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Merger - Narrative (Details) $ in Thousands | Aug. 06, 2021 USD ($) shares | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
--- | --- | --- | ---
Business Combination, Separately Recognized Transactions [Line Items] |  |  |
Goodwill |  | $ 72,754 | $ 72,754
American River Bank (ARB) Merger |  |  |
Business Combination, Separately Recognized Transactions [Line Items] |  |  |
Assets | $ 898,400 |  |
Investment securities acquired | 297,800 |  |
Loans | 419,400 |  |
Liabilities | 816,600 |  |
Deposits | 790,000 |  |
Goodwill | 42,600 |  |
Total merger consideration | 124,477 |  |
Net assets acquired | $ 81,900 |  |
American River Bank (ARB) Merger | Bank of Marin |  |  |
Business Combination, Separately Recognized Transactions [Line Items] |  |  |
Business combination, number of common stock issued (in shares) | shares | 3,441,235 |  |
American River Bank (ARB) Merger | Common Stock |  |  |
Business Combination, Separately Recognized Transactions [Line Items] |  |  |
Fixed exchange ratio | 0.575 |  |

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