Note 7 - Derivative Obligations - Fair Value Assumptions (Details) - Series A Warrant [Member]	Jun. 30, 2019	Dec. 31, 2018
Measurement Input, Share Price [Member]
Valuation assumption	2.81	2.7
Measurement Input, Price Volatility [Member]
Valuation assumption	0.93	0.94
Measurement Input, Expected Term [Member]
Valuation assumption	1.7	2.2
Measurement Input, Discount Rate [Member]
Valuation assumption	0.0181	0.0248
Measurement Input, Expected Dividend Rate [Member]
Valuation assumption	0	0
Measurement Input, Exercise Price [Member]
Valuation assumption	80	80