Allowance For Loan Losses (Composition Of The Allowance For Loan Losses) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Jun. 30, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
General reserves as a percent of performing loans	1.09%		1.09%
Allowance for loan losses individually evaluated for impairment	$ 9,297			$ 8,276
Allowance for loan losses collectively evaluated for impairment	48,597			47,261
Total ending allowance balance	57,894			55,537
Loans individually evaluated for impairment	118,225			137,238
Loans collectively evaluated for impairment	4,455,312			4,313,084
Total ending loan balance, net of accrued interest receivable	4,573,537			4,450,322
Allowance for loan losses as a percentage of loan balance individually evaluated for impairment	7.86%			6.03%
Allowance for loan losses as a percentage of loan balance collectively evaluated for impairment	1.09%			1.10%
Total ending allowance for loan losses balance as a percentage of loan balance	1.27%			1.25%
Recorded investment	118,251			137,339
Recorded investment collectively evaluated for impairment	4,469,044			4,326,570
Recorded Investment	4,587,295			4,463,909
Commercial Financial And Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses individually evaluated for impairment	1,728			3,180
Allowance for loan losses collectively evaluated for impairment	12,323			12,455
Total ending allowance balance	14,051			15,635
Loans individually evaluated for impairment	19,861			22,523
Loans collectively evaluated for impairment	787,003			801,404
Total ending loan balance, net of accrued interest receivable	806,864	[1]		823,927	[1]
Allowance for loan losses as a percentage of loan balance individually evaluated for impairment	8.70%			14.12%
Allowance for loan losses as a percentage of loan balance collectively evaluated for impairment	1.57%			1.55%
Total ending allowance for loan losses balance as a percentage of loan balance	1.74%			1.90%
Recorded investment	19,871			22,587
Recorded investment collectively evaluated for impairment	790,229			804,316
Recorded Investment	810,100	[1]		826,903	[1]
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses individually evaluated for impairment	5,906			1,540
Allowance for loan losses collectively evaluated for impairment	9,631			10,196
Total ending allowance balance	15,537			11,736
Loans individually evaluated for impairment	41,003			44,267
Loans collectively evaluated for impairment	1,074,223			1,047,897
Total ending loan balance, net of accrued interest receivable	1,115,226	[1]		1,092,164	[1]
Allowance for loan losses as a percentage of loan balance individually evaluated for impairment	14.40%			3.48%
Allowance for loan losses as a percentage of loan balance collectively evaluated for impairment	0.90%			0.97%
Total ending allowance for loan losses balance as a percentage of loan balance	1.39%			1.07%
Recorded investment	41,009			44,278
Recorded investment collectively evaluated for impairment	1,078,105			1,051,725
Recorded Investment	1,119,114	[1]		1,096,003	[1]
Construction Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses individually evaluated for impairment	1,221			2,277
Allowance for loan losses collectively evaluated for impairment	5,133			4,564
Total ending allowance balance	6,354			6,841
Loans individually evaluated for impairment	22,088			34,814
Loans collectively evaluated for impairment	124,329			130,714
Total ending loan balance, net of accrued interest receivable	146,417			165,528
Allowance for loan losses as a percentage of loan balance individually evaluated for impairment	5.53%			6.54%
Allowance for loan losses as a percentage of loan balance collectively evaluated for impairment	4.13%			3.49%
Total ending allowance for loan losses balance as a percentage of loan balance	4.34%			4.13%
Recorded investment	22,095			34,834
Recorded investment collectively evaluated for impairment	124,694			131,176
Recorded Investment	146,789			166,010
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses individually evaluated for impairment	442			1,279
Allowance for loan losses collectively evaluated for impairment	13,158			13,480
Total ending allowance balance	13,600			14,759
Loans individually evaluated for impairment	34,474			35,616
Loans collectively evaluated for impairment	1,751,472			1,678,029
Total ending loan balance, net of accrued interest receivable	1,785,946			1,713,645
Allowance for loan losses as a percentage of loan balance individually evaluated for impairment	1.28%			3.59%
Allowance for loan losses as a percentage of loan balance collectively evaluated for impairment	0.75%			0.80%
Total ending allowance for loan losses balance as a percentage of loan balance	0.76%			0.86%
Recorded investment	34,477			35,622
Recorded investment collectively evaluated for impairment	1,755,118			1,681,449
Recorded Investment	1,789,595			1,717,071
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses individually evaluated for impairment	0			0
Allowance for loan losses collectively evaluated for impairment	8,352			6,566
Total ending allowance balance	8,352			6,566
Loans individually evaluated for impairment	799			18
Loans collectively evaluated for impairment	714,964			651,912
Total ending loan balance, net of accrued interest receivable	715,763			651,930
Allowance for loan losses as a percentage of loan balance individually evaluated for impairment	0.00%			0.00%
Allowance for loan losses as a percentage of loan balance collectively evaluated for impairment	1.17%			1.01%
Total ending allowance for loan losses balance as a percentage of loan balance	1.17%			1.01%
Recorded investment	799			18
Recorded investment collectively evaluated for impairment	717,528			654,747
Recorded Investment	718,327			654,765
Leases [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses individually evaluated for impairment	0			0
Allowance for loan losses collectively evaluated for impairment	0			0
Total ending allowance balance	0			0
Loans individually evaluated for impairment	0			0
Loans collectively evaluated for impairment	3,321			3,128
Total ending loan balance, net of accrued interest receivable	3,321			3,128
Allowance for loan losses as a percentage of loan balance individually evaluated for impairment	0.00%			0.00%
Allowance for loan losses as a percentage of loan balance collectively evaluated for impairment	0.00%			0.00%
Total ending allowance for loan losses balance as a percentage of loan balance	0.00%			0.00%
Recorded investment	0			0
Recorded investment collectively evaluated for impairment	3,370			3,157
Recorded Investment	$ 3,370			$ 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.