Condensed Statements of Operations (Parenthetical) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2016 |
Jun. 30, 2015 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Research and Development Expenses [Member] | ||||||
| Non-cash stock-based compensation expenses | $ 88 | $ 203 | $ 160 | $ 378 | $ 632 | $ 836 |
| General and Administrative Expenses [Member] | ||||||
| Non-cash stock-based compensation expenses | $ 139 | $ 244 | $ 361 | $ 480 | $ 903 | $ 1,010 |