Consolidated Statements of Changes in Shareholders' (Deficit) Equity - USD ($) $ in Thousands	Stock Units Issued (SUI) [Member] Preferred Stock [Member]	Stock Units Issued (SUI) [Member] Common Stock [Member]	Stock Units Issued (SUI) [Member] Retained Earnings [Member]	Stock Units Issued (SUI) [Member]	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2021					150	5,158,967
Balance at Dec. 31, 2021					$ 75	$ 326,279	$ (307,859)	$ 18,495
Sales of common stock and common stock warrants, net of costs (in shares)					0	675,000
Sales of common stock and common stock warrants, net of costs					$ 0	$ 986	0	986
Common stock awards under equity incentive plans (in shares)					0	137,695
Common stock awards under equity incentive plans					$ 0	$ 1,261		1,261
Exercise of common stock warrant (in shares)					0	325,000
Exercise of common stock warrant					$ 0	$ 0	0	0
Common stock issued to vendors (in shares)	0	0			0	2,400
Common stock issued to vendors	$ 0	$ 15	$ 0	$ 15	$ 0	$ 10	0	10
Other (in shares)					0	10,447
Net loss					$ 0	$ 0	(7,858)	(7,858)
Balance (in shares) at Dec. 31, 2022					150	6,309,509
Balance at Dec. 31, 2022					$ 75	$ 328,551	(315,717)	12,909
Sales of common stock and common stock warrants, net of costs (in shares)					0	2,851,032
Sales of common stock and common stock warrants, net of costs					$ 0	$ 1,155	0	1,155
Common stock awards under equity incentive plans (in shares)					0	290,935
Common stock awards under equity incentive plans					$ 0	$ 412		412
Common stock issued to vendors (in shares)	0	59,465			0	2,400
Common stock issued to vendors	$ 0	$ 4	$ 0	$ 4	$ 0	$ 80	0	80
Net loss					$ 0	$ 0	(17,560)	(17,560)
Balance (in shares) at Dec. 31, 2023					150	9,513,341
Balance at Dec. 31, 2023					$ 75	$ 330,202	$ (333,277)	$ (3,000)