Note 1 - Nature of the Business and Basis of Preparation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands |
6 Months Ended | ||
|---|---|---|---|
Mar. 14, 2017 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Shares Issued, Price Per Share | $ 20 | ||
| Proceeds from Issuance of Common Stock | $ 50,505 | ||
| IPO [Member] | |||
| Shares Issued, Price Per Share | $ 20 | ||
| Stock Issued During Period, Shares, New Issues | 174,286 | ||
| Proceeds from Issuance of Common Stock | $ 47,184 | ||
| Private Placement [Member] | |||
| Stock Issued During Period, Shares, New Issues | 2,541,048 | ||
| Private Placement [Member] | Nereus Trust [Member] | |||
| Stock Issued in Lieu of Royalty Payments | 2,112,963 | ||