Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plans, Employee Stock Purchase Plan and Stock-Based Compensation - Summary of Option Activity (Details)

v3.20.1
Equity Incentive Plans, Employee Stock Purchase Plan and Stock-Based Compensation - Summary of Option Activity (Details) - 2004 and 2018 Equity Incentive Plan - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Outstanding Options, Beginning Balance 3,111,718 835,320  
Outstanding Options Granted 1,167,070 2,312,821  
Outstanding Options Exercised (35,204) (20,009)  
Outstanding Options Canceled or Forfeited (370,920) (16,414)  
Outstanding Options, Ending Balance 3,872,664 3,111,718 835,320
Outstanding Options Exercisable 1,713,295    
Weighted - Average Exercise Price, Beginning Balance $ 13.74 $ 10.31  
Weighted - Average Exercise Price, Granted 10.86 14.85  
Weighted - Average Exercise Price, Exercised 5.10 6.53  
Weighted - Average Exercise Price, Canceled or Forfeited 14.33 14.49  
Weighted - Average Exercise Price, Ending Balance 12.89 $ 13.74 $ 10.31
Weighted - Average Exercise Price, Exercisable $ 12.49    
Weighted - Average Remaining Contract Term 7 years 10 months 17 days 8 years 9 months 3 days 6 years 10 months 2 days
Weighted - Average Remaining Contract Term 6 years 7 months 6 days    
Aggregate Intrinsic Value, Balance $ 2,119 $ 1,088 $ 3,813
Aggregate Intrinsic Value, Exercisable $ 1,531