Stockholders' Equity (Details 3) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Employee Benefits and Share-based Compensation | $ 3,117 | $ 3,867 | $ 3,252 |
| Research and development | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Employee Benefits and Share-based Compensation | 1,180 | 2,557 | 2,987 |
| General and administrative | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Employee Benefits and Share-based Compensation | $ 1,937 | $ 1,310 | $ 265 |
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- Definition Amount of cost (reversal of cost) for employee benefits and share-based payment arrangement. Includes, but is not limited to, pension, other postretirement, postemployment and termination benefits. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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