Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plans and Stock Based Compensation - Summary of Stock Option Activity Under Equity Incentive Plan (Detail)

v3.20.4
Equity Incentive Plans and Stock Based Compensation - Summary of Stock Option Activity Under Equity Incentive Plan (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Outstanding Options Number of Shares, Beginning Balance 4,763,062 4,002,999  
Number of Shares, Options granted 2,453,506 2,023,600  
Number of Shares, Options exercised (261,260) (286,479)  
Number of shares, Options cancelled (257,381) (977,058)  
Outstanding Options Number of Shares, Ending Balance 6,697,927 4,763,062 4,002,999
Outstanding Options Number of Shares, Vested and expected to vest, December 31, 2020 6,697,927    
Outstanding Options Number of Shares, Exercisable at December 31, 2020 2,845,501    
Weighted Average Exercise Price, Beginning Balance $ 6.36 $ 10.43  
Weighted Average Exercise Price, Options granted 14.06 6.00  
Weighted Average Exercise Price, Options exercised 3.99 6.10  
Weighted Average Exercise Price, Options cancelled 9.99 22.39  
Weighted Average Exercise Price, Ending Balance 9.13 $ 6.36 $ 10.43
Weighted Average Exercise Price, Vested and expected to vest, December 31, 2020 9.13    
Weighted Average Exercise Price, Exercisable at December 31, 2020 $ 6.66    
Weighted-Average Remaining Contractual Term, Outstanding 7 years 9 months 3 days 8 years 1 month 6 days 6 years 4 months 24 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest, December 31, 2020 7 years 9 months 3 days    
Weighted-Average Remaining Contractual Term, Exercisable at December 31, 2020 6 years 8 months 4 days    
Aggregate Intrinsic Value, Outstanding $ 13,790 $ 36,630 $ 1,500
Aggregate Intrinsic Value, Vested and expected to vest, December 31, 2020 13,790    
Aggregate Intrinsic Value, Exercisable at December 31, 2020 $ 8,850