| Summary of Significant Accounting Policies - Goodwill (Details) | 12 Months Ended | 
|---|---|
| Dec. 31, 2020  USD ($) | |
| Summary of Significant Accounting Policies | |
| Number of reporting units | 1 | 
| Impairment of goodwill | $ 0 | 
| X | ||||||||||
| 
- References No definition available. 
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| X | ||||||||||
| 
- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment. No definition available. 
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