Share-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Outstanding, beginning balance (shares)	403,986	286,568
Granted (shares)	2,550,000	195,332
Exercised (shares)		(77,914)
Forfeited and Expired (shares)	(376,126)
Outstanding, ending balance (shares)	2,577,860	403,986
Exercisable at December 31, 2017, Number of shares (shares)	217,066
Weighted Average Exercise Price (usd per share)
Outstanding, beginning balance (in usd per share)	$ 4.62	$ 6.46
Granted (in usd per share)	0.65	1.86
Options exercised in period (in usd per share)		4.46
Forfeited and Expired (in usd per share)	1.35
Outstanding, ending balance (in usd per share)	1.17	$ 4.62
Exercisable at December 31, 2017, Weighted average exercised price per share (in usd per share)	$ 6.04
Options outstanding, weighted average remaining contractual term (years)	8 years 8 months 12 days	8 years 1 month 6 days
Options exercisable, weighted average remaining contractual term (years)	6 years 4 months 24 days
Outstanding at December 31, 2017, Aggregate intrinsic value	$ 0	$ 0
Exercisable at December 31, 2017, Aggregate intrinsic value	$ 0