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v3.20.4

Summary of Significant Accounting Policies (Narrative) (Details) | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2020 USD ($) segment | Jan. 01, 2020 USD ($) segment | Dec. 31, 2019 USD ($) segment | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($)
Property, Plant and Equipment [Line Items] |  |  |  |  |
Number of segments | segment | 3 |  |  |  |
Accrued interest receivable | $ 14,133,000 |  |  |  |
Required cash on deposit at Federal Reserve | 0 |  | $ 24,560,000 |  |
Net reduction to retained earnings upon adoption of new accounting pronouncement | (624,709,000) |  | (573,820,000) | $ (458,640,000) | $ (364,571,000)
Allowance for credit losses | 46,859,000 | $ 31,931,000 | $ 16,278,000 | 15,823,000 | 15,694,000
Number of loan segments | segment |  | 8 | 6 |  |
Acquired with Deteriorated Credit Quality |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Allowance for credit losses |  |  | $ 405,000 |  |
Retained Earnings |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Net reduction to retained earnings upon adoption of new accounting pronouncement | $ (288,447,000) |  | (253,090,000) | $ (211,424,000) | $ (178,969,000)
Cumulative Effect of Change in Accounting Principles |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Net reduction to retained earnings upon adoption of new accounting pronouncement |  |  | 6,717,000 |  |
Allowance for credit losses |  | $ 15,653,000 |  |  |
Cumulative Effect of Change in Accounting Principles | Acquired with Deteriorated Credit Quality |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Allowance for credit losses |  | 6,886,000 | 6,886,000 |  |
Cumulative Effect of Change in Accounting Principles | Retained Earnings |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Net reduction to retained earnings upon adoption of new accounting pronouncement |  | $ 6,717,000 | $ 6,717,000 |  |
Minimum |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Finite-lived intangible asset, useful life | 6 years |  |  |  |
Maximum |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Finite-lived intangible asset, useful life | 10 years |  |  |  |
Buildings and related components | Minimum |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Premises, furniture, and equipment, useful life | 10 years |  |  |  |
Buildings and related components | Maximum |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Premises, furniture, and equipment, useful life | 40 years |  |  |  |
Furniture, fixtures and equipment | Minimum |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Premises, furniture, and equipment, useful life | 3 years |  |  |  |
Furniture, fixtures and equipment | Maximum |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Premises, furniture, and equipment, useful life | 10 years |  |  |  |

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