Summary of Significant Accounting Policies - Contract Liabilities (Details) - USD ($) |
9 Months Ended | |
|---|---|---|
Sep. 30, 2019 |
Dec. 31, 2018 |
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| Contract with Customer, Liability [Abstract] | ||
| Amounts included in contract liability at the beginning of the period | $ 2,686,000 | |
| Deferred Revenue | ||
| Contract with Customer, Liability [Abstract] | ||
| Deferred Revenue | $ 2,686,000 |
| X | ||||||||||
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Details
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