CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock
Beginning balance at Dec. 31, 2019	$ 28,497	$ 23	$ 156,727	$ (126,912)	$ (1,341)
Increase (Decrease) in Stockholders' Equity
Net loss	(22,982)			(22,982)
Stock-based compensation expense	607		535		72
Common stock issued for stock-based awards, net	(25)				(25)
Ending balance at Dec. 31, 2020	6,097	23	157,262	(149,894)	(1,294)
Increase (Decrease) in Stockholders' Equity
Net loss	(48,472)			(48,472)
Stock-based compensation expense	394		174		220
Common stock issued for stock-based awards, net	(42)				(42)
Ending balance at Dec. 31, 2021	$ (42,023)	$ 23	$ 157,436	$ (198,366)	$ (1,116)