Net Loss Per Share - Equity Shares Excluded from Calculation of Diluted Net Loss per Share Attributable to Common Stockholders (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of loss per share amount	2,237,910	2,048,738	1,321,890
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of loss per share amount	187,989	153,352	112,637
Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of loss per share amount	116,350	116,350	108,267