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Derivatives and Balance Sheet Offsetting Balance Sheet Offsetting (Details) (USD $)
In Thousands, unless otherwise specified |
Mar. 31, 2015
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Dec. 31, 2014
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| Balance Sheet Offsetting [Line Items] | ||
| Repurchase agreements, amounts offset in balance sheet | $ 0colb_Repurchaseagreementsamountsoffsetinbalancesheet | $ 0colb_Repurchaseagreementsamountsoffsetinbalancesheet |
| Repurchase agreements, net amount presented in statement of financial position | 96,852colb_Repurchaseagreementsnetamountpresentedinstatementoffinancialposition | 105,080colb_Repurchaseagreementsnetamountpresentedinstatementoffinancialposition |
| Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities | (96,852)us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities | (105,080)us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities |
| Securities sold under agreements to repurchase, amount not offset | 0colb_Securitiessoldunderagreementstorepurchaseamountnotoffset | 0colb_Securitiessoldunderagreementstorepurchaseamountnotoffset |
| Interest Rate Contracts [Member] | ||
| Balance Sheet Offsetting [Line Items] | ||
| Derivative Assets, Gross Amounts Offset in the Balance Sheets | 0colb_DerivativeAssetsGrossAmountsOffsetintheBalanceSheets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
0colb_DerivativeAssetsGrossAmountsOffsetintheBalanceSheets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Derivative Asset | 14,244us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
11,800us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Derivative, Collateral, Obligation to Return Securities | 0us-gaap_DerivativeCollateralObligationToReturnSecurities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
0us-gaap_DerivativeCollateralObligationToReturnSecurities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 14,244us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
11,800us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Derivative Liability, Gross Amounts Offset in Balance Sheets | 0colb_DerivativeLiabilityGrossAmountsOffsetinBalanceSheets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
0colb_DerivativeLiabilityGrossAmountsOffsetinBalanceSheets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Derivative Liability | 14,300us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
11,851us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Derivative, Collateral, Right to Reclaim Securities | (14,300)us-gaap_DerivativeCollateralRightToReclaimSecurities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
(11,851)us-gaap_DerivativeCollateralRightToReclaimSecurities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 0us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
0us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember |
| Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Assets [Member] | ||
| Balance Sheet Offsetting [Line Items] | ||
| Fair value of asset derivative instruments | 14,244us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherAssetsMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember / us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis = us-gaap_NondesignatedMember |
11,800us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherAssetsMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember / us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis = us-gaap_NondesignatedMember |
| Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Liabilities [Member] | ||
| Balance Sheet Offsetting [Line Items] | ||
| Fair value of liability derivative instruments | 14,300us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherLiabilitiesMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember / us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis = us-gaap_NondesignatedMember |
11,851us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherLiabilitiesMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateContractMember / us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis = us-gaap_NondesignatedMember |
| Available-for-sale Securities [Member] | ||
| Balance Sheet Offsetting [Line Items] | ||
| Securities Sold under Agreements to Repurchase, Gross | $ 96,852us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseGross / us-gaap_AssetsSoldUnderAgreementsToRepurchaseAxis = us-gaap_AvailableforsaleSecuritiesMember |
$ 105,080us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseGross / us-gaap_AssetsSoldUnderAgreementsToRepurchaseAxis = us-gaap_AvailableforsaleSecuritiesMember |
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- Definition
Derivative Assets, Gross Amounts Offset in the Balance Sheets No definition available.
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Derivative Liability, Gross Amounts Offset in Balance Sheets No definition available.
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Repurchase agreements, amounts offset in balance sheet No definition available.
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Repurchase Agreements, Net Amount Presented in Balance Sheets No definition available.
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Securities sold under agreements to repurchase, amount not offset No definition available.
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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of obligation to return securities collateral under master netting arrangements that have not been offset against derivative assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of right to receive securities collateral under master netting arrangements that have not been offset against derivative liabilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of right to receive securities collateral under master netting arrangements that have not been offset against securities sold under agreement to repurchase. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount, before effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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