XML 88 R73.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Loans Loans (Analysis of Troubled Debt Restructurings) (Details) $ in Thousands, loan in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 USD ($) Modifications contract | Dec. 31, 2015 USD ($) Modifications loan contract | Dec. 31, 2014 USD ($) Modifications contract
Financing Receivable, Modifications [Line Items] |  |  |
Financing Receivable Modifications Additional Commitment To Lend | $ 508 | $ 0 |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract | 0 | 0 | 0
FHLB Advances, Collateral Pledged | $ 1,510,514 | $ 1,399,201 |
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing, Number of Loans | loan |  | 0.0 |
Loans, Excluding Purchased Credit Impaired Loans [Member] |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Modifications | 54 | 7 | 8
Pre-Modification Outstanding Recorded Investment | $ 7,679 | $ 3,808 | $ 2,892
Post-Modification Outstanding Recorded Investment | $ 7,677 | $ 3,790 | $ 2,875
Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Secured loans [Member] |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Modifications | 9 | 5 | 4
Pre-Modification Outstanding Recorded Investment | $ 2,131 | $ 3,724 | $ 759
Post-Modification Outstanding Recorded Investment | $ 2,131 | $ 3,706 | $ 759
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: One-to-four family residential [Member] |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Modifications | 3 | 1 | 2
Pre-Modification Outstanding Recorded Investment | $ 203 | $ 30 | $ 494
Post-Modification Outstanding Recorded Investment | $ 203 | $ 30 | $ 494
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Income property [Member] |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Modifications | 0 | 0 | 1
Pre-Modification Outstanding Recorded Investment | $ 0 | $ 0 | $ 143
Post-Modification Outstanding Recorded Investment | $ 0 | $ 0 | $ 126
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Owner occupied [Member] |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Modifications | 1 | 0 | 1
Pre-Modification Outstanding Recorded Investment | $ 250 | $ 0 | $ 1,496
Post-Modification Outstanding Recorded Investment | $ 250 | $ 0 | $ 1,496
Loans, Excluding Purchased Credit Impaired Loans [Member] | Consumer [Member] |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Modifications | 41 | 1 | 0
Pre-Modification Outstanding Recorded Investment | $ 5,095 | $ 54 | $ 0
Post-Modification Outstanding Recorded Investment | $ 5,093 | $ 54 | $ 0

X
- Definition Financing Receivable Modifications Additional Commitment To Lend + References No definition available. + Details
Name: | colb_FinancingReceivableModificationsAdditionalCommitmentToLend
Namespace Prefix: | colb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing, Number of Loans + References No definition available. + Details
Name: | colb_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruingNumberOfLoans
Namespace Prefix: | colb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of the collateral pledged in support of federal home loan bank advances outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
Name: | us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Post-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Pre-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | colb_LoansByMajorCategoryAxis=colb_LoansExcludingPurchasedCreditImpairedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=colb_SecuredLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=colb_OneToFourFamilyResidentialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=colb_IncomePropertyMultifamilyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=colb_OwnerOccupiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |