Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Treasury	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2018		13,854,205	50,467
Beginning balance at Dec. 31, 2018	$ 44,591	$ 14	$ 0	$ 90,664	$ (13)	$ (46,074)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Units in Private Placement, net of offering costs (in shares)		4,706,700
Issuance of Units in Private Placement, net of offering costs	23,618	$ 5		23,613
Exercise of stock options (in shares)		124
Exercise of stock options	0
Stock-based compensation	754			754
Unrealized gain on investments	15				15
Unrealized loss on foreign currency translation	(14)				(14)
Net loss	(12,381)					(12,381)
Ending balance (in shares) at Mar. 31, 2019		18,561,029	50,467
Ending balance at Mar. 31, 2019	56,583	$ 19	$ 0	115,031	(12)	(58,455)
Beginning balance (in shares) at Dec. 31, 2019		18,587,892	50,467
Beginning balance at Dec. 31, 2019	29,474	$ 19	$ 0	117,371	10	(87,926)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of warrants	60			60
Stock-based compensation	986			986
Unrealized gain on investments	(15)				(15)
Unrealized loss on foreign currency translation	(113)				(113)
Net loss	(5,533)					(5,533)
Ending balance (in shares) at Mar. 31, 2020		18,587,892	50,467
Ending balance at Mar. 31, 2020	$ 24,859	$ 19	$ 0	$ 118,417	$ (118)	$ (93,459)