Warrant Liabilities (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
(Loss) Gain on warrant liabilities	$ (20,210,094)	$ 2,766,704	$ 7,915,027
Warrant [Member]
Derivative [Line Items]
Expected dividend yield (in hundredths)	0.00%	0.00%	0.00%
Warrants classified as liabilities	6,984,716	6,984,716	7,115,447
(Loss) Gain on warrant liabilities	$ (20,210,094)	$ 2,766,704	$ 7,915,027
Warrant [Member] | Minimum [Member]
Derivative [Line Items]
Risk-free interest rate (in hundredths)	0.13%	0.25%	0.36%
Expected lives	0 years 11 months 12 days	1 year 11 months 12 days	0 years 11 months 16 days
Expected volatility (in hundredths)	83.40%	72.60%	75.00%
Warrant [Member] | Maximum [Member]
Derivative [Line Items]
Risk-free interest rate (in hundredths)	0.58%	0.45%	0.83%
Expected lives	2 years 7 months 2 days	3 years 7 months 2 days	4 years 7 months 2 days
Expected volatility (in hundredths)	95.30%	76.00%	89.80%