Merger - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2014 FCBC Financial Corp [Member]	Sep. 30, 2014 TCNB Financial Corp [Member]	Jun. 30, 2014 TCNB Financial Corp [Member]
Business Combinations [Line Items]
Amount payable in cash	$ 23.50
Common shares outstanding		733,000
Other common shares agreed to be cashed out		3,500
Aggregate cash consideration to be paid		$ 17.2
Total consolidated assets			105
Total loan			75
Total deposits			$ 93