Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Shareholders' Equity and Capital Stock - addl information (Details)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended 9 Months Ended
Sep. 30, 2018
USD ($)
Mar. 30, 2018
shares
Sep. 30, 2017
USD ($)
Jun. 30, 2018
shares
Sep. 30, 2018
USD ($)
shares
Sep. 30, 2017
USD ($)
shares
Sep. 30, 2018
$ / shares
Sep. 30, 2018
USD ($)
$ / shares
shares
Sep. 25, 2018
shares
Dec. 31, 2017
$ / shares
shares
Stockholder's Equity Note [Line Items]                    
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Intrinsic Value | $               $ 1,146    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period         420,344          
Stock Issued During Period, Shares, New Issues         1,536,169          
Share Price | (per share)             $ 1.05 $ 0.76    
Payments Of Stock Issuance Costs | $         $ 731 $ 60        
Number of RSUs Vested         80,514          
Stock Issued During Period, Value, New Issues | $         $ 7,443          
Percent or RSUs that vest         80,514          
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Number               9,625,371   9,459,401
stock options exercisable               5,286,040    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number               6,288,801    
Stock based compensation | $ $ 100   $ 200   $ 727 705        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | $         500          
Proceeds from Stock Options Exercised | $ $ 100       $ 247 $ 349        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period         240,909          
Granted, Options         1,263,597          
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares               $ 1.00   $ 0.97
Capital Stock                    
Stockholder's Equity Note [Line Items]                    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period         420,344,000          
Stock Issued During Period, Shares, New Issues         12,195,122          
Stock Issued During Period, Value, New Issues | $         $ 7,443          
Warrants                    
Stockholder's Equity Note [Line Items]                    
Number of securities called by each unit                 13,062,878  
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares               $ 0.01    
In Money Stock Option [Member]                    
Stockholder's Equity Note [Line Items]                    
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Number               8,622,610    
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options | $               $ 900    
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition         2 years 6 months          
Restricted Stock Units (RSUs) [Member]                    
Stockholder's Equity Note [Line Items]                    
Number of RSUs Vested   62,000                
Percent or RSUs that vest   62,000                
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Share-based Awards Other than Options | $               $ 500    
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition         1 year 4 months 24 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    
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] | 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%