Goodwill And Other Intangible Assets (Narrative) (Details) - USD ($)			12 Months Ended
	Apr. 01, 2017	Oct. 01, 2016	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Acquired goodwill, net			$ 4,252,000
Finite-lived intangible assets, net			12,241,000	$ 2,663,000
Finite-Lived Core Deposits, Gross			11,270,000	1,560,000
Finite-Lived Customer Relationships, Gross			$ 900,000,000	$ 1,100,000
HIghland County Bankshares Inc and Subsidiary First and Citizens Bank [Member]
Business Acquisition [Line Items]
Intangible assets acquired in business combination		$ 1,600,000
Acquired goodwill, net		$ 4,800,000
First Century Bankshares, Inc [Member]
Business Acquisition [Line Items]
Intangible assets acquired in business combination	$ 10,900,000
Acquired goodwill, net	$ 4,300,000