Note 2 - Liquidity (Details Textual) - USD ($)			1 Months Ended	6 Months Ended	10 Months Ended
	May 01, 2017	Mar. 31, 2017	Mar. 31, 2017	Jun. 30, 2017	Jan. 07, 2018
Class of Warrant or Right, Term				4 years 273 days
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 2.22
Series A Preferred Stock [Member] | Private Placement [Member]
Private Placement Proceeds, Gross			$ 25,000,000
Number of Convertible Preferred Stock Per Unit		1	1
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right		1	1
Temporary Equity, Stock Issued During Period, New Issues			12,376,329
Private Placement Proceeds, Net			$ 22,100,000
Payments of Stock Issuance Costs			$ 2,900,000		$ 2,900,000
Class of Warrant or Right, Granted During Period			1,179,558
Series B Preferred Stock [Member]
Preferred Stock, Intended Par or Stated Value Per Share	$ 0.001
Preferred Stock, Intended Offering Price Per Share	$ 2.10
Number of Convertible Preferred Stock Per Unit	1
Class of Warrant or Right, Term	5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right	1
Maximum Preferred Stock Intended to Be Offered, Value	$ 20,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 2.31