Organization and Description of Business - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Organization and Description of Business [Line Item]
Accumulated deficit	$ 288,081		$ 260,723
Cash and cash equivalents	76,963		$ 28,122
Working capital	71,500
Aggregate offering price	200,000
Proceeds from issuance of common stock	60,536	$ 0
Proceeds from issuance of common stock, deducting underwriting discounts, commissions, and other offering costs	60,100
Aggregate offering price, remaining	$ 132,600
Common Stock
Organization and Description of Business [Line Item]
Issuance of common stock in public offering, net (in shares)	18,400,000
SFJ Pharmaceuticals X, Ltd.
Organization and Description of Business [Line Item]
Proceeds from partnership contribution	$ 27,700
Equity Distribution Agreement with Citigroup Global Markets Inc. and William Blair & Company, L.L.C.
Organization and Description of Business [Line Item]
Aggregate offering price	60,000
Proceeds from issuance of common stock	2,900
Aggregate offering price, remaining	$ 57,000
Equity Distribution Agreement with Citigroup Global Markets Inc. and William Blair & Company, L.L.C. | Common Stock
Organization and Description of Business [Line Item]
Issuance of common stock in public offering, net (in shares)	561,848