Net Loss Per Share - Summary of Potentially Dilutive Shares Excluded From The Calculation of Diluted Net Loss (Detail) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,073,044	812,539
Unvested restricted common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		5,376
Redeemable convertible preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	14,948,249	6,365,368