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Significant Accounting Policies - Additional Information (Details) - USD ($) |  | 12 Months Ended
--- | --- | ---
Dec. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Financing Receivable, Impaired [Line Items] |  |  |  |
Date of discontinued recognition of interest on mortgage and commercial loans |  | 90 days |  |
Consumer and other retail loan due date |  | 120 days |  |
Interest receivable | $ 33,679,000 | $ 56,459,000 | $ 33,679,000 |
Minimum duration for past due residential loans to be considered as nonperforming |  | 90 days |  |
Impairment of company's goodwill |  | $ 0 | $ 0 | $ 0
Lock in period for interest rates |  | 45 days |  |
Remaining purchase discount on loans | (50,958,000) |  |  |
Cumulative Effect, Period of Adoption, Adjustment |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Remaining purchase discount on loans | $ 5,469,000 |  |  |
Minimum |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Renewal term |  | 1 year |  |
Minimum | Lease financing |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Maturity term |  | 2 years |  |
Minimum | Residential | Real estate - construction |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Maturity term |  | 6 months |  |
Minimum | Commercial | Real estate - construction |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Maturity term |  | 24 months |  |
Maximum |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Renewal term |  | 20 years |  |
Maximum | Lease financing |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Maturity term |  | 5 years |  |
Maximum | Residential | Real estate - construction |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Maturity term |  | 12 months |  |
Maximum | Commercial | Real estate - construction |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Maturity term |  | 36 months |  |
Premises |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Estimated life (in years) |  | 40 years |  |
Furniture and equipment | Minimum |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Estimated life (in years) |  | 3 years |  |
Furniture and equipment | Maximum |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Estimated life (in years) |  | 7 years |  |
Computer equipment | Minimum |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Estimated life (in years) |  | 3 years |  |
Computer equipment | Maximum |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |
Estimated life (in years) |  | 5 years |  |

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