XML 112 R97.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Fair Value Accounting and Measurement (Quantitative Information About Level 3 Fair Value Measurements) (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs, Assets, Quantitative Information [Table Text Block] | The range and weighted-average of the significant unobservable inputs used to fair value our Level 3 nonrecurring assets during 2016 and 2015, along with the valuation techniques used, are shown in the following tables:
|  | Fair value at December 31, 2016 |  | Valuation Technique |  | Unobservable Input |  | Range (Weighted Average) (1)
|  | (dollars in thousands)
Impaired loans - collateral-dependent (3) |  | $ | 2,248 |  |  | Fair Market Value of Collateral |  | Adjustment to Stated Value |  | N/A (2)
Impaired loans - other |  | $ | 1,539 |  |  | Discounted Cash Flow |  | Discount Rate |  | 4.50% - 6.50% (5.26%)
OREO |  | $ | 4,388 |  |  | Fair Market Value of Collateral |  | Adjustment to Appraisal Value |  | N/A (2)
(1) Discount rate used in discounted cash flow valuation.
(2) Quantitative disclosures are not provided for collateral-dependent impaired loans and OREO because there were no adjustments made to the appraisal values or stated values during the current period.
(3) Collateral consists of accounts receivable, inventory, equipment, and real property.
|  | Fair value at December 31, 2015 |  | Valuation Technique |  | Unobservable Input |  | Range (Weighted Average) (1)
|  | (dollars in thousands)
Impaired loans - real estate collateral |  | $ | 380 |  |  | Fair Market Value of Collateral |  | Adjustment to Appraisal Value |  | N/A (2)
Impaired loans - other collateral (3) |  | $ | 378 |  |  | Fair Market Value of Collateral |  | Adjustment to Stated Value |  | N/A (2)
OREO |  | $ | 4,524 |  |  | Fair Market Value of Collateral |  | Adjustment to Appraisal Value |  | N/A (2)
(1) Discount applied to appraisal value, letter of intent to purchase, or stated value (in the case of equipment and life insurance).
(2) Quantitative disclosures are not provided because there were no adjustments made to the appraisal value during the current period.
(3) Other collateral consists of equipment and life insurance.
Fair Value, Measurements, Nonrecurring [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Impaired loans | $ 3,787 | $ 758
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Impaired loans | 3,787 | 758
Other Real Estate Owned, Fair Value Disclosure | $ 4,388 | $ 4,524

X
- Definition Impaired Loans, Financial Assets, Fair Value + References No definition available. + Details
Name: | colb_ImpairedLoansFinancialAssetsFairValue
Namespace Prefix: | colb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Other Real Estate Owned, Fair Value Disclosure + References No definition available. + Details
Name: | colb_OtherRealEstateOwnedFairValueDisclosure
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_FairValueInputsAssetsQuantitativeInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of quantitative information about the inputs used in the fair value measurement of assets. This disclosure may include, but is not limited to, the fair value of the asset, valuation technique used to measure fair value, the inputs used to measure fair value, the ranges of the inputs, and the weighted averages of the inputs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsAssetsQuantitativeInformationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |