Note 8 - Preferred Stock and Warrants (Details Textual) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Preferred Stock, Shares Outstanding	0	9,360
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
Series A Preferred Stock [Member]
Stock Redeemed or Called During Period, Shares	9,360	8,661	9,979
Preferred Stock, Redemption Price Per Share		$ 1,000	$ 1,000
Preferred Stock, Shares Outstanding	0