Annual report pursuant to Section 13 and 15(d)

Quarterly Financial Data (Unaudited) (Details)

v3.8.0.1
Quarterly Financial Data (Unaudited) (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
Quarterly Financial Information [Line Items]                      
Total revenue $ 58 $ 40 $ 77 $ 40 $ 35 $ 26 $ 15,004 $ 0 $ 215 $ 15,065 $ 1,671
Net loss $ (3,660) $ (4,191) $ (3,451) $ (3,005) $ (2,327) $ (2,620) $ 11,928 $ (1,846) $ (14,307) $ 5,135 $ (11,279)
Basic net income (loss) per share $ (0.17) $ (0.20) $ (0.16) $ (0.14) $ (0.11) $ (0.12) $ 0.58 $ (0.09) $ (0.67) $ 0.25 $ (0.56)
Diluted net income (loss) per share $ (0.17) $ (0.20) $ (0.17) $ (0.16) $ (0.15) $ (0.12) $ 0.55 $ (0.09) $ (0.7) $ 0.2 $ (0.56)