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Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk - Commitments (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 | Dec. 31, 2020
Fixed Letters of Credit [Member] | Unused lines of Credit [Member] |  |
Company's contractual commitments due to letters of credit |  |
Loan commitments | $ 111,348 | $ 88,883
Variable Letters of Credit [Member] | Unused lines of Credit [Member] |  |
Company's contractual commitments due to letters of credit |  |
Loan commitments | 320,120 | 316,298
Letter of Credit [Member] | Unused lines of Credit [Member] |  |
Company's contractual commitments due to letters of credit |  |
Loan commitments | 431,468 | $ 405,181
Revision of Prior Period, Adjustment [Member] | Accounting Standards Update 2016-13 |  |
Company's contractual commitments due to letters of credit |  |
Provision for Unfunded Commitments | $ 1,700 |

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