Loans (Composition Of Loan Portfolio By Class Of Loan) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loan balance	$ 4,443,523		$ 4,450,322
Accrued interest receivable	14,541		13,587
Recorded Investment	4,458,064		4,463,909
Construction Real Estate - Vision/SEPH Commercial Land And Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	12,285	[1]	15,105	[1]
Accrued interest receivable	26	[1]	37	[1]
Recorded Investment	12,311	[1]	15,142	[1]
Construction Real Estate - Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	115,589		115,473
Accrued interest receivable	285		331
Recorded Investment	115,874		115,804
Construction Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	24,522		26,373
Accrued interest receivable	74		81
Recorded Investment	24,596		26,454
Construction Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	8,055		8,577
Accrued interest receivable	31		33
Recorded Investment	8,086		8,610
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	400,400		392,203
Accrued interest receivable	1,008		959
Recorded Investment	401,408		393,162
Residential Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	1,064,006		1,064,787
Accrued interest receivable	1,884		1,399
Recorded Investment	1,065,890		1,066,186
Residential Real Estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	210,981		212,905
Accrued interest receivable	861		892
Recorded Investment	211,842		213,797
Residential Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	41,204		43,750
Accrued interest receivable	163		176
Recorded Investment	41,367		43,926
Commercial, Financial And Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	796,449	[1]	823,927	[1]
Accrued interest receivable	3,431	[1]	2,976	[1]
Recorded Investment	799,880	[1]	826,903	[1]
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	1,108,915	[1]	1,092,164	[1]
Accrued interest receivable	4,084	[1]	3,839	[1]
Recorded Investment	1,112,999	[1]	1,096,003	[1]
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	657,697		651,930
Accrued interest receivable	2,643		2,835
Recorded Investment	660,340		654,765
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	3,420		3,128
Accrued interest receivable	51		29
Recorded Investment	$ 3,471		$ 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.