Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands							1 Months Ended			3 Months Ended		9 Months Ended
	Nov. 02, 2020	Sep. 04, 2020	Jun. 16, 2020	Jun. 15, 2020	Jan. 02, 2019	Nov. 27, 2018	Sep. 30, 2021	Jun. 30, 2021	Feb. 28, 2021	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Net proceeds from issuance of common stock													$ 24,016
Offering costs												$ 66
ATM Facility
Class Of Stock [Line Items]
Net proceeds from issuance of common stock		$ 10,000
Offering costs										$ 300
Shelf Registration
Class Of Stock [Line Items]
Common stock issued, shares												0
Offering costs												$ 106,400
Shelf Registration | Maximum
Class Of Stock [Line Items]
Additional capital raised												$ 300,000
Public Offering
Class Of Stock [Line Items]
Common stock issued, shares	1,614,035
Net proceeds from issuance of common stock	$ 42,700
Shares price, per share	$ 28.50
Number of shares issued upon full exercise of options to underwriters	210,526
Underwriting discounts and other offering expenses	$ 3,300
Common Stock
Class Of Stock [Line Items]
Common stock issued, shares			411,112	3,804,817							4,215,929
Net proceeds from issuance of common stock			$ 4,600	$ 19,400
Warrants to purchase common stock			4,434
Common stock exercise price			$ 140.25
Common Stock | ATM Facility
Class Of Stock [Line Items]
Common stock issued, shares												0
Common Stock | Concurrent Financing Warrants
Class Of Stock [Line Items]
Common stock issued, shares							655,409	560,402	673,463
Warrants to purchase common stock				2,752,546			1,013,116	760,572	978,858	760,572		1,013,116
Common stock exercise price				$ 10.56
Warrants outstanding							0					0
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Stock issued					1,438,985	1,738,759	0					0		0	3,177,744	3,177,744
Net proceeds from issuance of convertible preferred stock					$ 4,900	$ 5,700
Conversion of convertible notes and accrued interest						$ 700
Preferred stock per share					$ 3.41
Convertible preferred stock description												All outstanding shares of Series A convertible preferred stock were converted into shares of common stock on a one for one ratio in connection with the closing of the Merger on June 15, 2020