CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Series B Preferred Stock	At-the-market Issuance	Registered Direct Offering	Subscription Agreements and Warrant Exercises	Preferred Stock Series A Preferred Stock	Preferred Stock Series B Preferred Stock	Common Stock	Common Stock At-the-market Issuance	Common Stock Registered Direct Offering	Common Stock Subscription Agreements and Warrant Exercises	Treasury Stock	Additional Paid-in Capital	Additional Paid-in Capital Series B Preferred Stock	Additional Paid-in Capital At-the-market Issuance	Additional Paid-in Capital Registered Direct Offering	Additional Paid-in Capital Subscription Agreements and Warrant Exercises	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019						7	0	52,746,728
Beginning balance at Dec. 31, 2019	$ 11,019					$ 0	$ 0	$ 528				$ (48)	$ 62,019					$ (51,480)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	222												222
Net loss	(3,944)																	(3,944)
Ending balance (in shares) at Mar. 31, 2020						7	0	52,746,728
Ending balance at Mar. 31, 2020	7,297					$ 0	$ 0	$ 528				(48)	62,241					(55,424)
Beginning balance (in shares) at Dec. 31, 2019						7	0	52,746,728
Beginning balance at Dec. 31, 2019	11,019					$ 0	$ 0	$ 528				(48)	62,019					(51,480)
Increase (Decrease) in Stockholders' Equity
Net loss	(18,032)
Ending balance (in shares) at Sep. 30, 2020						7	0	162,147,973
Ending balance at Sep. 30, 2020	14,421					$ 0	$ 0	$ 1,621				(48)	82,360					(69,512)
Beginning balance (in shares) at Mar. 31, 2020						7	0	52,746,728
Beginning balance at Mar. 31, 2020	7,297					$ 0	$ 0	$ 528				(48)	62,241					(55,424)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	149												149
Issuance of stock (in shares)									59,132,191		1,328,405
Issuance of stock			$ 15,437		$ 332				$ 591		$ 13				$ 14,846		$ 319
Warrant Exchange (in shares)								21,920,820
Warrant Exchange	(4,978)							$ 219					(5,197)
Net loss	(3,614)																	(3,614)
Ending balance (in shares) at Jun. 30, 2020						7	0	135,128,144
Ending balance at Jun. 30, 2020	14,623					$ 0	$ 0	$ 1,351				(48)	72,358					(59,038)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	126												126
Issuance of stock (in shares)									27,019,829
Issuance of stock			10,146						$ 270						9,876
Net loss	(10,474)																	(10,474)
Ending balance (in shares) at Sep. 30, 2020						7	0	162,147,973
Ending balance at Sep. 30, 2020	14,421					$ 0	$ 0	$ 1,621				(48)	82,360					(69,512)
Beginning balance (in shares) at Dec. 31, 2020						7	0	184,133,384
Beginning balance at Dec. 31, 2020	21,550					$ 0	$ 0	$ 1,841				(48)	93,059					(73,302)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	833												833
Issuance of common stock for option exercises (in shares)								157,468
Issuance of common stock for option exercises	176							$ 2					174
Issuance of stock (in shares)							54,745		987,000	3,000,000
Issuance of stock		$ 4,954	$ 4,849	$ 21,204			$ 1		$ 10	$ 30				$ 4,953	$ 4,839	$ 21,174
Net loss	(7,077)																	(7,077)
Ending balance (in shares) at Mar. 31, 2021						7	54,745	188,277,852
Ending balance at Mar. 31, 2021	46,489					$ 0	$ 1	$ 1,883				(48)	125,032					(80,379)
Beginning balance (in shares) at Dec. 31, 2020						7	0	184,133,384
Beginning balance at Dec. 31, 2020	$ 21,550					$ 0	$ 0	$ 1,841				(48)	93,059					(73,302)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock for option exercises (in shares)	901,250
Net loss	$ (43,784)
Ending balance (in shares) at Sep. 30, 2021						7	54,745	199,049,329
Ending balance at Sep. 30, 2021	107,110					$ 0	$ 1	$ 1,990				(48)	222,253					(117,086)
Beginning balance (in shares) at Mar. 31, 2021						7	54,745	188,277,852
Beginning balance at Mar. 31, 2021	46,489					$ 0	$ 1	$ 1,883				(48)	125,032					(80,379)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	2,095												2,095
Issuance of stock (in shares)										10,000,000
Issuance of stock				$ 93,406						$ 100						$ 93,306
Issuance of common stock for option and warrant exercises (in shares)								538,893
Issuance of common stock for option and warrant exercises	371							$ 5					366
Net loss	(25,952)																	(25,952)
Ending balance (in shares) at Jun. 30, 2021						7	54,745	198,816,745
Ending balance at Jun. 30, 2021	116,409					$ 0	$ 1	$ 1,988				(48)	220,799					(106,331)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	1,347												1,347
Issuance of common stock for option exercises (in shares)								232,584
Issuance of common stock for option exercises	109							$ 2					107
Net loss	(10,755)																	(10,755)
Ending balance (in shares) at Sep. 30, 2021						7	54,745	199,049,329
Ending balance at Sep. 30, 2021	$ 107,110					$ 0	$ 1	$ 1,990				$ (48)	$ 222,253					$ (117,086)