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Investment Securities - Pledged and Transferred Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	$ 906,329	$ 238,570
State of California
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	230,211	236,833
Public deposits
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	228,970	235,587
Trust deposits
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	674	677
Internal checking account
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	567	569
Bankruptcy trustee deposits
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	1,700	1,737
FHLB Securities Backed Credit Program
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	395,780	0
Federal Reserve Bank Term Funding Program
Financial Instruments Owned and Pledged as Collateral [Line Items]
Available-for-sale securities pledged as collateral	$ 278,638	$ 0

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- Definition

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+ References

No definition available.

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 12
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226013-175313

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