188)
TOTAL STOCKHOLDERS’ EQUITY	492,585,205	244,036,252
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 555,728,072	$ 349,845,437