Condensed Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series A 12% convertible preferred stock	Series C super dividend redeemable convertible preferred stock dividend	Series A 12% convertible preferred stock	Common Stock [Member]	Common Stock [Member] Series A 12% convertible preferred stock	Common Stock [Member] Series C super dividend redeemable convertible preferred stock dividend	Additional Paid-In Capital	Additional Paid-In Capital Series A 12% convertible preferred stock	Additional Paid-In Capital Series C super dividend redeemable convertible preferred stock dividend	Retained Deficit	Retained Deficit Series A 12% convertible preferred stock	Retained Deficit Series C super dividend redeemable convertible preferred stock dividend
Stockholders' Equity, Balance (in shares) at Dec. 31, 2019				1,327,500	56,894,642
Stockholders' Equity, Balance at Dec. 31, 2019	$ 43,872			$ 537	$ 56			$ 259,673			$ (216,394)
Temporary Equity, Balance (in shares) at Dec. 31, 2019			176
Temporary Equity, Balance at Dec. 31, 2019			$ 1,723
Convertible preferred stock dividend			$ (1)						$ 26	$ 34		$ (26)	$ (35)
Convertible preferred stock dividend (in shares)						13,275	17,600
Issuance of common stock	44							44
Issuance of common stock (in shares)					14,452
Issuance of common stock for exercise of warrants and options	219							219
Issuance of common stock for exercise of warrants and options (in shares)					84,624
Stock-based compensation on expense	824							824
Stock-based compensation on expense (in shares)					19,068
Net loss	(9,670)										(9,670)
Temporary Equity, Balance (in shares) at Jun. 30, 2020			176
Temporary Equity, Balance at Jun. 30, 2020			$ 1,723
Stockholders' Equity, Balance (in shares) at Jun. 30, 2020				1,327,500	57,043,661
Stockholders' Equity, Balance at Jun. 30, 2020	35,288			$ 537	$ 56			260,820			(226,125)
Stockholders' Equity, Balance (in shares) at Mar. 31, 2020				1,327,500	57,029,209
Stockholders' Equity, Balance at Mar. 31, 2020	41,030			$ 537	$ 56			260,382			(219,945)
Convertible preferred stock dividend		$ (40)	$ (26)									(40)	(26)
Issuance of common stock	44				$ 14,452			44
Stock-based compensation on expense	394							394
Net loss	(6,114)										(6,114)
Temporary Equity, Balance (in shares) at Jun. 30, 2020			176
Temporary Equity, Balance at Jun. 30, 2020			$ 1,723
Stockholders' Equity, Balance (in shares) at Jun. 30, 2020				1,327,500	57,043,661
Stockholders' Equity, Balance at Jun. 30, 2020	35,288			$ 537	$ 56			260,820			(226,125)
Stockholders' Equity, Balance (in shares) at Dec. 31, 2020				1,302,500	57,077,055
Stockholders' Equity, Balance at Dec. 31, 2020	22,470			$ 527	$ 56			261,883			(239,996)
Temporary Equity, Balance (in shares) at Dec. 31, 2020			176
Temporary Equity, Balance at Dec. 31, 2020			$ 1,723
Convertible preferred stock dividend									$ 28	$ 39		(28)	(39)
Convertible preferred stock dividend (in shares)						13,025	17,600
Issuance of common stock	3,864				$ 1			3,863
Issuance of common stock (in shares)					845,214
Issuance of common stock for exercise of warrants and options	2,951				$ 2			2,949
Issuance of common stock for exercise of warrants and options (in shares)					1,289,444
Stock-based compensation on expense	895							895
Stock-based compensation on expense (in shares)					32,693
Net loss	(14,787)										(14,787)
Temporary Equity, Balance (in shares) at Jun. 30, 2021			176
Temporary Equity, Balance at Jun. 30, 2021			$ 1,723
Stockholders' Equity, Balance (in shares) at Jun. 30, 2021				1,302,500	59,275,031
Stockholders' Equity, Balance at Jun. 30, 2021	15,393			$ 527	$ 59			269,657			(254,850)
Stockholders' Equity, Balance (in shares) at Mar. 31, 2021				1,302,500	57,186,655
Stockholders' Equity, Balance at Mar. 31, 2021	16,511			$ 527	$ 56			262,264			(246,336)
Convertible preferred stock dividend		$ (38)	$ (27)									$ (38)	$ (27)
Issuance of common stock	3,864				$ 1			3,863
Issuance of common stock (in shares)					845,214
Issuance of common stock for exercise of warrants and options	2,951				$ 2			2,949
Issuance of common stock for exercise of warrants and options (in shares)					1,243,162
Stock-based compensation on expense	581							581
Net loss	(8,449)										(8,449)
Temporary Equity, Balance (in shares) at Jun. 30, 2021			176
Temporary Equity, Balance at Jun. 30, 2021			$ 1,723
Stockholders' Equity, Balance (in shares) at Jun. 30, 2021				1,302,500	59,275,031
Stockholders' Equity, Balance at Jun. 30, 2021	$ 15,393			$ 527	$ 59			$ 269,657			$ (254,850)