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Merger - Narrative (Details) - USD ($) |  | 3 Months Ended
--- | --- | ---
Aug. 06, 2021 | Mar. 31, 2022 | Dec. 31, 2021 | Mar. 31, 2021
Business Combination, Separately Recognized Transactions [Line Items] |  |  |  |
Goodwill |  | $ 72,754,000 | $ 72,754,000 |
Core deposit intangible, net |  | 6,225,000 | 6,605,000 |
Amortization of core deposit intangible |  | 380,000 | $ 393,000 | $ 204,000
American River Bank (ARB) Merger |  |  |  |
Business Combination, Separately Recognized Transactions [Line Items] |  |  |  |
Investment securities | $ 297,800,000 |  |  |
Loans | 419,400,000 |  |  |
Deposits | 790,000,000 |  |  |
Goodwill | 42,600,000 |  |  |
American River Bank (ARB) Merger | Core Deposits |  |  |  |
Business Combination, Separately Recognized Transactions [Line Items] |  |  |  |
Core deposit intangible, net | $ 3,900,000 |  |  |
Amortization of core deposit intangible |  | $ 184,000 |  | $ 0
Intangible useful life |  | 10 years |  |
Impairment loss intangible assets |  | $ 0 |  |
American River Bank (ARB) Merger | Bank of Marin |  |  |  |
Business Combination, Separately Recognized Transactions [Line Items] |  |  |  |
Merger agreement, shares exchange ratio (in shares) | 0.575 |  |  |
Business combination, number of common stock issued (in shares) | 3,441,235 |  |  |

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