XML 43 R33.htm IDEA: XBRL DOCUMENT v3.7.0.1
Equity - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock option outstanding 6,747,024   6,747,024   5,136,110
Stock options, granted     1,993,998    
Unrecognized stock-based compensation cost $ 7,700,000   $ 7,700,000    
Unrecognized share-based compensation expense, weighted-average recognition period     1 year 3 months 18 days    
Stock compensation expense (gain) $ 1,922,000 $ 1,560,000 $ 3,052,000 $ 2,348,000  
Warrant [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants outstanding 0   0   450,000
Research And Development Expense [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock compensation expense (gain) $ 285,000 372,000 $ 327,000 363,000  
Research And Development Expense [Member] | Warrant [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock compensation expense (gain) $ 0 $ 74,000 $ 0 $ (10,000)  
Non-Employees [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options, granted     1,240,834    
Stock option vested     453,333    
Stock option unvested 787,501   787,501    
Unrecognized stock-based compensation cost $ 1,600,000   $ 1,600,000