Consolidated Statements of Changes in Equity (Parentheticals) - USD ($) $ in Thousands		12 Months Ended
	Aug. 07, 2019	Dec. 31, 2019	Dec. 31, 2018	Jan. 31, 2018	Jan. 17, 2018
Private Placement [Member] | Investor Warrants [Member]
Proceeds allocated to warrant liabilities			$ 1,890
Private Placement [Member] | Placement Agent Warrants [Member]
Proceeds allocated to warrant liabilities			385
Private Placement [Member]
Direct offering costs	$ 15	$ 15	1,194
Investor Warrants [Member]
Proceeds allocated to warrant liabilities		71	503	$ 1,890	$ 1,890
Placement Agent Warrants [Member]
Proceeds allocated to warrant liabilities		36	103	385	$ 385
Proceeds allocated to warrant liabilities		$ 107	$ 606	$ 2,275