Operating Matters and Liquidity - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 23, 2014	May 17, 2013
Line of Credit Facility [Line Items]
Net Income Loss	$ (1,843,195)	$ (1,664,519)	$ 6,300,000	$ 7,100,000
Accumulated deficit	(122,933,507)		(121,090,312)
Class of Warrant or Right, Exercise Price of Warrants or Rights						$ 0.2745
Class of Warrant or Right, Number of Securities Called by Warrants or Rights						32,786,885
Venture Loan [Member]
Line of Credit Facility [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 0.1003
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					2,492,523
Debt Instrument, Description of Variable Rate Basis					The loan bears interest at a floating rate equal to the One Month LIBOR Rate (with a floor of 0.50%) plus 8.50%. In the event that the One Month LIBOR Rate, as reported in the Wall Street Journal, exceeds 0.50%, the interest rate will be adjusted by an amount equal to the difference between such rates at the end of that particular month
Debt Instrument, Payment Terms					The loan is to be repaid in forty-five (45) monthly payments consisting of fifteen (15) monthly payments of only interest followed by thirty (30) equal monthly payments of principal and interest. In addition, at the end of the repayment term (or at early termination of the loan) a final payment equal to 4.5% of the loan will be due and payable
Proceeds from Issuance of Long-term Debt					5,000,000
Debt Instrument, Interest Rate, Stated Percentage	9.00%				9.00%
Warrants Expire Term					10 years
December 2014 Private Placement [Member]
Line of Credit Facility [Line Items]
Sale of Stock, Number of Shares Issued in Transaction					50,099,700
Sale of Stock, Price Per Share					$ 0.1003
Sale of Stock, Consideration Received on Transaction					5,025,000
2013 Warrants [Member]
Line of Credit Facility [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights						$ 0.2745
Class of Warrant or Right, Number of Securities Called by Warrants or Rights						32,786,885
Warrants Expire Term						7 years
Private Placement [Member]
Line of Credit Facility [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.1003
2014 warrants [Member]
Line of Credit Facility [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 0.1003
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					50,099,700
Warrants Expire Term					7 years
Common Stock [Member]
Line of Credit Facility [Line Items]
Net Income Loss	0
Common Stock [Member] | May 2013 Private Placement [Member]
Line of Credit Facility [Line Items]
Sale of Stock, Number of Shares Issued in Transaction						43,715,847
Sale of Stock, Price Per Share						$ 0.2745
Sale of Stock, Consideration Received on Transaction						$ 12,000,000