Loss Per Share of Common Stock (EPS) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net loss	$ (12,682,982)	$ (5,334,067)
Less: income from change in fair value of warrant liability	(32,623)	(285,021)
Numerator for diluted net loss per common share	$ (12,715,605)	$ (5,619,088)
Basic weighted average common shares outstanding (in shares)	22,814,142	22,249,474
Dilutive common shares from assumed warrant exercises (in shares)	43,872	71,999
Diluted weighted average shares of common stock outstanding (in shares)	22,858,014	22,321,473
Diluted net loss per share of common stock (in dollars per share)	$ (0.56)	$ (0.25)