Condensed Consolidated Statements of Stockholders Deficit - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (shares) at Dec. 31, 2018		39,053,312
Beginning balance at Dec. 31, 2018	$ (13,124)	$ 39	$ 308,018	$ 32	$ (321,213)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(11,626)				(11,626)
Share-based compensation	314		314
Common stock sales (in shares)		7,074,597
Common stock issued	7,500	$ 7	7,493
Equity instrument exercises (in shares)		2,250
Equity instrument exercises	4		4
Other	33			33
Ending balance (shares) at Jun. 30, 2019		46,130,159
Ending balance at Jun. 30, 2019	(16,899)	$ 46	315,829	65	(332,839)
Beginning balance (shares) at Mar. 31, 2019		40,722,229
Beginning balance at Mar. 31, 2019	(19,468)	$ 41	310,618	(62)	(330,065)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(2,774)				(2,774)
Share-based compensation	216		216
Common stock sales (in shares)		5,407,930
Common stock issued	5,000	$ 5	4,995
Other	127			127
Ending balance (shares) at Jun. 30, 2019		46,130,159
Ending balance at Jun. 30, 2019	$ (16,899)	$ 46	315,829	65	(332,839)
Beginning balance (shares) at Dec. 31, 2019	51,055,159	51,055,159
Beginning balance at Dec. 31, 2019	$ (27,728)	$ 51	319,275	(227)	(346,827)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(12,239)				(12,239)
Share-based compensation	93		93
Common stock sales (in shares)		48,298,893
Common stock issued	32,030	$ 48	31,982
Equity instrument exercises (in shares)		54,864
Equity instrument exercises	67		67
Other	$ 338			338
Ending balance (shares) at Jun. 30, 2020	99,408,916	99,408,916
Ending balance at Jun. 30, 2020	$ (7,439)	$ 99	351,417	111	(359,066)
Beginning balance (shares) at Mar. 31, 2020		66,133,888
Beginning balance at Mar. 31, 2020	(25,271)	$ 66	323,958	(45)	(349,250)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(9,816)				(9,816)
Share-based compensation	47		47
Common stock sales (in shares)		33,220,164
Common stock issued	27,378	$ 33	27,345
Equity instrument exercises (in shares)		54,864
Equity instrument exercises	67		67
Other	$ 156			156
Ending balance (shares) at Jun. 30, 2020	99,408,916	99,408,916
Ending balance at Jun. 30, 2020	$ (7,439)	$ 99	$ 351,417	$ 111	$ (359,066)