Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plans and Stock Based Compensation - Stock Options Outstanding and Exercisable by Exercise Price (Detail)

v3.20.1
Equity Incentive Plans and Stock Based Compensation - Stock Options Outstanding and Exercisable by Exercise Price (Detail)
12 Months Ended
Dec. 31, 2019
$ / shares
shares
$0.42 - 1.85  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices $ 0.42
Range of Exercise Prices $ 1.85
Number Outstanding | shares 478,366
Weighted Average Remaining Contractual Life (Years) 3 years 9 months 18 days
Weighted Average Exercise Price $ 1.07
Number Exercisable | shares 475,308
Weighted Average Exercise Price $ 1.06
$4.04 - 4.28  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 4.04
Range of Exercise Prices $ 4.28
Number Outstanding | shares 6,681
Weighted Average Remaining Contractual Life (Years) 7 years 8 months 19 days
Weighted Average Exercise Price $ 4.22
Number Exercisable | shares 4,191
Weighted Average Exercise Price $ 4.20
$4.66 - 4.66  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 4.66
Range of Exercise Prices $ 4.66
Number Outstanding | shares 1,030,126
Weighted Average Remaining Contractual Life (Years) 9 years 1 month 9 days
Weighted Average Exercise Price $ 4.66
Number Exercisable | shares 105,638
Weighted Average Exercise Price $ 4.66
$4.74 - 5.81  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 4.74
Range of Exercise Prices $ 5.81
Number Outstanding | shares 428,825
Weighted Average Remaining Contractual Life (Years) 8 years 11 months 4 days
Weighted Average Exercise Price $ 5.06
Number Exercisable | shares 73,716
Weighted Average Exercise Price $ 5.16
$6.31 - 6.31  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 6.31
Range of Exercise Prices $ 6.31
Number Outstanding | shares 1,227,849
Weighted Average Remaining Contractual Life (Years) 8 years 4 months 28 days
Weighted Average Exercise Price $ 6.31
Number Exercisable | shares 531,659
Weighted Average Exercise Price $ 6.31
$6.54 - 8.21  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 6.54
Range of Exercise Prices $ 8.21
Number Outstanding | shares 537,662
Weighted Average Remaining Contractual Life (Years) 8 years 9 months 10 days
Weighted Average Exercise Price $ 7.63
Number Exercisable | shares 123,674
Weighted Average Exercise Price $ 8.03
$8.35 - 9.28  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 8.35
Range of Exercise Prices $ 9.28
Number Outstanding | shares 134,450
Weighted Average Remaining Contractual Life (Years) 9 years 6 months 21 days
Weighted Average Exercise Price $ 8.53
Number Exercisable | shares 7,499
Weighted Average Exercise Price $ 9.24
$9.40 - 9.40  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 9.40
Range of Exercise Prices $ 9.40
Number Outstanding | shares 537,500
Weighted Average Remaining Contractual Life (Years) 7 years 9 months 7 days
Weighted Average Exercise Price $ 9.40
Number Exercisable | shares 348,437
Weighted Average Exercise Price $ 9.40
$10.78 - 61.27  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 10.78
Range of Exercise Prices $ 61.27
Number Outstanding | shares 360,713
Weighted Average Remaining Contractual Life (Years) 8 years 8 months 15 days
Weighted Average Exercise Price $ 12.58
Number Exercisable | shares 107,976
Weighted Average Exercise Price $ 13.22
$70.29 - 70.29  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 70.29
Range of Exercise Prices $ 70.29
Number Outstanding | shares 1,818
Weighted Average Remaining Contractual Life (Years) 2 years 4 months 13 days
Weighted Average Exercise Price $ 70.29
Number Exercisable | shares 1,818
Weighted Average Exercise Price $ 70.29
$0.42 - 70.29  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices 0.42
Range of Exercise Prices $ 70.29
Number Outstanding | shares 4,743,990
Weighted Average Remaining Contractual Life (Years) 8 years 1 month 28 days
Number Exercisable | shares 1,779,916
Weighted Average Exercise Price $ 5.98