| Accrued Expenses and Long-Term Liabilities - Schedule of Long Term Liabilities (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 | 
|---|---|---|
| Payables and Accruals [Abstract] | ||
| Warrant liability | $ 732 | $ 473 | 
| Uncertain tax positions | 3,891 | 3,734 | 
| Other | 107 | 82 | 
| Long-term liabilities | $ 4,730 | $ 4,289 | 
| X | ||||||||||
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- Definition Warrant liability noncurrent. No definition available. 
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| X | ||||||||||
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- Definition Amount of obligation due after one year or beyond the normal operating cycle, if longer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Amount recognized for uncertainty in income taxes classified as noncurrent. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- References No definition available. 
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