XML 104 R75.htm IDEA: XBRL DOCUMENT
v3.23.1

Fair Value Measurement (Losses Resulting From Nonrecurring Fair Value Adjustments) (Details) - Fair Value, Nonrecurring - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Losses resulting from nonrecurring fair value adjustments | $ 18,734 | $ 7,791
Loans and leases |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Losses resulting from nonrecurring fair value adjustments | $ 18,734 | $ 7,791

X
- Definition Loss Measured At Fair Value On Nonrecurring Basis + References No definition available. + Details
Name: | colb_LossMeasuredAtFairValueOnNonrecurringBasis
Namespace Prefix: | colb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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 No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=colb_LoansAndLeasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |