CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Previously Reported Common Stock	Previously Reported Additional Paid-in Capital	Cumulative Effect Adjustment	Common Stock LPC Program [Member]	Common Stock Registered direct purchase agreement	Common Stock Subscription Agreement	Common Stock Private Placement	Common Stock Firm Commitment Offering	Common Stock	Additional Paid-in Capital LPC Program [Member]	Additional Paid-in Capital Registered direct purchase agreement	Additional Paid-in Capital Subscription Agreement	Additional Paid-in Capital Private Placement	Additional Paid-in Capital Firm Commitment Offering	Additional Paid-in Capital	Accumulated Deficit Subscription Agreement	Accumulated Deficit	LPC Program [Member]	Registered direct purchase agreement	Subscription Agreement	Private Placement	Firm Commitment Offering	Total
Increase (Decrease) in Stockholders' Equity
Adjustment related to correction of immaterial error (Note 3)			$ (113)														$ (113)
Adjusted balance at End of period									$ 955						$ 517,806		(511,391)						$ 7,370
Balance at Dec. 31, 2018	$ 955	$ 517,806															(511,278)						7,483
Balance (in shares) at Dec. 31, 2018	95,620,796								95,620,796
Increase (Decrease) in Stockholders' Equity
Stock compensation accrued and shares issued for vested stock awards (Note 16)									$ 3						556								559
Stock compensation accrued and shares issued for vested stock awards (Note 16)(in shares)									312,000
Modification of previously awarded KELTIP Units (Note 16)															583								583
Shares issued under the at-the-market offering agreement, net (Note 16)									$ 1						11								12
Shares issued under the at-the-market offering agreement, net (Note 16)(in shares)									33,995
Shares issued under the at-the-market offering agreement, net (Note 16)				$ 21						$ 507								$ 528
Shares issued under the Lincoln Park commitment purchase agreement, net (Note 16)(in shares)				2,113,642
Stock Issued During Period, Value, New Issues					$ 87						$ 1,848								$ 1,935
Stock Issued During Period, Shares, New Issues					8,653,846													2,113,642
Deemed dividend on warrants (Note 4)															3		(3)
Net loss																	(5,386)						(5,386)
Balance at Dec. 31, 2019									$ 1,067						521,314		(516,780)						5,601
Balance (in shares) at Dec. 31, 2019									106,734,279
Increase (Decrease) in Stockholders' Equity
Stock compensation accrued and shares issued for vested stock awards (Note 16)									$ 3						856								859
Stock compensation accrued and shares issued for vested stock awards (Note 16)(in shares)									300,000
Shares issued under the at-the-market offering agreement, net (Note 16)									$ 9						214								223
Shares issued under the at-the-market offering agreement, net (Note 16)(in shares)									823,452
Shares issued under the at-the-market offering agreement, net (Note 16)				$ 9						$ 207								$ 216
Shares issued under the Lincoln Park commitment purchase agreement, net (Note 16)(in shares)				900,000
Stock Issued During Period, Value, New Issues						$ 47	$ 150	$ 205				$ 898	$ 2,561	$ 7,748						$ 945	$ 2,711	$ 7,953
Stock Issued During Period, Shares, New Issues						4,719,207	15,000,000	20,535,714										900,000
Warrants exercised									$ 85						2,465								2,550
Warrants exercised (in shares)									8,500,000
Net loss																	(9,086)						(9,086)
Balance at Dec. 31, 2020									$ 1,575						$ 536,263		$ (525,866)						$ 11,972
Balance (in shares) at Dec. 31, 2020									157,512,652