CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	ATM Facility	Common Stock	Common Stock ATM Facility	Additional Paid-in Capital	Additional Paid-in Capital ATM Facility	Accumulated Other Comprehensive Loss Investments	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2020			140,449,647
Beginning balance at Dec. 31, 2020	$ (9,227)		$ 140		$ 306,554		$ 0	$ (315,921)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(55,512)							(55,512)
Share-based compensation	958				958
Exercise of stock options (in shares)			30,610
Exercises of stock options	39				39
Exercise of common stock warrants (in shares)			852,840
Exercises of common stock warrants	469		$ 1		468
Issuance of common stock and common stock warrants (in shares)				30,645,702
Issuance of common stock and common stock warrants	72,543			$ 31		$ 72,512
Ending balance (in shares) at Mar. 31, 2021			171,978,799
Ending balance at Mar. 31, 2021	9,270		$ 172		380,531		0	(371,433)
Beginning balance (in shares) at Dec. 31, 2020			140,449,647
Beginning balance at Dec. 31, 2020	(9,227)		$ 140		306,554		0	(315,921)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(80,954)
Unrealized loss of investments	0
Ending balance (in shares) at Jun. 30, 2021			188,460,951
Ending balance at Jun. 30, 2021	49,349		$ 188		446,036		0	(396,875)
Beginning balance (in shares) at Mar. 31, 2021			171,978,799
Beginning balance at Mar. 31, 2021	9,270		$ 172		380,531		0	(371,433)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(25,442)							(25,442)
Share-based compensation	1,260				1,260
Issuance of common stock and common stock warrants (in shares)				16,482,152
Issuance of common stock and common stock warrants		$ 64,261		$ 16		$ 64,245
Unrealized loss of investments	0
Ending balance (in shares) at Jun. 30, 2021			188,460,951
Ending balance at Jun. 30, 2021	49,349		$ 188		446,036		0	(396,875)
Beginning balance (in shares) at Dec. 31, 2021			199,463,645
Beginning balance at Dec. 31, 2021	171,710		$ 199		487,768		0	(316,257)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(807)							(807)
Share-based compensation	1,894				1,894
Ending balance (in shares) at Mar. 31, 2022			199,463,645
Ending balance at Mar. 31, 2022	172,797		$ 199		489,662		0	(317,064)
Beginning balance (in shares) at Dec. 31, 2021			199,463,645
Beginning balance at Dec. 31, 2021	171,710		$ 199		487,768		0	(316,257)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (32,767)
Exercise of stock options (in shares)	0
Exercise of common stock warrants (in shares)	0
Unrealized loss of investments	$ (281)
Ending balance (in shares) at Jun. 30, 2022			199,463,645
Ending balance at Jun. 30, 2022	142,358		$ 199		491,464		(281)	(349,024)
Beginning balance (in shares) at Mar. 31, 2022			199,463,645
Beginning balance at Mar. 31, 2022	172,797		$ 199		489,662		0	(317,064)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(31,960)							(31,960)
Share-based compensation	1,802				1,802
Unrealized loss of investments	(281)						(281)
Ending balance (in shares) at Jun. 30, 2022			199,463,645
Ending balance at Jun. 30, 2022	$ 142,358		$ 199		$ 491,464		$ (281)	$ (349,024)