Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Roll Forward of Non-Vested Stock Options Activity (Detail)

v3.19.3.a.u2
Stock-Based Compensation - Roll Forward of Non-Vested Stock Options Activity (Detail) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Payment Arrangement [Abstract]      
Number of options, outstanding 4,330,526    
Granted 969,720 2,457,102 2,119,498
Number of options, vested (2,067,559)    
Number of options, forfeited (175,928)    
Number of options, outstanding 3,056,759 4,330,526  
Weighted average granted date fair value, outstanding (in dollars per share) $ 2.67    
Weighted average granted date fair value, granted (in dollars per share) 5.77    
Weighted average granted date fair value, vested (in dollars per share) 2.67    
Weighted average granted date fair value, forfeited (in dollars per share) 4.09    
Weighted average granted date fair value, outstanding (in dollars per share) $ 3.60 $ 2.67