Loans and Asset Quality Information (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
All loans (non-covered and covered):
Amount of loans	$ 2,429,694	$ 2,375,133	$ 2,436,425
Percentage of Loans	100.00%	100.00%	100.00%
Unamortized net deferred loan costs	1,168	1,324	1,376
Loans, total	2,430,862	2,376,457	2,437,801
Commercial, financial and agricultural
All loans (non-covered and covered):
Amount of loans	164,767	160,790	163,761
Percentage of Loans	7.00%	7.00%	7.00%
Real Estate construction, land development and other land loans
All loans (non-covered and covered):
Amount of loans	297,390	298,458	343,620
Percentage of Loans	12.00%	13.00%	14.00%
Real estate mortgage residential (1-4 family) first mortgages
All loans (non-covered and covered):
Amount of loans	832,761	815,281	815,605
Percentage of Loans	34.00%	34.00%	34.00%
Real estate mortgage home equity loans/lines of credit
All loans (non-covered and covered):
Amount of loans	231,446	238,925	250,627
Percentage of Loans	10.00%	10.00%	10.00%
Real estate mortgage commercial and other
All loans (non-covered and covered):
Amount of loans	834,554	789,746	789,290
Percentage of Loans	34.00%	33.00%	32.00%
Installment loans to individual
All loans (non-covered and covered):
Amount of loans	$ 68,776	$ 71,933	$ 73,522
Percentage of Loans	3.00%	3.00%	3.00%