Stockholders' Equity - Stock-Based Compensation (Details) - USD ($) $ in Thousands |
3 Months Ended | |
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Mar. 31, 2020 |
Mar. 31, 2019 |
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Total stock-based compensation expense | $ 639 | $ 798 |
| Research and development [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Total stock-based compensation expense | 144 | 196 |
| General and administrative [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Total stock-based compensation expense | $ 495 | $ 602 |
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- Definition Amount of expense for employee benefit and equity-based compensation. 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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