XML 20 R78.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Fair Value of Financial Instruments and Fair Value Measurements, Quantitative Information (Details) (USD $) | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013
Impaired Loans [Member] | Commercial [Member] | Nonrecurring [Member] |  |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |  |
Assets measured at fair value |  |  | 1,019,084 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = cban_ImpairedLoansMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Impaired Loans [Member] | Sales Comparison [Member] | Commercial [Member] | Nonrecurring [Member] | Minimum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) |  |  | 0.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_ImpairedLoansMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) |  |  | 10.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_ImpairedLoansMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Impaired Loans [Member] | Sales Comparison [Member] | Commercial [Member] | Nonrecurring [Member] | Maximum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) |  |  | 15.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_ImpairedLoansMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) |  |  | 50.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_ImpairedLoansMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Impaired Loans [Member] | Sales Comparison [Member] | Commercial [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) |  |  | (7.50%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_ImpairedLoansMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) |  |  | (30.00%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_ImpairedLoansMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Commercial Construction [Member] | Nonrecurring [Member] |  |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |  |
Assets measured at fair value | 82,422 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |  | 2,641,041 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Real Estate [Member] | Residential Real Estate [Member] | Nonrecurring [Member] |  |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |  |
Assets measured at fair value | 1,650,474 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember |  | 1,323,296 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember |
Real Estate [Member] | Commercial Real Estate [Member] | Nonrecurring [Member] |  |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |  |
Assets measured at fair value | 5,678,297 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |  | 5,450,788 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Real Estate [Member] | Farmland [Member] | Nonrecurring [Member] |  |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |  |
Assets measured at fair value | 367,086 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember |  | 1,241,482 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember |
Real Estate [Member] | Sales Comparison [Member] | Commercial Construction [Member] | Nonrecurring [Member] | Minimum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (22.00%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (16.00%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 0.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 0.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Commercial Construction [Member] | Nonrecurring [Member] | Maximum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | 38.10%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 28.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 10.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 10.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Commercial Construction [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (8.05%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (6.00%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | (5.00%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (5.00%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Residential Real Estate [Member] | Nonrecurring [Member] | Minimum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (2.30%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 0.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 0.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 0.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Residential Real Estate [Member] | Nonrecurring [Member] | Maximum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | 191.70%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 46.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 10.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 25.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Residential Real Estate [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (94.70%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (23.00%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | (5.00%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (12.50%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Commercial Real Estate [Member] | Nonrecurring [Member] | Minimum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | 0.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (27.20%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 0.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 25.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Commercial Real Estate [Member] | Nonrecurring [Member] | Maximum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | 0.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 216.80%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 90.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 90.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Commercial Real Estate [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | 0.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (94.80%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | (45.00%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (57.50%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Farmland [Member] | Nonrecurring [Member] | Minimum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (8.30%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (55.00%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 10.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 10.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Farmland [Member] | Nonrecurring [Member] | Maximum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | 252.50%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 388.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 50.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 35.00%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Sales Comparison [Member] | Farmland [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (122.10%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (166.50%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | (30.00%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (22.50%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = cban_FarmlandMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Real Estate [Member] | Income Approach [Member] | Commercial Construction [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Capitalization Rate (in hundredths) |  |  | 8.50%cban_FairValueInputsCapitalizationRate / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = us-gaap_IncomeApproachValuationTechniqueMember |
Real Estate [Member] | Income Approach [Member] | Residential Real Estate [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Capitalization Rate (in hundredths) | 13.75%cban_FairValueInputsCapitalizationRate / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = us-gaap_IncomeApproachValuationTechniqueMember |  |  |
Real Estate [Member] | Income Approach [Member] | Commercial Real Estate [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Capitalization Rate (in hundredths) | 11.00%cban_FairValueInputsCapitalizationRate / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = us-gaap_IncomeApproachValuationTechniqueMember |  | 11.00%cban_FairValueInputsCapitalizationRate / us-gaap_FairValueByAssetClassAxis = us-gaap_RealEstateMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = us-gaap_IncomeApproachValuationTechniqueMember |
Other Real Estate Owned [Member] | Nonrecurring [Member] |  |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |  |
Assets measured at fair value | 6,128,365 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember |  | 7,019,799 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember |
Other Real Estate Owned [Member] | Sales Comparison [Member] | Nonrecurring [Member] | Minimum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (40.00%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (10.00%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 0.33%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 0.36%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Other Real Estate Owned [Member] | Sales Comparison [Member] | Nonrecurring [Member] | Maximum [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | 45.00%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 319.10%us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | 69.36%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | 87.81%cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Other Real Estate Owned [Member] | Sales Comparison [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Adjustment for Differences Between the Comparable Sales (in hundredths) | (2.50%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (154.55%)us-gaap_FairValueInputsComparabilityAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Management Adjustments for Age of Appraisals and/or Current Market Conditions (in hundredths) | (31.88%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |  | (29.99%)cban_FairValueInputsComparabilityManagementAdjustments / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = cban_SalesComparisonApproachValuationTechniqueMember |
Other Real Estate Owned [Member] | Income Approach [Member] | Nonrecurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Discount Rate (in hundredths) | 9.00%us-gaap_FairValueInputsDiscountRate / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = us-gaap_IncomeApproachValuationTechniqueMember |  | 10.00%us-gaap_FairValueInputsDiscountRate / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = us-gaap_IncomeApproachValuationTechniqueMember |
Capitalization Rate (in hundredths) | 10.00%cban_FairValueInputsCapitalizationRate / us-gaap_FairValueByAssetClassAxis = cban_OtherRealEstateOwnedMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsNonrecurringMember / us-gaap_RangeAxis = us-gaap_WeightedAverageMember / us-gaap_ValuationTechniqueAxis = us-gaap_IncomeApproachValuationTechniqueMember |  |  |
State, County and Municipal [Member] | Recurring [Member] |  |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |  |
Assets measured at fair value | 948,390 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = cban_StateCountyAndMunicipalMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember |  | 941,265 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = cban_StateCountyAndMunicipalMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember |
State, County and Municipal [Member] | Discounted Cash Flow Member] | Recurring [Member] | Weighted Average [Member] |  |  |  |
Unobservable Inputs [Abstract] |  |  |  |
Discount Rate (in hundredths) |  | [1] |  | [1]
[1] | The Company relies on a third-party pricing service to value its municipal securities. The details of the unobservable inputs and other adjustments used by the third-party pricing service were not readily available to the Company.

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