XML 58 R47.htm IDEA: XBRL DOCUMENT
v3.20.2

Allowance for Loan Losses (Details Textual) | Sep. 30, 2020 USD ($)
--- | ---
Receivables [Abstract] |
Outstanding balance of high risk loans, minimum | $ 250,000

X
- Definition Minimum loan balance for reviewing. + References No definition available. + Details
Name: | cban_LoanBalanceForReviewingHighRiskLoansMinimum
Namespace Prefix: | cban_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_ReceivablesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration