XML 41 R47.htm IDEA: XBRL DOCUMENT v2.4.1.9
Loans Loans (Analysis of Troubled Debt Restructurings) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Modifications
Mar. 31, 2014
Modifications
Dec. 31, 2014
Financing Receivable, Modifications [Line Items]      
Financing Receivable Modifications Additional Commitment To Lend 0colb_FinancingReceivableModificationsAdditionalCommitmentToLend   $ 0colb_FinancingReceivableModificationsAdditionalCommitmentToLend
Loans, Excluding Purchased Credit Impaired Loans [Member]      
Financing Receivable, Modifications [Line Items]      
Number of TDR Modifications 0colb_FinancingReceivableModificationsNumberOfContractsDuration
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
5colb_FinancingReceivableModificationsNumberOfContractsDuration
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Pre-Modification Outstanding Recorded Investment   1,183colb_FinancingReceivableModificationsPreModificationRecordedInvestmentDuration
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Post-Modification Outstanding Recorded Investment   1,166colb_FinancingReceivableModificationsPostModificationRecordedInvestmentDuration
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Loans, Excluding Purchased Credit Impaired Loans [Member] | Secured Loans [Member]      
Financing Receivable, Modifications [Line Items]      
Number of TDR Modifications   2colb_FinancingReceivableModificationsNumberOfContractsDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_SecuredLoansMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Pre-Modification Outstanding Recorded Investment   546colb_FinancingReceivableModificationsPreModificationRecordedInvestmentDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_SecuredLoansMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Post-Modification Outstanding Recorded Investment   546colb_FinancingReceivableModificationsPostModificationRecordedInvestmentDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_SecuredLoansMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Loans, Excluding Purchased Credit Impaired Loans [Member] | One-to-Four Family Residential [Member]      
Financing Receivable, Modifications [Line Items]      
Number of TDR Modifications   2colb_FinancingReceivableModificationsNumberOfContractsDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_OneToFourFamilyResidentialMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Pre-Modification Outstanding Recorded Investment   494colb_FinancingReceivableModificationsPreModificationRecordedInvestmentDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_OneToFourFamilyResidentialMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Post-Modification Outstanding Recorded Investment   494colb_FinancingReceivableModificationsPostModificationRecordedInvestmentDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_OneToFourFamilyResidentialMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Loans, Excluding Purchased Credit Impaired Loans [Member] | Income Property Multifamily [Member]      
Financing Receivable, Modifications [Line Items]      
Number of TDR Modifications   1colb_FinancingReceivableModificationsNumberOfContractsDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_IncomePropertyMultifamilyMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Pre-Modification Outstanding Recorded Investment   143colb_FinancingReceivableModificationsPreModificationRecordedInvestmentDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_IncomePropertyMultifamilyMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember
 
Post-Modification Outstanding Recorded Investment   $ 126colb_FinancingReceivableModificationsPostModificationRecordedInvestmentDuration
/ us-gaap_FinancingReceivableTroubledDebtRestructuringAxis
= colb_IncomePropertyMultifamilyMember
/ colb_LoansByMajorCategoryAxis
= colb_LoansExcludingPurchasedCreditImpairedLoansMember