Condensed Consolidated Statements Of Convertible Redeemable Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Series H Preferred Stock [Member]	Series J Convertible Preferred Stock [Member]	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Mezzanine Equity Series H Preferred Stock [Member]	Mezzanine Equity Series J Convertible Preferred Stock [Member]
Beginning balance at Dec. 31, 2022	$ 4,889			$ 0	$ 301,790	$ (733)	$ (296,168)
Balance (in shares) at Dec. 31, 2022				77,000
Sale of common stock and pre-funded warrants, net of fees	8,503			$ 0	8,503
Sale of common stock and pre-funded warrants, net of fees ,shares				172,000
Deemed dividend on Series F Convertible Preferred Stock	0
Stock-based compensation	521				521
Exercise of common stock warrants	14			$ 0	14
Exercise of common stock warrants, shares				14,000
Net loss	(5,849)						(5,849)
Foreign currency translation adjustments	80					80
Ending balance at Mar. 31, 2023				$ 0	310,828	(653)	(302,017)
Ending Balance at Mar. 31, 2023	8,158
Ending Balance (in shares) at Mar. 31, 2023				263,000
Beginning balance at Dec. 31, 2023	(247)			$ 3	317,103	(553)	(316,800)	$ 346	$ 1,857
Beginning balance at Dec. 31, 2023	$ 2,203
Beginning balance, shares at Dec. 31, 2023		5,000	15,000					5,000	15,000
Balance (in shares) at Dec. 31, 2023	3,416,000			3,416,000
Paid-in-kind dividend on Series J Convertible Redeemable Preferred Stock, Shares									1,000
Sale of common stock and pre-funded warrants, net of fees	$ 2,784			$ 8	2,776
Sale of common stock and pre-funded warrants, net of fees ,shares				7,795,000
Exercise of Class A Warrants, Shares				13,063,000
Exercise of Class A Warrants	1,989			$ 13	1,976
Deemed dividend on Series F Convertible Preferred Stock	0
Stock-based compensation	102				102
Issuance of stock from RSUs, net, shares				4,000
Exercise of common stock warrants	9			$ 9	0
Exercise of common stock warrants, shares				8,979,000
Net loss	(6,485)						(6,485)
Foreign currency translation adjustments	(86)					(86)
Ending balance at Mar. 31, 2024	(1,934)			$ 33	$ 321,957	$ (639)	$ (323,285)	$ 346	$ 1,857
Ending Balance at Mar. 31, 2024	$ 2,203
Ending Balance (in shares) at Mar. 31, 2024	33,257,000			33,257,000
Ending balance, shares at Mar. 31, 2024		5,000	16,000					5,000	16,000