Loans and Asset Quality Information (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
All loans (non-covered and covered):
Amount of loans	$ 2,375,133	$ 2,429,106
Percentage of Loans	100.00%	100.00%
Unamortized net deferred loan costs	1,324	1,280
Loans, total	2,376,457	2,430,386
Commercial, financial and agricultural
All loans (non-covered and covered):
Amount of loans	160,790	162,099
Percentage of Loans	7.00%	7.00%
Real Estate construction, land development and other land loans
All loans (non-covered and covered):
Amount of loans	298,458	363,079
Percentage of Loans	13.00%	15.00%
Real estate mortgage residential (1-4 family) first mortgages
All loans (non-covered and covered):
Amount of loans	815,281	805,542
Percentage of Loans	34.00%	33.00%
Real estate mortgage home equity loans/lines of credit
All loans (non-covered and covered):
Amount of loans	238,925	256,509
Percentage of Loans	10.00%	11.00%
Real estate mortgage commercial and other
All loans (non-covered and covered):
Amount of loans	789,746	762,895
Percentage of Loans	33.00%	31.00%
Installment loans to individual
All loans (non-covered and covered):
Amount of loans	$ 71,933	$ 78,982
Percentage of Loans	3.00%	3.00%