Loans (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Summary of net loans, by loan type
Net loans	$ 5,256,183	$ 5,410,003
Commercial, financial and agricultural
Summary of net loans, by loan type
Net loans	1,297,647	1,473,471
Real estate - mortgage
Summary of net loans, by loan type
Net loans	943,978	948,982
Commercial real estate: other construction and land development
Summary of net loans, by loan type
Net loans	2,658,034	2,615,878
Consumer
Summary of net loans, by loan type
Net loans	108,113	126,047
Foreign
Summary of net loans, by loan type
Net loans	$ 248,411	$ 245,625