Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity and Capital Stock - addl information (Details)

v3.8.0.1
Shareholders' Equity and Capital Stock - addl information (Details)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2017
USD ($)
shares
Sep. 30, 2016
USD ($)
shares
Sep. 30, 2017
CAD / shares
Sep. 30, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
$ / shares
shares
Stockholder's Equity Note [Line Items]              
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period     549,952        
Stock Issued During Period, Shares, New Issues     1,536,169        
Share Price | (per share)         CAD 0.72 $ 0.76  
Payments Of Stock Issuance Costs | $     $ 60 $ 880      
Stock Issued During Period, Value, New Issues | $     $ 1,081        
Percent or RSUs that vest     337,380        
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Number           8,342,850 9,748,934
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number           6,629,270  
Stock based compensation | $ $ 200 $ 200 $ 705 603      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | $     700        
Proceeds from Stock Options Exercised | $     $ 349 $ 9      
Granted, Options     500,000        
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares           $ 0.97 $ 0.97
Capital Stock              
Stockholder's Equity Note [Line Items]              
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period     549,952        
Stock Issued During Period, Shares, New Issues     1,536,169        
Stock Issued During Period, Value, New Issues | $     $ 1,081        
In Money Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options | $           $ 500  
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition     1 year        
Restricted Stock Units (RSUs) [Member]              
Stockholder's Equity Note [Line Items]              
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Share-based Awards Other than Options | $           $ 300  
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition     1 year 1 month 6 days        
Granted, Options     0 0      
Restricted Stock Units (RSUs) [Member] | Capital Stock              
Stockholder's Equity Note [Line Items]              
Number of securities called by each unit           1  
Employee Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Granted, Options     0 0      
Grant Date [Member] | Employee Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     10.00%        
Four and One Half Months After Grant [Member] | Restricted Stock Units (RSUs) [Member]              
Stockholder's Equity Note [Line Items]              
Stock Option Vesting Period     4 months 15 days        
Four and One Half Months After Grant [Member] | Employee Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     22.00%        
Nine Months After Grant [Member] | Restricted Stock Units (RSUs) [Member]              
Stockholder's Equity Note [Line Items]              
Stock Option Vesting Period     9 months        
Nine Months After Grant [Member] | Employee Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     22.00%        
Thirteen and One Half Months After Grant [Member] | Restricted Stock Units (RSUs) [Member]              
Stockholder's Equity Note [Line Items]              
Stock Option Vesting Period     13 months 15 days        
Thirteen and One Half Months After Grant [Member] | Employee Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     22.00%        
Eighteen Months After Date Of Grant [Member] | Employee Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     24.00%        
First Anniversary [Member]              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     33.30%        
First Anniversary [Member] | Employee Stock Option [Member]              
Stockholder's Equity Note [Line Items]              
Stock Option Vesting Period     3 years        
Second Anniversary [Member]              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     33.30%        
Third Anniversary (Member)              
Stockholder's Equity Note [Line Items]              
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage     33.40%