Common Stock - Additional Information (Detail)		1 Months Ended					3 Months Ended	12 Months Ended
	Mar. 26, 2021 USD ($) $ / shares shares	Nov. 30, 2020 USD ($) shares	Jun. 19, 2020 USD ($) Affiliate $ / shares shares	Apr. 30, 2019 USD ($) $ / shares shares	Feb. 28, 2019 USD ($) shares	May 31, 2016 USD ($) $ / shares shares	Mar. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) shares	Apr. 08, 2021 $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Nov. 09, 2020 USD ($)	Mar. 31, 2020 $ / shares	Feb. 28, 2018 USD ($)
Class Of Stock [Line Items]
Common stock, shares authorized							50,000,000			50,000,000
Common stock, shares issued							34,360,775			26,883,000
Common stock, shares outstanding							34,360,775			26,883,000
Common stock, par value | $ / shares							$ 0.001			$ 0.001
Gross proceeds from common stock and warrant issued | $							$ 213,000,000.0
Proceeds from issuance of preferred stock | $							213,000,000.0
Proceeds from issuance of debt securities | $							213,000,000.0
Proceeds from issuance of warrants | $							$ 213,000,000.0
Stock price | $ / shares							$ 7.32
Common stock sales agreement, aggregate offering amount | $							$ 34,000			$ 27,000
Cash proceeds in connection with warrants exercised | $							$ 3,092,000
Common Stock
Class Of Stock [Line Items]
Stock issued during period, shares							331,000
PIPE Warrants
Class Of Stock [Line Items]
Stock price | $ / shares						$ 8.90	$ 7.32			$ 5.77
Subsequent Event
Class Of Stock [Line Items]
Stock price | $ / shares									$ 7.01
Offering Warrants
Class Of Stock [Line Items]
Warrants exercise price | $ / shares							12.50					$ 12.50
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares							$ 12.50					$ 12.50
Offering Warrants | Subsequent Event
Class Of Stock [Line Items]
Warrants to purchase of common stock shares									2,252,609
Warrants exercise price | $ / shares									$ 12.50
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares									$ 12.50
Leerink Capital Partners LLC
Class Of Stock [Line Items]
Stock issued during period, shares								470,777
Net proceeds from issuance of common stock | $								$ 10,300,000
Common stock value available for issuance in connection with future stock sales | $							$ 22,200,000
Leerink Capital Partners LLC | Common Stock
Class Of Stock [Line Items]
Stock issued during period, shares		1,070,175			1,251,555		330,688
Net proceeds from issuance of common stock | $		$ 5,900,000			$ 7,500,000		$ 3,400,000
Underwritten Public Offering
Class Of Stock [Line Items]
Common stock, shares issued	6,900,000		9,725,000	2,173,913			247,391
Gross proceeds from common stock and warrant issued | $	$ 55,200,000		$ 51,100,000
Net proceeds from public offering | $	51,600,000		$ 47,700,000	$ 22,800,000
Number Of Affiliates Stockholders | Affiliate			3
Number of other stockholders | Affiliate			2
Percentage Of affiliates stockholders			5.00%
Net proceeds from public offering | $	$ 51,600,000		$ 47,700,000	22,800,000
Gross proceeds from common stock and warrant issued | $				$ 25,000,000.0			$ 3,100,000
Percentage of beneficial ownership of voting securities				5.00%
Underwritten Public Offering | Offering Warrants
Class Of Stock [Line Items]
Warrants to purchase of common stock shares				2,500,000
Warrants exercise price | $ / shares				$ 12.50
Warrants exercisable period				2 years
Class of warrant or right, outstanding							2,252,609
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares				$ 12.50
Warrants exercisable period				2 years
Underwritten Public Offering | New Enterprise Associates and Another Stockholder
Class Of Stock [Line Items]
Common stock, shares issued			4,503,571
Underwritten Public Offering | Other Investors
Class Of Stock [Line Items]
Common stock, shares issued				434,782
Underwritten Public Offering | Other Investors | Offering Warrants
Class Of Stock [Line Items]
Warrants to purchase of common stock shares				434,782
Over Allotment Option
Class Of Stock [Line Items]
Warrants to purchase of common stock shares	900,000		1,225,000
Over Allotment Option | Offering Warrants
Class Of Stock [Line Items]
Warrants to purchase of common stock shares				326,086
Private Placement | PIPE Warrants
Class Of Stock [Line Items]
Common stock, shares issued						1,764,242,000
Shares issued, price per share | $ / shares						$ 9.65
Warrants exercise price | $ / shares						$ 10.00
Warrants exercisable period						5 years
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares						$ 10.00
Gross proceeds from issuance of private placement | $						$ 17,000,000.0
Exchange of unit to share						1
Warrants exercisable period						5 years
Warrants exercisable shares of common stock exercised							80,309
Cash proceeds in connection with warrants exercised | $							$ 800,000
Warrants exercisable shares of common stock outstanding							1,683,933
Private Placement | PIPE Warrants | Director and Executive Officer
Class Of Stock [Line Items]
Common stock, shares issued						54,402
Net offering proceeds to the company | $						$ 15,400,000
Minimum
Class Of Stock [Line Items]
Shares issued, price per share | $ / shares	$ 8.00		$ 5.25
Minimum | Underwritten Public Offering
Class Of Stock [Line Items]
Shares issued, price per share | $ / shares				$ 11.40
Minimum | Underwritten Public Offering | Offering Warrants
Class Of Stock [Line Items]
Shares issued, price per share | $ / shares				$ 0.10
Maximum [Member]
Class Of Stock [Line Items]
Offering, issuance and sale of stocks and securities, shelf registration | $											$ 300,000,000.0
Maximum [Member] | Leerink Capital Partners LLC
Class Of Stock [Line Items]
Common stock sales agreement, aggregate offering amount | $													$ 50,000,000.0
Common stock sales agreement commission, percentage													3.00%