Note 15 - Subsequent Events (Details Textual) - USD ($)	Feb. 13, 2020	Mar. 17, 2020	Dec. 31, 2019	Dec. 31, 2018	May 15, 2017
Convertible Notes Payable, Total			$ 413,000
Short Term Investment Minimum					$ 2,000,000
The Note [Member]
Interest Payable			1,869,000
Convertible Notes Payable, Total			$ 1,131,000
Subsequent Event [Member]
Short Term Investment Minimum		$ 1,000,000
Subsequent Event [Member] | The Note [Member]
Convertible Notes Payable, Total	$ 7,582,000
Conversion of Convertible Promissory Note into Common Stock [Member] | Subsequent Event [Member]
Debt Conversion, Original Debt, Amount	$ 3,000,000
Debt Conversion, Converted Instrument, Shares Issued	1,666,670
Debt Conversion, Converted Instrument, Price Per Share	$ 1.80