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Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended |
--- | --- | ---
Mar. 31, 2015 | Dec. 31, 2014
Summary of Significant Accounting Policies [Abstract] |  |
Percentage of loan portfolio concentrated in loans secured by real estate (in hundredths) | 87.00%cban_PercentageOfLoanPortfolioConcentratedInLoansSecuredByRealEstate |
Discounted percentage for selling and marketing cost (in hundredths) | 10.00%cban_DiscountedPercentageForSellingAndMarketingCost |
Income Taxes [Abstract] |  |
Probability of uncertain tax positions of being realized upon settlement, minimum (in hundredths) | 50.00%cban_ProbabilityOfUncertainTaxPositionsOfBeingRealizedUponSettlementMinimum |
Bank-Owned Life Insurance [Abstract] |  |
Cash surrender value of insurance contracts | $ 14,648 us-gaap_CashSurrenderValueOfLifeInsurance | $ 14,531 us-gaap_CashSurrenderValueOfLifeInsurance
Banking Premises [Member] |  |
Premises and equipment [Line Items] |  |
Methods | Straight-Line and Accelerated |
Banking Premises [Member] | Minimum [Member] |  |
Premises and equipment [Line Items] |  |
Useful lives of the assets | 15 years |
Banking Premises [Member] | Maximum [Member] |  |
Premises and equipment [Line Items] |  |
Useful lives of the assets | 40 years |
Furniture and Equipment [Member] |  |
Premises and equipment [Line Items] |  |
Methods | Straight-Line and Accelerated |
Furniture and Equipment [Member] | Minimum [Member] |  |
Premises and equipment [Line Items] |  |
Useful lives of the assets | 5 years |
Furniture and Equipment [Member] | Maximum [Member] |  |
Premises and equipment [Line Items] |  |
Useful lives of the assets | 10 years |

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- Definition Discounted percentage to account for selling and marketing costs. + References No definition available. + Details
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- Definition Percentage of loan portfolio concentrated in loans secured by real estate. + References No definition available. + Details
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- Definition Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 4 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765 + Details
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- Definition Description of the methodology for computing depreciation for classes of depreciable assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 + Details
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- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
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