Note 2 - Liquidity (Details Textual) - USD ($)		1 Months Ended	9 Months Ended		10 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Jan. 07, 2018
Proceeds from Issuance of Convertible Preferred Stock, Net of Offering Costs			$ 22,129,774
Series A Preferred Stock [Member]
Proceeds from Issuance of Private Placement			$ 0
Series A Preferred Stock [Member] | Private Placement [Member]
Proceeds from Issuance of Private Placement		$ 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
Proceeds from Issuance of Convertible Preferred Stock, Net of Offering Costs		$ 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