Statements of Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Receivables from Stockholder [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Beginning balance, value at Dec. 31, 2018	$ 100	$ 550,133			$ (546,116)	$ 4,117
Common Stock, Shares, Outstanding, Beginning Balance at Dec. 31, 2018	100,105
Share-based compensation expense	$ 1	1,613				1,614
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture	822
Sales of common stock, net of issuance costs	$ 25	16,750				16,775
Net loss					(26,483)	(26,483)
Ending balance, value at Dec. 31, 2019	126	568,496			(572,599)	(3,977)
Share-based compensation expense		1,252				1,252
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture	201
Sales of common stock, net of issuance costs	$ 26	30,477	(6,135)			24,368
Stock Issued During Period, Shares, New Issues	26,229
Net loss					(13,634)	(13,634)
Exercise of options	$ 1	999				$ 1,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	693
Common Stock, Shares, Outstanding, Ending Balance at Dec. 31, 2020	152,926					152,926
Ending balance, value at Dec. 31, 2020	$ 153	601,224	(6,135)		(586,233)	$ 9,009
Share-based compensation expense	$ 2	15,282				15,284
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture	2,365
Sales of common stock, net of issuance costs	$ 7	122,884	6,135			129,026
Stock Issued During Period, Shares, New Issues	7,554
Net loss					(43,200)	(43,200)
Exercise of options	$ 2	2,652				2,654
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	1,518
Other comprehensive loss				(19)		$ (19)
Common Stock, Shares, Outstanding, Ending Balance at Dec. 31, 2021	164,363					164,363
Ending balance, value at Dec. 31, 2021	$ 164	742,042		(19)	(629,433)	$ 112,754
Common Stock, Shares, Outstanding, Beginning Balance at Sep. 30, 2021	125,803
Net loss						$ (12,625)
Common Stock, Shares, Outstanding, Ending Balance at Dec. 31, 2021	164,363					164,363
Ending balance, value at Dec. 31, 2021	$ 164	$ 742,042		$ (19)	$ (629,433)	$ 112,754