Note 8 - Derivative Obligations - Fair Value Assumptions (Details) - Series A Warrant [Member]	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2017
Measurement Input, Share Price [Member]
Valuation assumption	0.27	3	3.17
Measurement Input, Price Volatility [Member]
Valuation assumption	0.94	1.07	1.1
Measurement Input, Expected Term [Member]
Valuation assumption	2.2	3.2	3.7
Measurement Input, Discount Rate [Member]
Valuation assumption	0.0248	0.0199	0.0166
Measurement Input, Expected Dividend Rate [Member]
Valuation assumption	0	0	0
Measurement Input, Exercise Price [Member]
Valuation assumption	8	8	8