Investment Securities - Schedule of Financial Instruments Owned and Pledged as Collateral (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	$ 751,082	$ 838,202
Total investment securities pledged to the State of California
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	264,910	313,813
Secure public deposits in compliance with the Local Agency Security Program
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	262,677	311,543
Collateral for trust deposits
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	991	1,010
Collateral for Wealth Management and Trust Services checking account
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	1,242	1,260
Bankruptcy trustee deposits pledged with Federal Reserve Bank
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	1,940	1,992
Pledged to FHLB Securities-Backed Credit Program
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	219,242	224,787
Pledged to the Federal Reserve Discount Window
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	$ 264,990	$ 297,610