Warrant Activity (Detail) (Warrant, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Warrant
Number of Shares Issuable
Balance, Beginning	41,595,655	27,353,151
Granted	7,435,901	14,875,004
Cancelled pursuant to Tender Offer	(46,276,774)
Exercised	(155,568)
Cancelled	(1,433,068)	(632,500)
Balance, Ending	1,166,146	41,595,655
Weighted Average Exercise Price
Balance, Beginning	$ 0.69	$ 0.79
Granted	$ 0.67	$ 0.60
Cancelled pursuant to Tender Offer	$ 0.67
Exercised	$ 0.60
Cancelled	$ 0.87	$ 1.56
Balance, Ending	$ 1.13	$ 0.69