Loans (Composition Of Loan Portfolio By Class Of Loan) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 126,102		$ 169,690	$ 126,102		$ 169,690	$ 137,339
Loan balance	4,510,716			4,510,716			4,450,322
Accrued interest receivable	14,121			14,121			13,587
Recorded Investment	4,524,837			4,524,837			4,463,909
Impaired Financing Receivable, Average Recorded Investment	127,057		174,963	130,405		177,738
Impaired Financing Receivable, Interest Income, Cash Basis Method	645		817	1,379		1,420
Commercial, Financial And Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	20,154		41,591	20,154		41,591
Recorded Investment	809,893			809,893			826,903
Impaired Financing Receivable, Average Recorded Investment	21,148		42,056	21,252		41,218
Impaired Financing Receivable, Interest Income, Cash Basis Method	82		205	210		310
Construction Real Estate - Vision/SEPH Commercial Land And Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	9,074		17,272	9,074		17,272
Loan balance	10,217	[1]		10,217	[1]		15,105	[1]
Accrued interest receivable	21	[1]		21	[1]		37	[1]
Recorded Investment	10,238	[1]		10,238	[1]		15,142	[1]
Impaired Financing Receivable, Average Recorded Investment	9,532		18,412	10,854		20,302
Impaired Financing Receivable, Interest Income, Cash Basis Method
Construction Real Estate - Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	18,535		29,562	18,535		29,562
Loan balance	113,443			113,443			115,473
Accrued interest receivable	281			281			331
Recorded Investment	113,724			113,724			115,804
Impaired Financing Receivable, Average Recorded Investment	19,390		31,428	20,103		28,899
Impaired Financing Receivable, Interest Income, Cash Basis Method	192		199	412		450
Construction Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	24,570			24,570			26,373
Accrued interest receivable	75			75			81
Recorded Investment	24,645			24,645			26,454
Construction Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	7,638			7,638			8,577
Accrued interest receivable	28			28			33
Recorded Investment	7,666			7,666			8,610
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	35,412		37,277	35,412		37,277
Loan balance	400,540			400,540			392,203
Accrued interest receivable	1,008			1,008			959
Recorded Investment	401,548			401,548			393,162
Impaired Financing Receivable, Average Recorded Investment	36,141		40,359	35,897		41,541
Impaired Financing Receivable, Interest Income, Cash Basis Method	112		125	242		165
Residential Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	1,091,874			1,091,874			1,064,787
Accrued interest receivable	2,028			2,028			1,399
Recorded Investment	1,093,902			1,093,902			1,066,186
Residential Real Estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	209,902			209,902			212,905
Accrued interest receivable	841			841			892
Recorded Investment	210,743			210,743			213,797
Residential Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	38,446			38,446			43,750
Accrued interest receivable	144			144			176
Recorded Investment	38,590			38,590			43,926
Commercial, Financial And Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	806,709	[1]		806,709	[1]		823,927	[1]
Accrued interest receivable	3,184	[1]		3,184	[1]		2,976	[1]
Recorded Investment	809,893	[1]		809,893	[1]		826,903	[1]
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	42,128		43,969	42,128		43,969
Loan balance	1,113,251	[1]		1,113,251	[1]		1,092,164	[1]
Accrued interest receivable	3,689	[1]		3,689	[1]		3,839	[1]
Recorded Investment	1,116,940	[1]		1,116,940	[1]		1,096,003	[1]
Impaired Financing Receivable, Average Recorded Investment	40,047		42,689	41,840		45,758
Impaired Financing Receivable, Interest Income, Cash Basis Method	259		287	515		494
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	799		19	799		19
Loan balance	690,892			690,892			651,930
Accrued interest receivable	2,794			2,794			2,835
Recorded Investment	693,686			693,686			654,765
Impaired Financing Receivable, Average Recorded Investment	799		19	459		20
Impaired Financing Receivable, Interest Income, Cash Basis Method			1			1
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	3,234			3,234			3,128
Accrued interest receivable	28			28			29
Recorded Investment	$ 3,262			$ 3,262			$ 3,157

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