Minimum percentage of the total merger consideration that will be paid in company stock.

No definition available.

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Namespace Prefix:	cban_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of shares of the acquiring entity into which the shares of the acquired entity may be converted pursuant to a definitive agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	cban_
Data Type:	xbrli:sharesItemType
Balance Type:	na
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- Definition

Percentage of shares being acquired that will receive cash consideration.

+ References

No definition available.

+ Details

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Namespace Prefix:	cban_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of shares being acquired that will receive stock consideration.

+ References

No definition available.

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Namespace Prefix:	cban_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of loans receivable recognized as of the acquisition date.

+ References

No definition available.

+ Details

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

- Definition

The discount percentage related to loans and leases receivables.

+ References

No definition available.

+ Details

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Namespace Prefix:	cban_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of equity interests issued or issuable to acquire entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionSharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(3)
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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)
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Balance Type:	credit
Period Type:	duration

- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Subparagraph (h)(2)
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-SubTopic 10
-Section 50
-Paragraph 2
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Balance Type:	credit
Period Type:	duration

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
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-SubTopic 30
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Period Type:	duration

- Definition

Fair value at acquisition of acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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Balance Type:	debit
Period Type:	instant

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Publisher FASB
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-SubTopic 20
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Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

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-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Note 2 - Business Acquisitions (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended
	May 01, 2019	Oct. 22, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Payments to Acquire Businesses, Gross					$ 467
Goodwill, Ending Balance			$ 16,134		16,134		$ 202
Planters First Bank [Member]
Payments to Acquire Businesses, Gross		$ 10,200
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual			58		129
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual			(85)		(159)
Goodwill, Ending Balance		202
Business Acquisition, Goodwill, Expected Tax Deductible Amount		$ 202
LBC Bancshares, Inc [Member]
Payments to Acquire Businesses, Gross	$ 15,312
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual			1,770		1,770
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual			501		501
Goodwill, Ending Balance	$ 15,390
Business Acquisition, Share Price	$ 23.50
Business Acquisition, Number of Shares of Acquiring Entity for Each Share of Acquired Entity	1.3239
Business Acquistion, Percentage of Shares Receiving Stock Consideration	55.00%
Business Acquistion, Percentage of Shares Receiving Cash Consideration	45.00%
Business Acquisition, Minimum Percentage of Merger Consideration Paid in Stock	50.00%
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	1,054,029
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 18,709
Business Acquisition, Pro Forma Revenue				$ 2,350		4,610
Business Acquisition, Pro Forma Net Income (Loss)				$ 610		$ 1,150
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Receivable	130,568		130,570		130,570
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums, Total			$ 2,170		$ 2,170
Loans and Leases Receivable, Discount Percentage			1.63%		1.63%
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	176		$ 176		$ 176
Business Combination, Consideration Transferred, Total	34,021
PFB Mortgage [Member]
Payments to Acquire Businesses, Gross	833
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual			228		228
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual			211		211
Goodwill, Ending Balance	541		541		541
Business Acquisition, Goodwill, Expected Tax Deductible Amount			$ 541		$ 541
Business Combination, Consideration Transferred, Total	$ 833