Income Taxes - Components of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
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| Income Taxes | ||
| Capitalized research and development expenses | $ 11,500 | $ 15,735 |
| Net operating loss carryforwards | 17,638 | 18,181 |
| Research and development and other tax credit carryforwards | 13,454 | 12,343 |
| Stock compensation | 5,158 | 4,737 |
| Unearned revenue | 3,462 | 3,635 |
| Other | 401 | 930 |
| Total deferred tax assets | 51,613 | 55,561 |
| Valuation allowance | (51,613) | (55,561) |
| (Decrease) increase in the valuation allowance | $ (3,900) | $ (2,000) |
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs expensed in connection with a business combination. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- Definition Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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