| Summary of Significant Accounting Policies - Interest income (Details) - USD ($) | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | |
| Summary of Significant Accounting Policies | |||
| Amortization (accretion) of the premium (discount) | $ 2,525,000 | $ 5,276,000 | $ 3,836,000 | 
| X | ||||||||||
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- References No definition available. 
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| X | ||||||||||
| 
- Definition Amount of accretion (amortization) of purchase discount (premium) on nonoperating securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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