Stockholder's Equity - RSA Activity (Details) - Unvested restricted stock awards	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Number of RSAs
Granted (in shares)	449,500
2012 Omnibus Incentive Plan
Number of RSAs
Outstanding (in shares)	2,292,308
Granted (in shares)	449,500
Exercised (in shares)	(60,000)
Forfeited or expired (in shares)	(94,900)
Outstanding (in shares)	2,586,908
Weighted-Average Stock Price
Outstanding, Weighted-Average Stock Price (in dollars per share) | $ / shares	$ 3.77
Granted, Weighted-Average Stock Price (in dollars per share) | $ / shares	2.17
Exercised, Weighted-Average Stock Price (in dollars per share) | $ / shares	4.87
Forfeited or expired, Weighted-Average Stock Price (in dollars per share) | $ / shares	3.71
Outstanding, Weighted-Average Stock Price (in dollars per share) | $ / shares	$ 3.47
The 2016 Inducement Omnibus Incentive Plan
Number of RSAs
Outstanding (in shares)	1,242,250
Granted (in shares)	0
Exercised (in shares)	(166,498)
Forfeited or expired (in shares)	(259,043)
Outstanding (in shares)	816,709
Weighted-Average Stock Price
Outstanding, Weighted-Average Stock Price (in dollars per share) | $ / shares	$ 4.62
Granted, Weighted-Average Stock Price (in dollars per share) | $ / shares	0.00
Exercised, Weighted-Average Stock Price (in dollars per share) | $ / shares	5.19
Forfeited or expired, Weighted-Average Stock Price (in dollars per share) | $ / shares	5.34
Outstanding, Weighted-Average Stock Price (in dollars per share) | $ / shares	$ 4.28