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Subsequent Events (Details) - Columbia Banking Systems and Pacific Premier Bancorp Merger | Apr. 23, 2025 shares
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Subsequent Event [Line Items] |
Business Acquisition, Equity Interest Issued or Issuable, Share Exchange Ratio | 0.9150
Business Acquisition, Expected Percentage Of Voting Interests To Be Held By Acquiree Stockholders | 30.00%

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- Definition Business Acquisition, Expected Percentage Of Voting Interests To Be Held By Acquiree Stockholders + References No definition available. + Details
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Balance Type: | na
Period Type: | instant

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- Definition Business Combination, Expected Consideration To Be Transferred, Equity Interests Issued and Issuable, Share + References No definition available. + Details
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Namespace Prefix: | colb_
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Balance Type: | na
Period Type: | duration

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- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481674/830-30-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 855 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483399/855-10-50-2 + Details
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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |