Common Stock, Redeemable Common Stock and Convertible Preferred Stock (converted to Common Stock) - Additional Information (Details) - USD ($)					1 Months Ended	12 Months Ended
	Oct. 14, 2020	Aug. 07, 2020	Nov. 26, 2019	Apr. 12, 2019	Aug. 31, 2015	Dec. 31, 2020	Jun. 10, 2020	Dec. 31, 2019	Nov. 29, 2019	Apr. 16, 2019
Class of Stock [Line Items]
Common stock par value (in dollars per share)						$ 0.001	$ 0.001	$ 0.001
Common stock, authorized (in shares)						125,000,000		33,333,333
Cash dividends						$ 0
Stock issued (in shares)			3,666,667	5,670,000
Sale price (in dollars per share)			$ 12.00	$ 11.00
Warrant expiration period			30 days	5 years
Proceeds from common stock issuance			$ 65,000,000.0	$ 85,800,000
Fair value of additional common stock issued					$ 734,000
Preferred stock outstanding						$ 0
Equity Unit Purchase Agreements
Class of Stock [Line Items]
Purchase agreement, term	36 months
Common Stock | Equity Unit Purchase Agreements
Class of Stock [Line Items]
Number of shares authorized in transaction, amount	$ 50,000,000.0
Sales Agents [Member] | Common Stock
Class of Stock [Line Items]
Number of shares authorized in transaction, amount		$ 50,000,000.0
Maximum
Class of Stock [Line Items]
Common stock, authorized (in shares)							125,000,000
Minimum
Class of Stock [Line Items]
Common stock, authorized (in shares)							33,333,333
Series Seed Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (in shares)						10,000,000
Preferred stock par value (in dollars per share)						$ 0.001		$ 0.001
Genzyme Agreement
Class of Stock [Line Items]
Shares issued for additional consideration (in shares)					107,371
Common stock purchase price (in dollars per share)					$ 0.001
Pre Funded Warrant
Class of Stock [Line Items]
Common stock par value (in dollars per share)										$ 0.001
Number of warrants issued (in shares)			1,750,000	2,130,000
Convertible preferred stock exercise price (in dollars per share)			$ 11.999	$ 10.999					$ 11.999	10.999
Pre Funded Warrant | Minimum
Class of Stock [Line Items]
Convertible preferred stock exercise price (in dollars per share)						$ 0.001
Class A Warrant
Class of Stock [Line Items]
Number of warrants issued (in shares)				3,900,000
Convertible preferred stock exercise price (in dollars per share)				$ 13.20						$ 13.20
Class B Warrants
Class of Stock [Line Items]
Number of warrants issued (in shares)			5,416,667
Convertible preferred stock exercise price (in dollars per share)			$ 15.00						$ 15.00