Consolidated Statements of Operations (USD $)	3 Months Ended		6 Months Ended		131 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014
Statement Consolidated Statements Of Operations [Line Items]
REVENUE	$ 43,750	$ 43,750	$ 87,500	$ 202,766	$ 4,516,600
OPERATING EXPENSES
Salaries and payroll-related costs	3,097,902	1,725,176	5,179,693	3,354,599	38,239,492
General and administrative expenses	1,347,677	779,970	2,261,461	1,697,646	37,103,540
Research and development	5,216,446	2,125,019	8,349,460	3,701,685	59,673,835
Stock-based compensation	1,198,444	355,108	1,719,582	750,782	16,837,321
Depreciation and amortization	395,779	448,765	799,184	898,362	9,959,882
Impairment expense					1,308,047
Contingent consideration - fair value adjustments					1,421,652
TOTAL OPERATING EXPENSES	11,256,248	5,434,038	18,309,380	10,403,074	164,543,769
OPERATING LOSS	(11,212,498)	(5,390,288)	(18,221,880)	(10,200,308)	(160,027,169)
OTHER INCOME (EXPENSE)
Equity in income (loss) of unconsolidated affiliates	(9,597)	(157,612)	(148,053)	(221,169)	(1,752,601)
Impairment of investment in unconsolidated affiliates					(1,642,775)
Gain on purchase of Roche Madison					1,576,107
Gain (loss) on sale of fixed assets, net	(5,316)	(54,932)	(58,878)	(36,440)	(1,341,731)
Realized and unrealized gain (loss) in marketable securities					62,954
Interest income (expense), net	119,390	(27,567)	159,968	(20,151)	2,812,502
Change in value of derivatives	(2,951,225)	(29,403)	(6,470,803)	14,873	(8,489,788)
Gain on sale of stock in subsidiary					2,292,800
Other income (expense)	76,546	(1,279,881)	71,215	(1,257,196)	(676,760)
TOTAL OTHER INCOME (EXPENSE)	(2,770,202)	(1,549,395)	(6,446,551)	(1,520,083)	(7,159,292)
LOSS FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(13,982,700)	(6,939,683)	(24,668,431)	(11,720,391)	(167,186,461)
Provision for income taxes
LOSS FROM CONTINUING OPERATIONS	(13,982,700)	(6,939,683)	(24,668,431)	(11,720,391)	(167,186,461)
Income (loss) from discontinued operations		(336)		(354)	(47,546,996)
Gain on disposal of discontinued operations					4,708,588
NET INCOME (LOSS) FROM DISCONTINUED OPERATIONS		(336)		(354)	(42,838,408)
NET LOSS	(13,982,700)	(6,940,019)	(24,668,431)	(11,720,745)	(210,024,869)
Net loss attributable to noncontrolling interests	40,179	182,082	97,600	348,650	19,477,029
NET LOSS ATTRIBUTABLE TO ARROWHEAD	$ (13,942,521)	$ (6,757,937)	$ (24,570,831)	$ (11,372,095)	$ (190,547,840)
NET LOSS PER SHARE ATTRIBUTABLE TO ARROWHEAD SHAREHOLDERS - BASIC & DILUTED:	$ (0.31)	$ (0.41)	$ (0.60)	$ (0.74)
Weighted average shares outstanding - basic and diluted	44,321,847	16,461,693	40,941,903	15,272,703