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Commitments and Contingencies - Off Balance Sheet Arrangements (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Total commitments and standby letters of credit |  |
Other Commitments [Line Items] |  |
Total commitments and standby letters of credit | $ 602,575 | $ 604,442
Commercial lines of credit |  |
Other Commitments [Line Items] |  |
Total commitments and standby letters of credit | 300,308 | 297,898
Revolving home equity lines |  |
Other Commitments [Line Items] |  |
Total commitments and standby letters of credit | 204,846 | 191,969
Undisbursed construction loans |  |
Other Commitments [Line Items] |  |
Total commitments and standby letters of credit | 82,782 | 101,307
Personal and other lines of credit |  |
Other Commitments [Line Items] |  |
Total commitments and standby letters of credit | 10,981 | 10,611
Standby letters of credit |  |
Other Commitments [Line Items] |  |
Total commitments and standby letters of credit | $ 3,658 | $ 2,657

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