| Commitments and Contingencies - Other Information Related to Leases (Details) $ in Thousands | 9 Months Ended | 
|---|---|
| Sep. 30, 2019  USD ($) | |
| Commitments and Contingencies | |
| Cash paid for amounts included in the measurement of operating lease liabilities | $ 1,314 | 
| Right-to-use assets obtained in exchange for new finance lease liabilities | $ 16 | 
| Weighted-average remaining lease term - finance leases | 3 years 2 months 4 days | 
| Weighted-average remaining lease term - operating leases | 2 years 1 month 2 days | 
| Weighted-average discount rate - finance leases | 7.28% | 
| Weighted-average discount rate - operating leases | 6.28% | 
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- References No definition available. 
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- Definition Weighted average discount rate for finance lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of operating lease income from lease payments paid and payable to lessor. Excludes variable lease payments not included in measurement of lease receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Weighted average discount rate for operating lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Definition Amount of increase in right-of-use asset obtained in exchange for finance lease liability. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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