Business Combinations - Assets and Liabilities Acquired (Details) - USD ($)		12 Months Ended
	May 01, 2019	Dec. 31, 2020	May 01, 2020	Dec. 31, 2019
Purchase Price Consideration:
Cash Consideration Paid		$ 0		$ 467,000
Liabilities Assumed at Fair Value:
Amount of Goodwill Resulting from Acquisition		$ 15,992,000		$ 16,477,000
LBC Bancshares, Inc
Purchase Price Consideration:
Shares of CBAN Common Stock Issued to LBC Shareholders as of May 1, 2019 (in shares)	1,053,875
Market Price of CBAN Common Stock on May 1, 2019 (in dollars per share)	$ 17.29
Estimated Fair Value of CBAN Common Stock Issued	$ 18,221,000
Cash Consideration Paid	15,315,000
Total Consideration	33,536,000
Subsequent Adjustments
Shares of CBAN Common Stock Issued to LBC Shareholders as of May 1, 2019 (in shares)			1,053,875
Market Price of CBAN Common Stock on May 1, 2019 (in dollars per share)			$ (0.46)
Estimated Fair Value of CBAN Common Stock Issued			$ (485,000)
Total Consideration			(485,000)
Amount of Goodwill Resulting from Acquisition			$ (485,000)
Assets acquired at fair value:
Cash and Cash Equivalents	15,678,000
Investments Securities Available for Sale	49,172,000
Investments Securities Held to Maturity	1,766,000
Restricted Investments	479,000
Loans	130,568,000
Premises and Equipment	3,009,000
Core Deposit Intangible	3,100,000
Other Real Owned	243,000
Prepaid and Other Assets	6,143,000
Total Fair Value of Assets Acquired	210,158,000
Liabilities Assumed at Fair Value:
Deposits	(189,896,000)
FHLB Advances	(1,000,000)
Payables and Other Liabilities	(975,000)
Total Fair Value of Liabilities Assumed	(191,871,000)
Net Assets Acquired at Fair Value:	18,287,000
Amount of Goodwill Resulting from Acquisition	$ 15,249,000
LBC Bancshares, Inc | Previously Reported
Purchase Price Consideration:
Shares of CBAN Common Stock Issued to LBC Shareholders as of May 1, 2019 (in shares)	1,053,875
Market Price of CBAN Common Stock on May 1, 2019 (in dollars per share)	$ 17.75
Estimated Fair Value of CBAN Common Stock Issued	$ 18,706,000
Cash Consideration Paid	15,315,000
Total Consideration	34,021,000
Assets acquired at fair value:
Cash and Cash Equivalents	15,678,000
Investments Securities Available for Sale	49,172,000
Investments Securities Held to Maturity	1,766,000
Restricted Investments	479,000
Loans	130,568,000
Premises and Equipment	3,009,000
Core Deposit Intangible	3,100,000
Other Real Owned	243,000
Prepaid and Other Assets	6,143,000
Total Fair Value of Assets Acquired	210,158,000
Liabilities Assumed at Fair Value:
Deposits	(189,896,000)
FHLB Advances	(1,000,000)
Payables and Other Liabilities	(975,000)
Total Fair Value of Liabilities Assumed	(191,871,000)
Net Assets Acquired at Fair Value:	18,287,000
Amount of Goodwill Resulting from Acquisition	15,734,000
PFB Mortgage
Purchase Price Consideration:
Cash Consideration Paid	833,000
Total Consideration	833,000
Assets acquired at fair value:
Premises and Equipment	78,000
Premium on Loan Commitments	209,000
Other Assets	5,000
Total Fair Value of Assets Acquired	292,000
Liabilities Assumed at Fair Value:
Total Fair Value of Liabilities Assumed	0
Net Assets Acquired at Fair Value:	292,000
Amount of Goodwill Resulting from Acquisition	$ 541,000