Note 9 - Preferred Stock (Details Textual) - USD ($)				12 Months Ended
	Nov. 27, 2018	May 17, 2018	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Debt Conversion, Converted Instrument, Amount					$ 4,250,000
Preferred Stock, Par or Stated Value Per Share				$ 0.001	$ 0.001
Stock Redeemed or Called During Period, Value				$ 4,250,000
Dividends Payable					$ 106,000
Series A Preferred Stock [Member]
Debt Conversion, Converted Instrument, Amount			$ 4,250,000
Debt Conversion, Converted Instrument, Shares Issued			4,250
Preferred Stock, Shares Outstanding, Ending Balance				0	4,250
Preferred Stock, Par or Stated Value Per Share					$ 1,000
Preferred Stock, Dividend Rate, Percentage					10.00%
Preferred Stock Redeemed or Called During Period, Percent		25.00%
Stock Redeemed or Called During Period, Shares	3,187	1,063
Stock Redeemed or Called During Period, Value	$ 3,187,000	$ 1,063,000
Dividends Payable				$ 0