Acquired Credit Impaired Loans, Major Classifications of Acquired Credit Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	$ 1,162,325	$ 849,060
Total	1,158,309	845,657
Financial Asset Acquired with Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	12,128	7,482
Financial Asset Acquired with Credit Deterioration [Member] | Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	1,136	1,008
Financial Asset Acquired with Credit Deterioration [Member] | Commercial, secured by real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	7,352	4,048
Financial Asset Acquired with Credit Deterioration [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	3,261	2,024
Financial Asset Acquired with Credit Deterioration [Member] | Other loans, including deposit overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	379	402
First Capital Bancshares, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,758	1,815
First Capital Bancshares, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	14	20
First Capital Bancshares, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial, secured by real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	825	848
First Capital Bancshares, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	919	947
First Capital Bancshares, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Other loans, including deposit overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	0	0
Eaton National Bank & Trust Co. [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,452	3,981
Eaton National Bank & Trust Co. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	677	988
Eaton National Bank & Trust Co. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial, secured by real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	1,588	1,699
Eaton National Bank & Trust Co. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	808	892
Eaton National Bank & Trust Co. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Other loans, including deposit overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	379	402
BNB Bancorp, Inc [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,573	1,686
BNB Bancorp, Inc [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	0	0
BNB Bancorp, Inc [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial, secured by real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	1,412	1,501
BNB Bancorp, Inc [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	161	185
BNB Bancorp, Inc [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Other loans, including deposit overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	0	$ 0
Columbus First Bancorp, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	5,345
Columbus First Bancorp, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	445
Columbus First Bancorp, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Commercial, secured by real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	3,527
Columbus First Bancorp, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	1,373
Columbus First Bancorp, Inc. [Member] | Financial Asset Acquired with Credit Deterioration [Member] | Other loans, including deposit overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	$ 0