Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock Employee [Member]	Common Stock Consultants[Member]	Common Stock	Additional Paid-in Capital Employee [Member]	Additional Paid-in Capital Consultants[Member]	Additional Paid-in Capital	Accumulated Deficit Employee [Member]	Accumulated Deficit Consultants[Member]	Accumulated Deficit	Accumulated Other Comprehensive Income Employee [Member]	Accumulated Other Comprehensive Income Consultants[Member]	Accumulated Other Comprehensive Income	Employee [Member]	Consultants[Member]	Total
Balance at Dec. 31, 2017			$ 103,045			$ 43,837			$ (121,368)			$ 1,243			$ 26,757
Balance (in shares) at Dec. 31, 2017			18,411
Short swing profit judgment offset with settlement expense			$ 0			18			0			0			18
Stock options issued	$ 0	$ 0		$ 1,825	$ 272		$ 0	$ 0		$ 0	$ 0		$ 1,825	$ 272
Exercise of stock options			$ 436			(226)			0			0			210
Exercise of stock options (in shares)	0		122
Exercise of warrants			$ 2,911			(792)			0			0			2,119
Exercise of warrants (in shares)			1,363
Net loss			$ 0			0			(9,888)			0			(9,888)
Balance at Dec. 31, 2018			$ 106,392			44,934			(131,256)			1,243			21,313
Balance (in shares) at Dec. 31, 2018			19,896
Stock options issued	$ 0	$ 0		$ 2,665	$ 417		$ 0	$ 0		$ 0	$ 0		$ 2,665	$ 417
Exercise of warrants (in shares)			0
Warrants issued to consultants			$ 0			255			0			0			255
Net loss			0			0			(12,775)			0			(12,775)
Balance at Dec. 31, 2019			$ 106,392			$ 48,271			$ (144,031)			$ 1,243			$ 11,875
Balance (in shares) at Dec. 31, 2019			19,896