Deposits (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Deposits [Abstract]
Aggregate amount of overdrawn deposit accounts reclassified as loan balances	$ 400,552	$ 389,331
Components of interest-bearing deposits [Abstract]
Interest-Bearing Demand	357,290,975	314,030,843
Savings	54,094,617	48,777,743
Time, $100,000 and Over	220,672,794	211,244,750
Other Time	240,210,393	281,665,013
Total Interest bearing Deposits	872,268,779	855,718,349
Brokered deposits balances	26,579,934	28,229,608
CDARS balances	26,579,934	28,229,608
Brokered deposits less the reciprocal deposits	0	0
Certificates of deposits, $100,000 or more	143,388,694	161,530,500
Scheduled maturities of certificates of deposits [Abstract]
2014	322,971,106
2015	69,000,752
2016	37,944,799
2017	12,974,997
2018 and Thereafter	17,991,533
Total	$ 460,883,187

Refers to the remaining balance amount of brokered deposits less the reciprocal deposits as of balance sheet date.

No definition available.

Name:	cban_BrokeredDepositsLessReciprocalDeposits
Namespace Prefix:	cban_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Refers to Certificate of Deposits Account Registry Service reciprocal deposits (CDARS) in which customers placed core deposits into the CDARS program for FDIC insurance coverage.

+ References

No definition available.

+ Details

Name:	cban_CertificateOfDepositsAccountRegistryServiceReciprocalDepositsBalances
Namespace Prefix:	cban_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate amount of domestic and foreign certificates of deposit liabilities in denominations of $100,000 or more.

+ References

No definition available.

+ Details

Name:	cban_CertificatesOfDeposits100000OrMore
Namespace Prefix:	cban_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Refers to the aggregate amount of overdrawn deposit accounts reclassified as loan balances as of balance sheet date.

+ References

No definition available.

+ Details

Name:	cban_TotalAmountOfOverdrawnDeposit
Namespace Prefix:	cban_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of money in accounts that may bear interest and that the depositor is entitled to withdraw at any time without prior notice.

+ References

+ Details

Name:	us-gaap_DemandDepositAccounts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DepositsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DepositsByTypeAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.12)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-DEP

-Paragraph 6

-IssueDate 2006-05-01

-Chapter 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_DepositsSavingsDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate of all domestic and foreign interest-bearing deposit liabilities.

+ References

+ Details

Name:	us-gaap_InterestBearingDepositLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of interest-bearing domestic third-party deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities.

+ References

+ Details

Name:	us-gaap_InterestBearingDomesticDepositBrokered
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposits maturing after the fifth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-DEP

-Paragraph 45

-Subparagraph a

-IssueDate 2006-05-01

-Chapter 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_TimeDepositMaturitiesAfterYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposits maturing in the fourth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposits maturing in the next fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearOne
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposits maturing in the third fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposits maturing in the second fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

Name:	us-gaap_TimeDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate amount of domestic and foreign time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 405

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6479006&loc=d3e64164-112818

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Industry Guide

-Number 3

-Section V

-Paragraph A

-Subparagraph 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-DEP

-Paragraph 42

-Subparagraph a

-IssueDate 2008-05-01

-Chapter 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 01-6

-Paragraph 14

-Subparagraph e

-Clause 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_TimeDeposits100000OrMore
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_TimeDepositsByMaturityAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate amount of domestic or foreign time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to less than $100,000.

+ References

No definition available.

+ Details

Name:	us-gaap_TimeDepositsLessThan100000
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant