Note 19 - Unaudited Quarterly Financial Data - Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Total revenue | $ 740 | $ 1,487 | $ 2,659 | $ 3,109 | $ 6,435 | $ 3,366 | $ 4,531 | $ 3,025 | $ 7,995 | $ 17,357 | $ 19,263 |
| Total operating costs and expenses | 8,547 | 10,348 | 12,600 | 15,182 | 13,573 | 11,341 | 12,853 | 11,547 | 46,677 | 49,314 | 39,217 |
| Net income / (loss) | $ (9,885) | $ (13,013) | $ (13,059) | $ (15,551) | $ (9,682) | $ (11,402) | $ (11,092) | $ (10,981) | $ (51,508) | $ (43,157) | $ (24,399) |
| Net income / (loss) per share (basic) (in dollars per share) | $ (0.20) | $ (0.28) | $ (0.29) | $ (0.34) | $ (0.21) | $ (0.25) | $ (0.24) | $ (0.24) | $ (1.10) | $ (0.95) | $ (0.55) |
| Net income / (loss) per share (diluted) (in dollars per share) | $ (0.20) | $ (0.28) | $ (0.29) | $ (0.34) | $ (0.21) | $ (0.25) | $ (0.24) | $ (0.25) | $ (1.10) | $ (0.95) | $ (0.60) |