Warrant Liability - Summary of Warrant Liability (Detail) (USD $)	Dec. 31, 2013	Oct. 31, 2013
Class of Warrant or Right [Line Items]
Number Outstanding	9,551,378
Exercise Price per share		1.80
Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Number Outstanding	8,116,895
Exercise Price per share	1.40
November 2008 Financing [Member]
Class of Warrant or Right [Line Items]
Number Outstanding	1,034,483
Exercise Price per share	23.00
November 2009 Financing [Member]
Class of Warrant or Right [Line Items]
Number Outstanding	400,000
Exercise Price per share	15.00
Outstanding warrants [Member]
Class of Warrant or Right [Line Items]
Fair Value	$ 5,541,809
Outstanding warrants [Member] \| Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Fair Value	5,541,809
Outstanding warrants [Member] \| November 2008 Financing [Member]
Class of Warrant or Right [Line Items]
Fair Value
Outstanding warrants [Member] \| November 2009 Financing [Member]
Class of Warrant or Right [Line Items]
Fair Value