STOCK-BASED COMPENSATION (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Stock-based compensation expense related to stock-based awards | |||
| Total stock-based compensation expense | $ 5,987,000 | $ 7,832,000 | $ 7,403,000 |
| Incremental stock-based compensation expense | 1,400,000 | 1,100,000 | |
| General and administrative | |||
| Stock-based compensation expense related to stock-based awards | |||
| Total stock-based compensation expense | 4,490,000 | 4,230,000 | 3,303,000 |
| Research and development | |||
| Stock-based compensation expense related to stock-based awards | |||
| Total stock-based compensation expense | 1,497,000 | 3,103,000 | $ 4,100,000 |
| Restructuring charges | |||
| Stock-based compensation expense related to stock-based awards | |||
| Total stock-based compensation expense | $ 499,000 | $ 499,000 | |
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- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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- Definition An excess of the fair value of the modified award over the fair value of the award immediately before the modification. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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