Loans (Aging Of Recorded Investment In Past Due Loans) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	$ 27,488		$ 37,517
Past due nonaccrual loans and loans past due 90 days or more and accruing	110,371	[1],[2]	94,663	[1]
Total loans past due	137,859		132,180
Total current	4,200,724		4,199,603
Total recorded investment	4,338,583		4,331,783
Loans past due 90 days or more and accruing	2,339		3,561
Commercial, Financial And Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	3,935		3,106
Past due nonaccrual loans and loans past due 90 days or more and accruing	28,225	[1],[2]	11,308	[1]
Total loans past due	32,160		14,414
Total current	723,671		732,504
Total recorded investment	755,831	[3]	746,918	[3]
Loans past due 90 days or more and accruing	12
Construction Real Estate - Vision/SE LLC Commercial Land And Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	337
Past due nonaccrual loans and loans past due 90 days or more and accruing	16,587	[1],[2]	19,235	[1]
Total loans past due	16,924		19,235
Total current	9,196		12,399
Total recorded investment	26,120	[3]	31,634	[3]
Construction Real Estate - Remaining Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days			99
Past due nonaccrual loans and loans past due 90 days or more and accruing	7,702	[1],[2]	7,839	[1]
Total loans past due	7,702		7,938
Total current	141,645		148,509
Total recorded investment	149,347		156,447
Construction Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	173		76
Total loans past due	173		76
Total current	19,520		20,027
Total recorded investment	19,693		20,103
Construction Real Estate - Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	61		421
Past due nonaccrual loans and loans past due 90 days or more and accruing	75	[1],[2]	8	[1]
Total loans past due	136		429
Total current	9,092		9,483
Total recorded investment	9,228		9,912
Loans past due 90 days or more and accruing	16
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	502		1,545
Past due nonaccrual loans and loans past due 90 days or more and accruing	13,261	[1],[2]	10,097	[1]
Total loans past due	13,763		11,642
Total current	379,909		385,287
Total recorded investment	393,672		396,929
Residential Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	13,174		15,879
Past due nonaccrual loans and loans past due 90 days or more and accruing	18,840	[1],[2]	20,614	[1]
Total loans past due	32,014		36,493
Total current	974,483		918,787
Total recorded investment	1,006,497		955,280
Loans past due 90 days or more and accruing	1,523		2,610
Residential Real Estate - HELOC [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	331		1,015
Past due nonaccrual loans and loans past due 90 days or more and accruing	297	[1],[2]	436	[1]
Total loans past due	628		1,451
Total current	222,036		227,173
Total recorded investment	222,664		228,624
Residential Real Estate - Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	611		1,549
Past due nonaccrual loans and loans past due 90 days or more and accruing	510	[1],[2]	1,136	[1]
Total loans past due	1,121		2,685
Total current	47,506		48,905
Total recorded investment	48,627		51,590
Loans past due 90 days or more and accruing	221		58
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	1,062		2,632
Past due nonaccrual loans and loans past due 90 days or more and accruing	23,067	[1],[2]	21,798	[1]
Total loans past due	24,129		24,430
Total current	1,068,014		1,088,379
Total recorded investment	1,092,143	[3]	1,112,809	[3]
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days	7,302		11,195
Past due nonaccrual loans and loans past due 90 days or more and accruing	1,807	[1],[2]	2,192	[1]
Total loans past due	9,109		13,387
Total current	603,651		606,048
Total recorded investment	612,760		619,435
Loans past due 90 days or more and accruing	567		893
Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total current	2,001		2,102
Total recorded investment	$ 2,001		$ 2,102

[1] Includes $3.6 million of loans past due 90 days or more and accruing.

[2] Includes $2.4 million of loans past due 90 days or more and accruing.

[3] 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.