CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	At The Market	Common Stock	Common Stock At The Market	Additional Paid-In Capital	Additional Paid-In Capital At The Market	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2019	$ 73,121		$ 2		$ 235,049		$ (161,950)	$ 20
Beginning balance, shares at Dec. 31, 2019			21,833,037
Issuance of common stock, net of issuance costs	69,842	$ 3,768			69,842	$ 3,768
Issuance of common stock, net of issuance costs, shares			2,500,000	188,700
Issuances of common stock from employee stock plans	1,851				1,851
Issuances of common stock from employee stock plans, shares			251,624
Stock-based compensation	8,686				8,686
Foreign currency translation gain (loss)	(249)							(249)
Unrealized gain (loss) on marketable securities	52							52
Net loss	(52,892)						(52,892)
Ending balance at Dec. 31, 2020	$ 104,179		$ 2		319,196		(214,842)	(177)
Ending balance, shares at Dec. 31, 2020	24,773,361		24,773,361
Issuance of common stock, net of issuance costs	$ 134,770	$ 4,690	$ 1		134,769	$ 4,690
Issuance of common stock, net of issuance costs, shares			4,356,060	214,971
Issuances of common stock from employee stock plans	2,022				2,022
Issuances of common stock from employee stock plans, shares			210,727
Stock-based compensation	9,952				9,952
Foreign currency translation gain (loss)	258							258
Unrealized gain (loss) on marketable securities	(287)							(287)
Net loss	(69,204)						(69,204)
Ending balance at Dec. 31, 2021	$ 186,380		$ 3		$ 470,629		$ (284,046)	$ (206)
Ending balance, shares at Dec. 31, 2021	29,555,119		29,555,119