Loans and Asset Quality Information (Summary of Major Categories of Total Loans Outstanding) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
All loans (non-covered and covered):
Amount of loans	$ 2,394,616	$ 2,395,228	$ 2,446,518
Percentage of Loans	100.00%	100.00%	100.00%
Unamortized net deferred loan costs	783	946	759
Loans, total	2,395,399	2,396,174	2,447,277
Commercial, financial and agricultural [Member]
All loans (non-covered and covered):
Amount of loans	176,013	160,878	179,363
Percentage of Loans	7.00%	7.00%	7.00%
Real Estate construction, land development and other land loans [Member]
All loans (non-covered and covered):
Amount of loans	285,319	288,148	296,141
Percentage of Loans	12.00%	12.00%	12.00%
Real estate mortgage residential (1-4 family) first mortgages [Member]
All loans (non-covered and covered):
Amount of loans	776,313	789,871	829,671
Percentage of Loans	33.00%	33.00%	34.00%
Real estate mortgage home equity loans/lines of credit [Member]
All loans (non-covered and covered):
Amount of loans	223,679	223,500	229,167
Percentage of Loans	9.00%	9.00%	9.00%
Real estate mortgage commercial and other [Member]
All loans (non-covered and covered):
Amount of loans	885,282	882,127	857,327
Percentage of Loans	37.00%	37.00%	35.00%
Installment loans to individual [Member]
All loans (non-covered and covered):
Amount of loans	$ 48,010	$ 50,704	$ 54,849
Percentage of Loans	2.00%	2.00%	3.00%