Stockholders' Equity - Schedule of Stockholders' Equity Note, Warrants or Rights (Detail) (USD $)				12 Months Ended
	Dec. 31, 2013	Oct. 31, 2012 Warrant [Member]	Jun. 30, 2011 Warrant [Member]	Dec. 31, 2013 Warrant [Member] Rusnano [Member]	Dec. 31, 2012 Warrant [Member] Rusnano [Member]
Class of Warrant or Right [Line Items]
Number of Warrants Outstanding, Beginning balance	10,534,245			10,377,995	10,121,219
Number of Warrants, Granted				156,250	4,312,500
Number of Warrants, Forfeited, Canceled					(4,055,724)
Number of Warrants Outstanding, Ending balance	10,534,245			10,534,245	10,377,995
Weighted Average Exercise Price, Outstanding, Beginning balance				2.94	3.76
Weighted Average Exercise Price, Granted				$ 1.60	$ 3.00
Weighted Average Exercise Price, Forfeited, Canceled					$ 5.07
Weighted Average Exercise Price, Outstanding, Ending balance				2.70	2.94
Number of Common Shares Exercisable Into Outstanding, Beginning balance		562,500	2,936,250	10,377,995	12,564,193
Number of Common Shares Exercisable Into, Granted				156,250	4,312,500
Number of Common Shares Exercisable Into, Forfeited, Canceled					(6,498,698)
Number of Common Shares Exercisable Into Outstanding, Ending balance		562,500	2,936,250	10,534,245	10,377,995