Loans and Asset Quality Information (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
All loans (non-covered and covered):
Amount of loans	$ 2,439,593	$ 2,429,106	$ 2,431,253
Percentage of Loans	100.00%	100.00%	100.00%
Unamortized net deferred loan costs	1,478	1,280	1,295
Loans, total	2,441,071	2,430,386	2,432,548
Commercial, financial and agricultural
All loans (non-covered and covered):
Amount of loans	161,846	162,099	161,300
Percentage of Loans	7.00%	7.00%	7.00%
Real Estate construction, land development & other land loans
All loans (non-covered and covered):
Amount of loans	329,375	363,079	370,735
Percentage of Loans	13.00%	15.00%	15.00%
Real estate mortgage residential (1-4 family) first mortgages
All loans (non-covered and covered):
Amount of loans	823,069	805,542	803,688
Percentage of Loans	34.00%	33.00%	33.00%
Real estate mortgage home equity loans/lines of credit
All loans (non-covered and covered):
Amount of loans	243,556	256,509	258,653
Percentage of Loans	10.00%	11.00%	11.00%
Real estate mortgage commercial and other
All loans (non-covered and covered):
Amount of loans	807,914	762,895	756,568
Percentage of Loans	33.00%	31.00%	31.00%
Installment loans to individual
All loans (non-covered and covered):
Amount of loans	$ 73,833	$ 78,982	$ 80,309
Percentage of Loans	3.00%	3.00%	3.00%