Consolidated Statements of Cash Flows (USD $)	3 Months Ended		116 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (4,780,727)	$ (2,686,799)	$ (158,433,732)
Net (income) loss attributable to nonconrolling interests	166,568	201,294	18,985,853
Net income (loss) attributable to Arrowhead	(4,614,159)	(2,485,505)	(139,447,879)
(Income) loss from discontinued operations	18	220	42,838,072
Realized and unrealized (gain) loss on investments		58,091	(762,954)
Charge for bad debt allowance			2,497,300
(Gain) loss from sale of subsidiary			(306,344)
(Gain) loss on purchase of Roche Madison		(1,576,107)	(1,576,107)
(Gain) Loss on disposal of fixed assets	(18,493)		1,187,972
Stock issued for professional services			741,632
Change in value of derivatives	(44,275)	66,904	(3,325,679)
Purchased in-process research and development			15,851,555
Stock-based compensation	395,675	251,878	13,977,143
Depreciation and amortization	449,597	454,444	7,858,883
Amortization (accretion) of note discounts, net	572	3,783	2,024
Gain on sale of stock in subsidiary			(2,292,800)
Non-cash impairment expense			1,642,775
Equity in income (loss) of unconsolidated affiliates	63,557	106,527	1,026,964
Noncontrolling interest	(166,568)	(201,294)	(18,985,853)
Changes in operating assets and liabilities:
Receivables	(105,891)	172,230	(5,851)
Other receivables		(419,238)	(2,543,142)
Prepaid expenses	157,208	(30,070)	(323,891)
Other current assets	(12,441)	(1)	(115,654)
Deposits			(60,542)
Accounts payable	(68,459)	137,448	429,851
Accrued expenses	111,865	408,783	832,774
Other liabilities	14,208	346,551	1,144,369
NET CASH USED IN OPERATING ACTIVITIES OF CONTINUING OPERATIONS	(3,837,586)	(2,705,356)	(79,715,382)
CASH FLOWS FROM INVESTING ACTIVITIES OF CONTINUING OPERATIONS:
Purchase of property and equipment	(9,439)	(69,424)	(4,054,748)
Proceeds from sale of investments		509,009	3,313,609
Proceeds from sale of fixed assets	121,418		554,105
Cash transferred in acquisitions/divestitures		100,035	(1,579,365)
Purchase of marketable securities-US Treasury Bills			(18,575,915)
Purchase of MASA Energy, LLC			(250,000)
Minority equity investment			(2,000,000)
Cash paid for interest in Insert			(10,150,000)
Cash obtained from interest in Insert			10,529,594
Proceeds from sale of marketable securities-US Treasury Bills			18,888,265
Proceeds from sale of subsidiaries			359,375
Payment for patents			(303,440)
Restricted cash			50,773
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES OF CONTINUING OPERATIONS	111,979	539,620	(3,217,747)
CASH FLOWS FROM FINANCING ACTIVITIES OF CONTINUING OPERATIONS:
Principal payments on capital leases	(53,098)	(39,940)	(249,704)
Proceeds from issuance of Calando debt			2,516,467
Proceeds from sale of stock in subsidiary		8,000	20,902,100
Proceeds from issuance of common stock and warrants, net	3,332,467	1,463,833	109,585,478
NET CASH PROVIDED BY FINANCING ACTIVITIES OF CONTINUING OPERATIONS	3,279,369	1,431,893	132,754,341
Cash flows from discontinued operations:
Operating cash flows	(18)	(420)	(46,003,805)
Investing cash flows			790,625
Financing cash flows			(1,677,000)
Net cash provided by (used in) discontinued operations:	(18)	(420)	(46,890,180)
NET INCREASE (DECREASE) IN CASH	(446,256)	(734,263)	2,931,032
CASH AT BEGINNING OF PERIOD	3,377,288	7,507,389
CASH AT END OF PERIOD	2,931,032	6,773,126	2,931,032
Supplementary disclosures:
Interest paid	11,114	10,300	291,802
Taxes paid			$ 742,500