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

Derivative warrant liabilities - Private placement offering narrative (Details)

v3.19.1
Derivative warrant liabilities - Private placement offering narrative (Details) - USD ($)
12 Months Ended
Feb. 14, 2014
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure of classes of share capital [line items]        
Net proceeds from issuance of common shares   $ 0 $ 162,324,000  
Proceeds from exercise of derivative warrants   0 8,684,000  
Derivative warrant liabilities (notes 11 and 23)   $ 21,747,000 11,793,000  
Warrants        
Disclosure of classes of share capital [line items]        
Revaluation of derivative warrant liability upon exercise of warrants     $ 4,857,000  
Number of warrants exercised   1,172,000 85,000  
Derivative warrant liabilities (notes 11 and 23)   $ 21,747,000 $ 11,793,000 $ 9,138,000
Warrants | Private Placement Offering Feb 14 2014        
Disclosure of classes of share capital [line items]        
Increase (decrease) through exercise of share purchase warrants     8,848,000  
Gains (losses) recognised in profit or loss, fair value measurement, liabilities     1,013,000  
Derivative warrant liabilities (note 10)   $ 6,272,000 $ 2,845,000  
Net proceeds from issuance of common shares $ 52,000,000      
Number of units issued 18,919,404      
Share issuance, price per share (in dollars per share) $ 2.7485      
Private placement, number of shares per Unit 0.25      
Warrant exercise period 5 years      
Exercise price, price per unit (in dollars per share) $ 3.2204      
Issued pursuant to exercise of warrants (in shares)     1,154,000  
Number of cashless warrants exercised (in shares)     1,983,000  
Fair value of warrants on exercise dates     $ 9,861,000  
Revaluation of derivative warrant liability upon exercise of warrants     $ 1,013,000  
Number of warrants exercised   0 27,000  
Proceeds from exercise of derivative warrants     $ 88,000  
Derivative warrant liabilities (notes 11 and 23)   $ 6,272,000 2,845,000 $ 1,733,000
Revaluation of derivative warrant liability   $ 3,427,000 10,973,000  
Common shares        
Disclosure of classes of share capital [line items]        
Net proceeds from issuance of common shares     $ (162,324,000)  
Issued pursuant to exercise of warrants (in shares)   1,172,000 85,000  
Common shares | Private Placement Offering Feb 14 2014        
Disclosure of classes of share capital [line items]        
Issued pursuant to exercise of warrants (in shares)     27,000  
Level 3 of fair value hierarchy | Warrants | Private Placement Offering Feb 14 2014        
Disclosure of classes of share capital [line items]        
Information about how expected ten percent increase in market price would increase fair value of derivative warrant liability   $ 3,407,000    
Information about how expected ten percent decrease in market price would decrease fair value of derivative warrant liability   3,370,000    
Information about how expected ten percent increase in volatility would increase fair value of derivative warrant liability   344,000    
Information about how expected ten percent decrease in volatility would decrease fair value of derivative warrant liability   $ 322,000    
Common units | Common shares | Private Placement Offering Feb 14 2014        
Disclosure of classes of share capital [line items]        
Private placement, number of shares per Unit 1      
Top of range | Level 3 of fair value hierarchy | Warrants | Private Placement Offering Feb 14 2014        
Disclosure of classes of share capital [line items]        
Change in risk variable   10.00%    
Change in risk variable   10.00%    
Bottom of range | Level 3 of fair value hierarchy | Warrants | Private Placement Offering Feb 14 2014        
Disclosure of classes of share capital [line items]        
Change in risk variable   (10.00%)    
Change in risk variable   (10.00%)