XML 115 R99.htm IDEA: XBRL DOCUMENT
v3.19.1

Note 16 - Commitments and Contingencies (Details Textual) | 12 Months Ended
--- | ---
Dec. 31, 2018
Expiration Period Of Letter Of Credit Issued | 1 year

X
- Definition Refers to the expiration dates of letter of credit issued measured in years. + References No definition available. + Details
Name: | cban_ExpirationPeriodOfLetterOfCreditIssued
Namespace Prefix: | cban_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration