Quarterly report pursuant to Section 13 or 15(d)

Summary of Unvested Stock Option Activity (Detail)

v3.19.2
Summary of Unvested Stock Option Activity (Detail) - $ / shares
shares in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Weighted Average Grant Date Fair Value        
Granted $ 1.53 $ 1.27 $ 1.53 $ 1.46
Stock Options        
Shares        
Beginning Balance     522  
Granted     70  
Vested     (147)  
Forfeited or cancelled     (78)  
Ending Balance 367   367  
Weighted Average Grant Date Fair Value        
Beginning Balance     $ 2.11  
Granted     1.53  
Vested     2.94  
Forfeited or cancelled     2.62  
Ending Balance $ 1.56   $ 1.56