CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total
Beginning balance (in shares) at Dec. 31, 2021	201,988,662
Beginning balance at Dec. 31, 2021	$ 2,020	$ 1,103,224	$ (614)	$ (557,375)	$ 547,255
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock and common stock warrants, net of issuance costs (in shares)	33,333,336
Issuance of common stock and common stock warrants, net of issuance costs	$ 333	138,675			139,008
Issuance of common stock upon exercise of warrants (in shares)	4,677
Issuance of common stock upon exercise of warrants		3			3
Non-cash stock-based compensation		8,264			8,264
Stock-based awards and related share issuances, net ( in shares)	(160,724)
Stock-based awards and related share issuances, net		(286)			(286)
Other comprehensive income (loss)			(1,642)		(1,642)
Net loss				(28,834)	(28,834)
Ending balance (in shares) at Jun. 30, 2022	235,165,951
Ending balance at Jun. 30, 2022	$ 2,353	1,249,880	(2,256)	(586,209)	663,768
Beginning balance (in shares) at Mar. 31, 2022	201,752,722
Beginning balance at Mar. 31, 2022	$ 2,019	1,107,051	(1,587)	(573,048)	534,435
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock and common stock warrants, net of issuance costs (in shares)	33,333,336
Issuance of common stock and common stock warrants, net of issuance costs	$ 333	138,675			139,008
Non-cash stock-based compensation		4,220			4,220
Stock-based awards and related share issuances, net ( in shares)	79,893
Stock-based awards and related share issuances, net	$ 1	(66)			(65)
Other comprehensive income (loss)			(669)		(669)
Net loss				(13,161)	(13,161)
Ending balance (in shares) at Jun. 30, 2022	235,165,951
Ending balance at Jun. 30, 2022	$ 2,353	1,249,880	(2,256)	(586,209)	$ 663,768
Beginning balance (in shares) at Dec. 31, 2022	237,166,625				237,166,625
Beginning balance at Dec. 31, 2022	$ 2,372	1,259,527	(1,040)	(655,382)	$ 605,477
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash stock-based compensation		8,620			8,620
Stock-based awards and related share issuances, net ( in shares)	480,806
Stock-based awards and related share issuances, net	$ 5	(5)			0
Other comprehensive income (loss)			1,040		1,040
Net loss				(32,038)	$ (32,038)
Ending balance (in shares) at Jun. 30, 2023	237,647,431				237,647,431
Ending balance at Jun. 30, 2023	$ 2,377	1,268,142		(687,420)	$ 583,099
Beginning balance (in shares) at Mar. 31, 2023	237,261,164
Beginning balance at Mar. 31, 2023	$ 2,373	1,264,203	(115)	(673,000)	593,461
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash stock-based compensation		3,943			3,943
Stock-based awards and related share issuances, net ( in shares)	386,267
Stock-based awards and related share issuances, net	$ 4	(4)
Other comprehensive income (loss)			$ 115		115
Net loss				(14,420)	$ (14,420)
Ending balance (in shares) at Jun. 30, 2023	237,647,431				237,647,431
Ending balance at Jun. 30, 2023	$ 2,377	$ 1,268,142		$ (687,420)	$ 583,099