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Commitments and Contingencies - Narrative (Details) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Apr. 08, 2019 office
Unrecorded Unconditional Purchase Obligation |  |  |  |
Operating leases, rent expense | $ 5.1 | $ 4.8 | $ 3.2 |
Construction Contracts |  |  |  |
Unrecorded Unconditional Purchase Obligation |  |  |  |
Commitments under construction contracts | $ 4.6 |  |  |
Related Entity |  |  |  |
Unrecorded Unconditional Purchase Obligation |  |  |  |
Ownership percentage in partnership | 50.00% |  |  |
Idaho Independent Bank [Member] |  |  |  |
Unrecorded Unconditional Purchase Obligation |  |  |  |
Number of banking offices | office |  |  |  | 11
Community 1st Bank [Member] |  |  |  |
Unrecorded Unconditional Purchase Obligation |  |  |  |
Number of banking offices | office |  |  |  | 3
Mortgage loans originated for sale |  |  |  |
Unrecorded Unconditional Purchase Obligation |  |  |  |
Guarantor Obligations, Current Carrying Value | $ 0.6 | $ 0.9 |  |

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