Consolidated Statements of Operations (USD $)	12 Months Ended		113 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012
REVENUE	$ 146,875	$ 296,139	$ 4,138,834
OPERATING EXPENSES
Salaries and payroll-related costs	6,414,921	1,408,366	26,392,130
General and administrative expenses	6,439,323	3,795,380	31,353,215
Research and development	5,391,463	3,277,760	42,618,748
Stock-based compensation	1,241,404	1,376,921	13,581,468
Depreciation and amortization	1,748,975	267,978	7,409,286
TOTAL OPERATING EXPENSES	21,236,086	10,126,405	121,354,847
OPERATING LOSS	(21,089,211)	(9,830,266)	(117,216,013)
OTHER INCOME (EXPENSE)
Equity in income (loss) of unconsolidated affiliates	(240,154)	(163,180)	(963,407)
Impairment of investment in unconsolidated affiliates	(1,642,775)		(1,642,775)
Gain on purchase of Roche Madison	1,576,107		1,576,107
Loss on sale of property and equipment, net	(1,079,377)		(1,206,465)
Realized and unrealized gain (loss) on marketable securities	(58,091)	(261,219)	62,954
Interest income (expense), net	35,966	86,530	2,750,444
Change in value of derivatives	386,892	1,133,127	3,281,404
Gain on sale of stock in subsidiary			2,292,800
Other income		250,000	250,000
TOTAL OTHER INCOME (EXPENSE)	(1,021,432)	1,045,258	6,401,062
LOSS FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(22,110,643)	(8,785,008)	(110,814,951)
Provision for income taxes
LOSS FROM CONTINUING OPERATIONS	(22,110,643)	(8,785,008)	(110,814,951)
Income (loss) from discontinued operations	(80)	1,373,396	(47,546,642)
Gain on disposal of discontinued operations		3,919,213	4,708,588
NET INCOME (LOSS) FROM DISCONTINUED OPERATIONS	(80)	5,292,609	(42,838,054)
NET LOSS	(22,110,723)	(3,492,399)	(153,653,005)
Net (income) loss attributable to noncontrolling interests	984,795	363,514	18,819,285
NET LOSS ATTRIBUTABLE TO ARROWHEAD	$ (21,125,928)	$ (3,128,885)	$ (134,833,720)
Earnings per share-basic and diluted:
Loss from continuing operations attributable to Arrowhead common shareholders	$ (1.90)	$ (1.18)
Loss from discontinued operations attributable to Arrowhead common shareholders		$ 0.74
Net loss attributable to Arrowhead shareholders	$ (1.90)	$ (0.44)
Weighted average shares outstanding	11,129,766	7,181,121