Note 2 - Summary of Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands			6 Months Ended
	Oct. 27, 2014 USD ($) $ / shares shares	Oct. 06, 2014	Jun. 30, 2015 USD ($) shares	Jun. 30, 2014 USD ($)
IPO [Member] | Underwriters [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	916,500
IPO [Member]
Stock Issued During Period, Shares, New Issues	7,026,500
Share Price | $ / shares	$ 10
Proceeds from Issuance Initial Public Offering | $	$ 62,500
Payments of Stock Issuance Costs | $	$ 7,800
Conversion of Stock, Shares Converted	8,651,805
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio		15.87
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			4,158
Payments of Stock Issuance Costs | $				$ 437