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Investment Securities - Schedule of Financial Instruments Owned and Pledged as Collateral (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	$ 913,169	$ 941,122
Total investment securities pledged to the State of California
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	322,154	290,564
Secure public deposits in compliance with the Local Agency Security Program
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	319,454	288,385
Collateral for trust deposits
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	1,200	1,284
Collateral for Wealth Management and Trust Services checking account
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	1,500	895
Bankruptcy trustee deposits pledged with Federal Reserve Bank
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	2,138	651
Pledged to FHLB Securities-Backed Credit Program
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	269,768	284,148
Pledged to the Federal Reserve Discount Window
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total pledged investment securities	$ 319,109	$ 365,759

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(11))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481444/860-30-45-1

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- Definition

Fair value of the securities pledged as collateral against securities loaned.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483444/210-20-55-12

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483466/210-20-50-3

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