Summary of Organization - Additional Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Organization [Line Items]
Entity Incorporation, Date Of Incorporation					Jun. 23, 1995
Entity Incorporation, State Country Name					Hattiesburg, Mississippi
Assets	$ 951,895				$ 951,895		$ 721,386
Loans, including Loans held for sale	572,513				572,513		413,698
Deposits	813,965				813,965		596,627
Stockholders' equity	83,760			65,372	83,760	65,372	65,886	60,425
Net income	1,104			872	3,141	2,880
Net Income applicable to common stockholders	$ 998			$ 766	$ 2,823	$ 2,562
Dividends per share common	$ 0.0375	$ 0.0375	$ 0.0375	$ 0.0375	$ 0.1125	$ 0.1125