CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated Other Comprehensive Loss	Accumulated deficit
Shares, beginning balance (in shares) at Dec. 31, 2020		369,797,524
Beginning balance at Dec. 31, 2020	$ 56,787	$ 37	$ 295,065	$ 0	$ (238,315)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and release of restricted stock units (in shares)		268,426
Issuance of common stock upon exercise of stock options and release of restricted stock units	12		12
Issuance of common stock upon exercise of warrants and other, net (in shares)		8,741,863
Issuance of common stock upon exercise of warrants and other, net	172,519		172,519
Net cash contributions from follow-on offering (in shares)		17,000,000
Net cash contributions from follow-on offering	402,240	$ 2	402,238
Stock-based compensation	10,945		10,945
Other comprehensive loss	0
Net income (loss)	(53,592)				(53,592)
Shares, ending balance (in shares) at Mar. 31, 2021		395,807,813
Ending balance at Mar. 31, 2021	588,911	$ 39	880,779	0	(291,907)
Shares, beginning balance (in shares) at Dec. 31, 2021		408,753,837
Beginning balance at Dec. 31, 2021	$ 623,700	$ 40	1,043,600	(248)	(419,692)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and release of restricted stock units (in shares)	774,983	879,936
Issuance of common stock upon exercise of stock options and release of restricted stock units	$ 236		236
Stock-based compensation	77,925		77,925
Other comprehensive loss	(2,046)			(2,046)
Net income (loss)	(148,113)				(148,113)
Other, net	(64)		(64)
Shares, ending balance (in shares) at Mar. 31, 2022		409,633,773
Ending balance at Mar. 31, 2022	$ 551,638	$ 40	$ 1,121,697	$ (2,294)	$ (567,805)