Net Loss per Share - Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-Average Shares (Detail) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents outstanding excluded from diluted earnings per share calculation	2,460,180	1,534,688
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents outstanding excluded from diluted earnings per share calculation	2,116,662	1,332,097
ESPP [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents outstanding excluded from diluted earnings per share calculation	9,053	10,430
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents outstanding excluded from diluted earnings per share calculation	48,683	48,683
Restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents outstanding excluded from diluted earnings per share calculation	285,782	143,478