Note 8 - Preferred Stock and Warrants (Details Textual) - $ / shares	12 Months Ended
	Dec. 31, 2015	Jun. 30, 2016
Series A Preferred Stock [Member]
Preferred Stock, Shares Issued		18,021
Stock Redeemed or Called During Period, Shares	9,979
Preferred Stock, Redemption Price Per Share	$ 1,000
Preferred Stock, Shares Issued	18,021	18,021
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		500,000
Preferred Stock, Liquidation Preference Per Share		$ 1,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 8.40