Note 12 - Quarterly Financial Information (Unaudited, in Thousands, Except Share and Per Share Data) (Details Textual) - USD ($)		1 Months Ended		3 Months Ended	12 Months Ended
	Oct. 27, 2014	Oct. 31, 2014	Oct. 27, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
IPO [Member]
Proceeds from Issuance Initial Public Offering	$ 62,500,000	$ 62,500,000
Stock Issued During Period, Shares, New Issues	7,026,500	7,026,500
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		916,500
Conversion of Stock, Shares Issued			8,651,805
Warrant [Member]
Proceeds from Issuance or Sale of Equity			$ 1,400,000
Preferred Stock, Accretion of Redemption Discount				$ 1,300,000
Proceeds from Issuance Initial Public Offering						$ 62,485,000
Stock Issued During Period, Shares, Warrants Exercised			498,889