Premises and Equipment, net - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Branch Office	Dec. 31, 2011 Branch	Dec. 31, 2010	Mar. 30, 2012 Branch
Property, Plant and Equipment [Line Items]
Number of commercial and consumer banking branches	25
Number of leased branches	5
Number of owned branches	20
Number of Limited service offices	6
Reduction in branch network		4
Number of branches to be consolidated				2
Number of branches to be sold	2
Leasehold improvements amount				$ 223
Depreciation expense	2,529	2,452	2,581
Land and Building [Member]
Property, Plant and Equipment [Line Items]
Amount received on disposal of asset	408
Furniture And Equipment [Member]
Property, Plant and Equipment [Line Items]
Amount received on disposal of asset	$ 175
Greenville County [Member]
Property, Plant and Equipment [Line Items]
Number of leased branches	1