SUPPLEMENTARY DATA - QUARTERLY RESULTS OF OPERATION (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
Schedule Of Quarterly Financial Information [Line Items]                    
Net revenues $ 74 $ 83 $ 92 $ 2,717 $ 3,765 $ 218 $ 257 $ 224 $ 2,966 $ 4,464
Operating expenses 1,828 2,145 2,083 2,135 2,036 2,287 3,336 3,362 8,191 11,021
Operating (loss) income (1,754) (2,062) (1,991) 582 1,729 (2,069) (3,079) (3,138) (5,225) (6,557)
Net (loss) income $ (1,738) $ (2,200) $ (2,149) $ 405 $ 1,534 $ (2,250) $ (3,288) $ (3,384) $ (5,682) $ (7,388)
Basic (loss) income per share $ (0.08) $ (0.12) $ (0.18) $ 0.03 $ 0.13 $ (0.19) $ (0.28) $ (0.28) $ (0.36) $ (0.62)
Diluted (loss) income per share $ (0.08) $ (0.12) $ (0.18) $ 0.03 $ 0.13 $ (0.19) $ (0.28) $ (0.28) $ (0.36) $ (0.62)