Stock-Based Compensation - Restricted Stock Units (Details) - USD ($) $ in Thousands  | 
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2021  | 
Sep. 30, 2020  | 
Sep. 30, 2021  | 
Sep. 30, 2020  | 
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Total stock-based compensation expense | $ 28,493 | $ 550 | $ 29,265 | $ 1,692 | 
| Stock-based compensation, cost unrecognized, period for recognition | 1 year 1 month 6 days | |||
| Restricted stock units | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Stock-based compensation, cost unrecognized | $ 37,100 | $ 37,100 | ||
| Stock-based compensation, cost unrecognized, period for recognition | 2 years 4 months 24 days | |||
| X | ||||||||||
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Definition Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Details 
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