Revenue Recognition - Changes in Contractual Liabilities Balance (Details) - USD ($) |
3 Months Ended | 42 Months Ended |
|---|---|---|
Mar. 31, 2021 |
Mar. 31, 2021 |
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| Contract with Customer, Liability [Abstract] | ||
| Beginning balance | $ 16,378,000 | |
| Revenue recognized | 790,000 | $ 0 |
| Ending balance | $ 15,588,000 | $ 15,588,000 |
| 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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