Annual report pursuant to Section 13 and 15(d)

Warrants (Narrative) (Details)

v3.8.0.1
Warrants (Narrative) (Details) - $ / shares
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Class of Warrant or Right [Line Items]      
Number of warrants, Outstanding 7,099,609 5,452,691 2,649,199
Exercise price $ 4.55 $ 4.92 $ 7.97
Warrant expiration date, start Jul. 26, 2018    
Warrant expiration date, end Apr. 17, 2023    
Average remaining contractual life of warrants outstanding 4 years    
Probability of entering into a fundamental transaction 5.00%    
Maximum [Member]      
Class of Warrant or Right [Line Items]      
Exercise price $ 12.80    
Minimum [Member]      
Class of Warrant or Right [Line Items]      
Exercise price $ 2.85