XML 25 R47.htm IDEA: XBRL DOCUMENT
v3.19.3

Loans (Analysis of Nonaccrual Loans) (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | $ 37,021 | $ 54,842
Unpaid Principal Balance Nonaccrual Loans | 48,126 | 65,358
Secured Loans [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 24,408 | 35,504
Unpaid Principal Balance Nonaccrual Loans | 35,033 | 45,072
Unsecured Loans [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 0 | 9
Unpaid Principal Balance Nonaccrual Loans | 0 | 9
One-to-Four Family Residential [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 574 | 1,158
Unpaid Principal Balance Nonaccrual Loans | 594 | 1,178
Commercial Land [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 2,562 | 2,261
Unpaid Principal Balance Nonaccrual Loans | 2,570 | 2,270
Income Property Multifamily [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 997 | 2,721
Unpaid Principal Balance Nonaccrual Loans | 997 | 3,062
Owner Occupied [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 6,524 | 9,922
Unpaid Principal Balance Nonaccrual Loans | 6,633 | 10,300
Land And Acquisition [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 0 | 318
Unpaid Principal Balance Nonaccrual Loans | 0 | 318
Consumer Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Recorded Investment Nonaccrual Loans | 1,956 | 2,949
Unpaid Principal Balance Nonaccrual Loans | $ 2,299 | $ 3,149

X
- Definition Financing Receivable Unpaid Principal Balance Nonaccrual Status. + References No definition available. + Details
Name: | colb_FinancingReceivableUnpaidPrincipalBalanceNonaccrualStatus
Namespace Prefix: | colb_
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_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of financing receivable on nonaccrual status. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5111-111524 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 16 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=colb_UnsecuredLoansMember
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_CommercialLandMember
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=colb_LandAndAcquisitionMember
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: |