Note 8 - Derivative Obligations (Details Textual) - USD ($)	6 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Jun. 30, 2017	Jun. 30, 2016
Class of Warrant or Right, Outstanding	4,828,723	17,265,208	4,828,723	4,828,723
Derivative, Gain (Loss) on Derivative, Net, Total	$ 133,000	$ 596,000	$ (60,000)
Series A Warrant [Member]
Class of Warrant or Right, Outstanding				404,412