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Note 2 - Merger - Fair Value of the Assets Acquired and Liabilities Assumed in the FWVB Merger (Details) - USD ($) $ in Thousands	Apr. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Liabilities Assumed:
Goodwill Recognized		$ 27,071	$ 4,953
First West Virginia Bancorp [Member]
Cash Paid for Redemption of FWVB Common Stock	$ 9,801
CB Financial Common Stock Issued in Exchange for FWVB Common Stock	41,527
Total Consideration Paid	51,328
Cash and Cash Equivalents	30,433
Net Loans	95,456
Investment Securities	187,628
Premises and Equipment	3,712
Bank Owned Life Insurance	4,212
Core Deposit Intangible	9,127
Deferred Tax Assets	2,497
Other Assets	3,030
Total Assets Acquired	336,095
Liabilities Assumed:
Deposits	281,620
Borrowings	22,329
Other Liabilities	2,935
Total Liabilities Assumed	306,884
Total Identifiable Net Assets	29,211
Goodwill Recognized	$ 22,117