Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended
	Mar. 31, 2014	Jun. 30, 2014
2010 Warrants [Member]
Class of Stock [Line Items]
Weighted average term	10 months 24 days	8 months 12 days
Warrant exercise price probability	5.00%	5.00%
Percentage of volatility		187.70%
Risk free interest rate	0.13%	0.09%
2010 Warrants [Member] | Minimum [Member]
Class of Stock [Line Items]
Percentage of volatility	66.50%
2010 Warrants [Member] | Maximum [Member]
Class of Stock [Line Items]
Percentage of volatility	129.70%
2011 Warrants [Member]
Class of Stock [Line Items]
Weighted average term	1 year 9 months 18 days	1 year 6 months
Warrant exercise price probability	5.00%	5.00%
Percentage of volatility	101.80%	132.70%
Risk free interest rate	0.29%	0.29%
2013 Warrants [Member]
Class of Stock [Line Items]
Weighted average term	3 years 10 months 24 days
Warrant exercise price probability	5.00%
Percentage of volatility	84.70%
Warrant Liability		0
2013 Warrants [Member] | Minimum [Member]
Class of Stock [Line Items]
Risk free interest rate	0.77%
2013 Warrants [Member] | Maximum [Member]
Class of Stock [Line Items]
Risk free interest rate	1.32%