Note 10 - Dividends Payable (Details Textual) - USD ($)	3 Months Ended
	Jun. 30, 2018	Aug. 01, 2018
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	$ 14,000
Preferred Stock, Dividend Rate, Percentage	5.00%
Series 3 Preferred Stock [Member]
Dividends, Preferred Stock, Total	$ 8,000
Preferred Stock, Dividend Rate, Percentage	5.00%
Series 2 Preferred Stock and Series 3 Preferred Stock [Member]
Dividends, Preferred Stock, Total	$ 520,000
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	45 days
Series 2 Preferred Stock and Series 3 Preferred Stock [Member] | Subsequent Event [Member]
Preferred Stock, Redemption Amount		$ 2,400,000