| STOCK-BASED COMPENSATION (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
| Stock-based compensation expense related to stock-based awards | |||
| Total stock-based compensation expense | $ 7,295 | $ 9,115 | $ 7,704 | 
| Selling, general and administrative | |||
| Stock-based compensation expense related to stock-based awards | |||
| Total stock-based compensation expense | 5,223 | 6,453 | 5,383 | 
| Research and development | |||
| Stock-based compensation expense related to stock-based awards | |||
| Total stock-based compensation expense | $ 2,072 | $ 2,662 | $ 2,321 | 
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- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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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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