Basic and Diluted Net Loss Per Common Share - Summary of Computation of Diluted Net Loss Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in share)	87,309	82,193	87,309	82,193
Stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in share)	53,412	69,847	53,412	69,847
RSUs outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in share)	30,731	10,844	30,731	10,844
Stock warrants outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in share)	264	324	264	324
Convertible Preferred Stock outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in share)	0	0	0	0
Unregistered restricted stock awards outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in share)	632	500	632	500
2020 ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in share)	2,270	678	2,270	678