Consolidated Statements of Operations (unaudited) (USD $)	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
REVENUE	$ 170,750	$ 43,750
OPERATING EXPENSES
Research and development	17,744,312	3,133,014
Salaries and payroll-related costs	3,150,617	2,081,791
General and administrative expenses	2,086,202	913,784
Stock-based compensation	2,014,856	521,138
Depreciation and amortization	290,039	403,405
TOTAL OPERATING EXPENSES	25,286,026	7,053,132
OPERATING LOSS	(25,115,276)	(7,009,382)
OTHER INCOME (EXPENSE)
Equity in income (loss) of unconsolidated affiliates		(138,456)
Gain (loss) on sale of fixed assets, net	(26,381)	(53,562)
Interest income (expense), net	237,417	40,578
Change in value of derivatives	2,382,142	(3,519,579)
Other income (expense)	(53,184)	(5,331)
TOTAL OTHER INCOME (EXPENSE)	2,539,994	(3,676,350)
LOSS BEFORE INCOME TAXES	(22,575,282)	(10,685,732)
NET LOSS	(22,575,282)	(10,685,732)
Net loss attributable to noncontrolling interests		57,420
NET LOSS ATTRIBUTABLE TO ARROWHEAD	$ (22,575,282)	$ (10,628,312)
NET LOSS PER SHARE ATTRIBUTABLE TO ARROWHEAD SHAREHOLDERS - BASIC AND DILUTED:	$ (0.41)	$ (0.28)
Weighted average shares outstanding - basic and diluted	54,692,392	37,741,743