Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended
		Jan. 31, 2015	Jul. 31, 2011	Mar. 31, 2017	Mar. 31, 2016
Goodwill
Beginning Balance	[1]			$ 43,872
Additions				0
Amortization				0
Impairment				0
Ending Balance				43,872	$ 43,872
Intangibles
Beginning Balance				1,719
Additions				0
Amortization				(165)	$ (288)
Impairment				0
Ending Balance				$ 1,554
MidCarolina
Acquired Finite-Lived Intangible Assets [Line Items]
Core deposit intangible			$ 6,556
Amortization period of intangible			108 months
MainStreet BankShares, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Core deposit intangible		$ 1,839
Amortization period of intangible		120 months

[1] Derived from audited consolidated financial statements.