Note 6 - Derivative Obligations - Fair Value Assumptions (Details) - Series A Warrant [Member]	Jun. 30, 2018	Dec. 31, 2017
Measurement Input, Share Price [Member]
Valuation assumption	0.42	3
Measurement Input, Price Volatility [Member]
Valuation assumption	1.112	1.07
Measurement Input, Expected Term [Member]
Valuation assumption	2.7	3.2
Measurement Input, Discount Rate [Member]
Valuation assumption	0.026	0.0199
Measurement Input, Expected Dividend Rate [Member]
Valuation assumption	0	0
Measurement Input, Exercise Price [Member]
Valuation assumption	8	8