CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Previously Reported Common Stock	Previously Reported Additional Paid-in Capital	Previously Reported Accumulated Deficit	Previously Reported Accumulated Other Comprehensive Income (loss)	Previously Reported	Cumulative Effect Adjustment Accumulated Deficit	Cumulative Effect Adjustment	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (loss)	LPC Program	Registered direct purchase agreement	Total
Increase (Decrease) in Stockholders' Equity
Cumulative adjustment related to change in accounting principle										$ (89)	$ 40			$ (49)
Adjusted balance at beginning of period								$ 919	$ 516,284	(509,325)				7,878
Balance at Dec. 31, 2017	$ 919	$ 516,284	$ (509,082)	$ (40)	$ 8,081	$ (154)	$ (154)
Balance (in shares) at Dec. 31, 2017	91,929,709							91,929,709
Increase (Decrease) in Stockholders' Equity
Stock compensation accrued and shares issued for vested stock awards								$ 4	312					316
Stock compensation accrued and shares issued for vested stock awards (in shares)								537,279
Registered direct purchase agreement, net								$ 32	1,202					1,234
Registered direct purchase agreement, net (in shares)								3,153,808					0
Deemed dividend on warrants									8	(8)
Net loss										(1,945)				(1,945)
Balance at Dec. 31, 2018	$ 955	$ 517,806	$ (511,278)		$ 7,483	$ (113)	$ (113)							7,370
Balance (in shares) at Dec. 31, 2018	95,620,796							95,620,796
Increase (Decrease) in Stockholders' Equity
Adjusted balance at beginning of period								$ 955	517,806	(511,391)				7,370
Stock compensation accrued and shares issued for vested stock awards								$ 3	556					559
Stock compensation accrued and shares issued for vested stock awards (in shares)								312,000
Modification of previously awarded KELTIP Units									583					583
Shares issued under the at-the-market offering agreement, net								$ 1	11					12
Shares issued under the at-the-market offering agreement, net (in shares)								33,995
Shares issued under the Lincoln Park commitment purchase agreement, net								$ 21	507					528
Shares issued under the Lincoln Park commitment purchase agreement, net (in shares)								2,113,642
Registered direct purchase agreement, net								$ 87	1,848					1,935
Registered direct purchase agreement, net (in shares)								8,653,846				2,113,642
Deemed dividend on warrants									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