Warrants - Summary of Warrant Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Increase (Decrease) in Warrants Outstanding [Roll Forward]
Number of warrants outstanding (shares), beginning balance	6,998,843
Number of warrants granted during the period (shares)	23,842,856
Number of warrants adjusted during the period (shares)	80,197	154,288
Number of warrants exercised during the period (shares)	(3,531,104)
Number of warrants expired during the period (share)	(126,627)
Number of warrants outstanding (shares), ending balance	27,264,165	6,998,843
Warrants exercise price (usd per share), beginning balance	$ 5.98
Weighted-average exercise price, warrants granted during the period (usd per share)	0.84
Weighted-average exercise price, warrants adjusted during the period (usd per share)	0.77
Weighted-average exercise price, warrants exercised during the period (usd per share)	0.02
Weighted-average exercise price, warrants expired during the period (usd per share)	0.77
Warrants exercise price (usd per share), ending balance	$ 2.26	$ 5.98
Warrants
Increase (Decrease) in Warrants Outstanding [Roll Forward]
Number of warrants outstanding (shares), beginning balance	6,998,843
Number of warrants granted during the period (shares)	0
Number of warrants adjusted during the period (shares)	80,197
Number of warrants exercised during the period (shares)	(25,000)
Number of warrants expired during the period (share)	(126,627)
Number of warrants outstanding (shares), ending balance	6,927,413	6,998,843
Warrants
Increase (Decrease) in Warrants Outstanding [Roll Forward]
Number of warrants outstanding (shares), beginning balance	0
Number of warrants granted during the period (shares)	23,842,856
Number of warrants exercised during the period (shares)	(3,506,104)
Number of warrants expired during the period (share)	0
Number of warrants outstanding (shares), ending balance	20,336,752	0