Note 6 - Derivative Obligations - Fair Value Assumptions (Details) - Series A Warrant [Member]	Mar. 31, 2018	Dec. 31, 2017
Measurement Input, Share Price [Member]
Valuation assumption	2.01	3
Measurement Input, Price Volatility [Member]
Valuation assumption	111	107
Measurement Input, Expected Term [Member]
Valuation assumption	2.9	3.2
Measurement Input, Discount Rate [Member]
Valuation assumption	2.38	1.99
Measurement Input, Expected Dividend Rate [Member]
Valuation assumption	0	0
Measurement Input, Exercise Price [Member]
Valuation assumption	8	8