v2.4.1.9

Loans (Analysis of Nonaccrual Loans) (Details) (USD $) In Thousands, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014
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Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | $ 31,828 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus | $ 31,352 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Unpaid Principal Balance Nonaccrual Loans | 37,798 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus | 44,774 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus
Consumer Portfolio Segment [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 2,868 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 2,939 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Unpaid Principal Balance Nonaccrual Loans | 3,799 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 3,930 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Secured Loans [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 17,240 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_SecuredLoansMember | 16,552 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_SecuredLoansMember
Unpaid Principal Balance Nonaccrual Loans | 20,573 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_SecuredLoansMember | 21,453 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_SecuredLoansMember
Unsecured Loans [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 189 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_UnsecuredLoansMember | 247 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_UnsecuredLoansMember
Unpaid Principal Balance Nonaccrual Loans | 211 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_UnsecuredLoansMember | 269 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_UnsecuredLoansMember
One-to-Four Family Residential [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 4,429 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OneToFourFamilyResidentialMember | 2,822 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OneToFourFamilyResidentialMember
Unpaid Principal Balance Nonaccrual Loans | 6,109 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OneToFourFamilyResidentialMember | 5,680 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OneToFourFamilyResidentialMember
Commercial Land [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 1,616 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_CommercialLandMember | 821 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_CommercialLandMember
Unpaid Principal Balance Nonaccrual Loans | 1,560 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_CommercialLandMember | 1,113 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_CommercialLandMember
Income Property Multifamily [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 887 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_IncomePropertyMultifamilyMember | 3,200 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_IncomePropertyMultifamilyMember
Unpaid Principal Balance Nonaccrual Loans | 887 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_IncomePropertyMultifamilyMember | 5,521 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_IncomePropertyMultifamilyMember
Owner Occupied [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 1,995 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OwnerOccupiedMember | 3,826 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OwnerOccupiedMember
Unpaid Principal Balance Nonaccrual Loans | 2,036 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OwnerOccupiedMember | 5,837 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OwnerOccupiedMember
Land And Acquisition [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 871 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_LandAndAcquisitionMember | 95 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_LandAndAcquisitionMember
Unpaid Principal Balance Nonaccrual Loans | 871 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_LandAndAcquisitionMember | 112 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_LandAndAcquisitionMember
Residential Construction [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 1,263 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_ResidentialConstructionMember | 370 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_ResidentialConstructionMember
Unpaid Principal Balance Nonaccrual Loans | 1,263 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_ResidentialConstructionMember | 370 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_ResidentialConstructionMember
Owner Occupied Construction [Member] |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Recorded Investment Nonaccrual Loans | 470 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OwnerOccupiedConstructionMember |
Unpaid Principal Balance Nonaccrual Loans | $ 489 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OwnerOccupiedConstructionMember | $ 489 colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = colb_OwnerOccupiedConstructionMember

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- Definition Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5111-111524 + Details
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