Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended		6 Months Ended
		Jan. 31, 2015	Jul. 31, 2011	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Core deposit intangible				$ 0	$ 1,839	$ 0	$ 1,839
Goodwill
December 31, 2015	[1]					43,872
Additions						0
Amortization						0
Impairment						0
June 30, 2016				43,872	44,210	43,872	44,210
Intangibles
December 31, 2015						2,683
Additions						0
Amortization				(288)	$ (300)	(576)	$ (601)
Impairment						0
June 30, 2016				$ 2,107		$ 2,107
MidCarolina [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Core deposit intangible			$ 6,556
Amortization period of intangible			108 months
MainStreet BankShares, Inc. [Member]
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.