Note 9 - Dividends Payable (Details Textual)	3 Months Ended
	Mar. 31, 2020 USD ($)
Series 1 Preferred Stock [Member]
Dividends, Preferred Stock, Total	$ 13,000
Preferred Stock, Dividend Rate, Percentage	5.00%
Series 2 Preferred Stock [Member]
Dividends, Preferred Stock, Total	$ 13,000
Preferred Stock, Dividend Rate, Percentage	5.00%
Series 3 Preferred Stock [Member]
Dividends, Preferred Stock, Total	$ 7,000
Preferred Stock, Dividend Rate, Percentage	5.00%
Series 2 Preferred Stock and Series 3 Preferred Stock [Member]
Dividends, Preferred Stock, Total	$ 33,000
Preferred Stock Unpaid Dividends Additional Late Fee Penalty Percentage	18.00%
Period From Issuance of Written Notice For Failure to Pay Dividend Within Which Entity Must Cure Breach (Day)	45 days
Preferred Stock, Redemption Amount	$ 1.70