Warrant Liability - Summary of Warrant Liability (Detail) (USD $)	Mar. 31, 2014
Class of Warrant or Right [Line Items]
Number Outstanding	9,551,378
Outstanding warrants [Member]
Class of Warrant or Right [Line Items]
Fair Value	$ 5,868,000
Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Number Outstanding	8,116,895
Exercise Price per share	1.40
Series A Warrants [Member] | Outstanding warrants [Member]
Class of Warrant or Right [Line Items]
Fair Value	5,868,433
November 2008 Financing [Member]
Class of Warrant or Right [Line Items]
Number Outstanding	1,034,483
Exercise Price per share	23.00
November 2008 Financing [Member] | Outstanding warrants [Member]
Class of Warrant or Right [Line Items]
Fair Value
November 2009 Financing [Member]
Class of Warrant or Right [Line Items]
Number Outstanding	400,000
Exercise Price per share	15.00
November 2009 Financing [Member] | Outstanding warrants [Member]
Class of Warrant or Right [Line Items]
Fair Value