Note 1 - Organization and Nature of Operations (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jan. 17, 2018	Dec. 31, 2018
Investor Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	645,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 6.60
Class of Warrant or Right, Term	2 years 180 days
Placement Agent Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	129,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 6.60
Class of Warrant or Right, Term	3 years
Private Placement [Member]
Stock Issued During Period, Shares, New Issues	2,150,001
Shares Issued, Price Per Share	$ 5.15
Proceeds from Issuance or Sale of Equity, Total	$ 11,100	$ 11,073