Note 7 - Embedded Derivatives - Schedule of Inputs to Lattice Model Used to Value Embedded Derivatives (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares	Dec. 31, 2017 $ / shares shares
Stock price (in dollars per share)	$ 1.96	$ 11.80
Conversion Rate (in shares) | shares	67.95	1,358.9
Conversion Price (in dollars per share)	$ 14.72	$ 14.72
Maturity date	Mar. 15, 2020	Mar. 15, 2020
Measurement Input, Risk Free Interest Rate [Member]
Risk-free interest rate	0.0257	0.000189
Measurement Input, Price Volatility [Member]
Risk-free interest rate	1.5	0.0075
Measurement Input, Entity Credit Risk [Member]
Risk-free interest rate	0.31	0.0028