Stockholders' Equity (Details 2) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Employee Benefits and Share-based Compensation | $ 760 | $ 2,071 | $ 2,651 | $ 2,084 |
| Research and Development Expense [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Employee Benefits and Share-based Compensation | 411 | 2,071 | 1,635 | 2,084 |
| General and Administrative Expense [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Employee Benefits and Share-based Compensation | $ 349 | $ 0 | $ 1,016 | $ 0 |