Loans (Composition Of Loan Portfolio By Class Of Loan) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Loan balance	$ 4,324,383		$ 4,317,099
Accrued interest receivable	14,200		14,684
Total recorded investment	4,338,583		4,331,783
Commercial, Financial And Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	752,392	[1]	743,797	[1]
Accrued interest receivable	3,439	[1]	3,121	[1]
Total recorded investment	755,831	[1]	746,918	[1]
Construction Real Estate - Vision/SE LLC Commercial Land And Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	26,081	[1]	31,603	[1]
Accrued interest receivable	39	[1]	31	[1]
Total recorded investment	26,120	[1]	31,634	[1]
Construction Real Estate - Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	148,922		156,053
Accrued interest receivable	425		394
Total recorded investment	149,347		156,447
Construction Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	19,628		20,039
Accrued interest receivable	65		64
Total recorded investment	19,693		20,103
Construction Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	9,184		9,851
Accrued interest receivable	44		61
Total recorded investment	9,228		9,912
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	392,552		395,824
Accrued interest receivable	1,120		1,105
Total recorded investment	393,672		396,929
Residential Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	1,004,957		953,758
Accrued interest receivable	1,540		1,522
Total recorded investment	1,006,497		955,280
Residential Real Estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	221,780		227,682
Accrued interest receivable	884		942
Total recorded investment	222,664		228,624
Residential Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	48,410		51,354
Accrued interest receivable	217		236
Total recorded investment	48,627		51,590
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	1,088,348	[1]	1,108,574	[1]
Accrued interest receivable	3,795	[1]	4,235	[1]
Total recorded investment	1,092,143	[1]	1,112,809	[1]
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	610,180		616,505
Accrued interest receivable	2,580		2,930
Total recorded investment	612,760		619,435
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	1,949		2,059
Accrued interest receivable	52		43
Total recorded investment	$ 2,001		$ 2,102

[1] Included within commercial, financial and agricultural loans, commercial real estate loans, and Vision/SE LLC commercial land and development loans is an immaterial amount of consumer loans that are not broken out by class.