Annual report pursuant to Section 13 and 15(d)

Common Stock - Summary of Stock Options Outstanding Regarding Number of Common Shares Issuable upon Exercise of Vested Options (Detail)

v3.20.1
Common Stock - Summary of Stock Options Outstanding Regarding Number of Common Shares Issuable upon Exercise of Vested Options (Detail)
 12 Months Ended
Dec. 31, 2019
$ / shares
shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 325,379
Exercise Price Range, Weighted Average Vested Price $ 22.93
Exercise Price Range, Weighted Average Remaining Contractual Term 8 years 5 months 4 days
Range one [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 34,826
Exercise Price Range, Weighted Average Vested Price $ 1.42
Exercise Price Range, Weighted Average Remaining Contractual Term 9 years 29 days
Exercise Price Range, Lower Range Limit $ 1.42
Exercise Price Range, Upper Range Limit $ 1.99
Range two [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 162,076
Exercise Price Range, Weighted Average Vested Price $ 2.56
Exercise Price Range, Weighted Average Remaining Contractual Term 8 years 8 months 19 days
Exercise Price Range, Lower Range Limit $ 2.00
Exercise Price Range, Upper Range Limit $ 2.97
Range three [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 59,410
Exercise Price Range, Weighted Average Vested Price $ 3.37
Exercise Price Range, Weighted Average Remaining Contractual Term 8 years 6 months 25 days
Exercise Price Range, Lower Range Limit $ 2.98
Exercise Price Range, Upper Range Limit 3.37
Range four [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit 3.38
Exercise Price Range, Upper Range Limit 3.70
Range five [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit 3.71
Exercise Price Range, Upper Range Limit $ 16.46
Range six [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 63,144
Exercise Price Range, Weighted Average Vested Price $ 28.90
Exercise Price Range, Weighted Average Remaining Contractual Term 7 years 6 months 29 days
Exercise Price Range, Lower Range Limit $ 16.47
Exercise Price Range, Upper Range Limit $ 69.45
Range seven [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 2,190
Exercise Price Range, Weighted Average Vested Price $ 186.98
Exercise Price Range, Weighted Average Remaining Contractual Term 5 years 6 months 25 days
Exercise Price Range, Lower Range Limit $ 69.46
Exercise Price Range, Upper Range Limit $ 206.25
Range eight [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 853
Exercise Price Range, Weighted Average Vested Price $ 465.93
Exercise Price Range, Weighted Average Remaining Contractual Term 4 years 5 months 19 days
Exercise Price Range, Lower Range Limit $ 206.26
Exercise Price Range, Upper Range Limit $ 1,286.45
Range nine [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 1,530
Exercise Price Range, Weighted Average Vested Price $ 1,304.27
Exercise Price Range, Weighted Average Remaining Contractual Term 3 years 9 months 10 days
Exercise Price Range, Lower Range Limit $ 1,286.46
Exercise Price Range, Upper Range Limit $ 1,348.05
Range ten [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Vested Options | shares 1,350
Exercise Price Range, Weighted Average Vested Price $ 1,605.51
Exercise Price Range, Weighted Average Remaining Contractual Term 1 year 7 months 13 days
Exercise Price Range, Lower Range Limit $ 1,348.06
Exercise Price Range, Upper Range Limit $ 1,960.20