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Business Combination - PCD Loans (Details) - Umpqua Bank and Columbia Banking System Merger $ in Thousands	Feb. 28, 2023 USD ($)
Asset Acquisition [Line Items]
Financing Receivable, Purchased with Credit Deterioration, Amount at Par Value	$ 478,648
Initial ACL on PCD loans acquired during the period	26,492
Financing Receivable, Purchased with Credit Deterioration, Discount (Premium)	(49,337)
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price	$ 402,819

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 50
-Name Accounting Standards Codification
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Amount of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 19
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-19

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Amount at par value of financing receivable purchased with credit deterioration.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 19
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-19

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Amount at purchase price of financing receivable purchased with credit deterioration.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 19
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-19

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Amount of discount (premium) attributable to other factors on financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 19
-Subparagraph (c)
-Publisher FASB
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