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Merger - Business Acquisition, Pro Forma Information (Details) - American River Bank (ARB) Merger - USD ($) $ in Thousands	5 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition, Pro Forma Information [Abstract]
Net interest income - Pro forma	$ 9,167	$ 120,513	$ 122,608
Net interest income - Actual		104,951	96,659
Net income - Pro forma	$ (1,444)	42,997	28,445
Net income - Actual		33,228	30,242
Total merger-related one-time and conversion costs		6,458	$ 0
American River Bank ARB
Business Acquisition, Pro Forma Information [Abstract]
Total merger-related one-time and conversion costs		3,000
Bank of Marin
Business Acquisition, Pro Forma Information [Abstract]
Total merger-related one-time and conversion costs		$ 4,900

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The amount of cash paid during the reporting period for charges associated with the mergers.

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