Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2017	$ 0	$ 197,367	$ 1,227	$ (182,356)	$ 16,238
Balance (in shares) at Dec. 31, 2017	271,357
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ 0	0	0	(17,032)	(17,032)
Foreign currency translation adjustment	0	0	(4)	0	(4)
Stock-based compensation, net	$ 0	2,087	0	0	2,087
Stock-based compensation, net (in shares)	12
Issuance of unregistered shares	$ 0	0	0	0	0
Issuance of unregistered shares (in shares)	7,116
Issuance of common stock, net	$ 0	4,647	0	0	4,647
Issuance of common stock, net (in shares)	181,941
Conversion of preferred stock into common stock	$ 0	0	0	0	0
Conversion of preferred stock into common stock (in shares)	53,019
Balance at Dec. 31, 2018	$ 0	204,101	1,223	(199,388)	5,936
Balance (in shares) at Dec. 31, 2018	513,445
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ 0	0	0	(18,114)	(18,114)
Foreign currency translation adjustment	0	0	(9)	0	(9)
Stock-based compensation, net	$ 0	1,512	0	0	1,512
Stock-based compensation, net (in shares)	3
Issuance of common stock, net	$ 0	12,665	0	0	12,665
Issuance of common stock, net (in shares)	2,250,084
Conversion of preferred stock into common stock	$ 0	0	0	0	0
Conversion of preferred stock into common stock (in shares)	1,910,536
Balance at Dec. 31, 2019	$ 0	$ 218,278	$ 1,214	$ (217,502)	$ 1,990
Balance (in shares) at Dec. 31, 2019	4,674,068