FAIR VALUE OF FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($)	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair value input, discounted amount	10.00%
Amount in transfers between levels	$ 15,600,000	$ 0

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Amount Of Transfers In and Out of Levels

No definition available.

Name:	cban_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetNumberOfTransfersOutOfLevel3
Namespace Prefix:	cban_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration