Trust Preferred Capital Notes, Debt Items (Details) (USD $) In Thousands, unless otherwise specified								3 Months Ended		3 Months Ended		3 Months Ended
	Mar. 31, 2014 MidCarolina I [Member]	Jul. 01, 2011 MidCarolina I [Member]	Mar. 31, 2014 MidCarolina II [Member]	Jul. 01, 2011 MidCarolina II [Member]	Jul. 01, 2011 MidCarolina Trust [Member]	Mar. 31, 2014 Junior Subordinated Debt Securities [Member]	Dec. 31, 2013 Junior Subordinated Debt Securities [Member]	Mar. 31, 2014 Junior Subordinated Debt Securities [Member] AMNB Trust I [Member]	Dec. 31, 2013 Junior Subordinated Debt Securities [Member] AMNB Trust I [Member]	Mar. 31, 2014 Junior Subordinated Debt Securities [Member] MidCarolina I [Member]	Dec. 31, 2013 Junior Subordinated Debt Securities [Member] MidCarolina I [Member]	Mar. 31, 2014 Junior Subordinated Debt Securities [Member] MidCarolina II [Member]	Dec. 31, 2013 Junior Subordinated Debt Securities [Member] MidCarolina II [Member]
Debt Instrument [Line Items]
Date Issued								Apr. 07, 2006		Oct. 29, 2002		Dec. 03, 2003
Interest Rate								Libor plus 1.35%		Libor plus 3.45%		Libor plus 2.95%
Variable Rate Basis								Libor plus		Libor plus		Libor plus
Basis Spread on Variable Rate (in hundredths)								1.35%		3.45%		2.95%
Maturity Date								Jun. 30, 2036		Nov. 07, 2032		Oct. 07, 2033
Principal Amount					$ 8,764	$ 27,444	$ 27,419	$ 20,619	$ 20,619	$ 4,111	$ 4,098	$ 2,714	$ 2,702
Valuation allowance associated with junior subordinated debenture	$ 1,044	$ 895	$ 1,197	$ 1,021