Annual reports filed by certain Canadian issuers pursuant to Section 15(d) and Rule 15d-4

Derivative warrant liabilities - Summary of derivative warrant liabilities (Details)

v3.19.1
Derivative warrant liabilities - Summary of derivative warrant liabilities (Details) - USD ($)
shares in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Changes in derivative financial liabilities [Roll Forward]    
Beginning balance of derivative financial liabilities $ 11,793  
Ending balance of derivative financial liabilities 21,747 $ 11,793
Warrants    
Changes in derivative financial liabilities [Roll Forward]    
Beginning balance of derivative financial liabilities 11,793 9,138
Conversion to equity (common shares) upon exercise of warrants   (21,269)
Revaluation of derivative warrant liability upon exercise of warrants   (4,857)
Revaluation of derivative warrant liability 9,954 28,781
Ending balance of derivative financial liabilities $ 21,747 $ 11,793
Changes in warrants [Roll Forward]    
Beginning balance of warrants outstanding (in shares) 5,261 10,136
Conversion to equity (common shares) upon exercise of warrants (in shares)   (4,875)
Ending balance of warrants outstanding (in shares) 5,261 5,261
Warrants | Bought Deal Public Offering    
Changes in derivative financial liabilities [Roll Forward]    
Beginning balance of derivative financial liabilities $ 8,948 $ 7,405
Conversion to equity (common shares) upon exercise of warrants   (12,421)
Revaluation of derivative warrant liability upon exercise of warrants   (3,844)
Revaluation of derivative warrant liability 6,527 17,808
Ending balance of derivative financial liabilities $ 15,475 $ 8,948
Changes in warrants [Roll Forward]    
Beginning balance of warrants outstanding (in shares) 3,523 6,388
Conversion to equity (common shares) upon exercise of warrants (in shares)   (2,865)
Ending balance of warrants outstanding (in shares) 3,523 3,523
Warrants | February 14, 2014 Warrants    
Changes in derivative financial liabilities [Roll Forward]    
Beginning balance of derivative financial liabilities $ 2,845 $ 1,733
Conversion to equity (common shares) upon exercise of warrants   (8,848)
Revaluation of derivative warrant liability upon exercise of warrants   (1,013)
Revaluation of derivative warrant liability 3,427 10,973
Ending balance of derivative financial liabilities $ 6,272 $ 2,845
Changes in warrants [Roll Forward]    
Beginning balance of warrants outstanding (in shares) 1,738 3,748
Conversion to equity (common shares) upon exercise of warrants (in shares)   (2,010)
Ending balance of warrants outstanding (in shares) 1,738 1,738