Allowance For Loan Losses (Schedule Of Allowance For Loan Losses) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2011		Mar. 31, 2011	Dec. 31, 2010		Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	$ 120,174		$ 148,530	$ 143,575		$ 120,676	$ 119,674	$ 116,717
Total ending loan balance	4,710,513			4,732,685
Allowance for loan losses as a percentage of loan balance	2.55%			3.03%
Recorded Investment	4,726,027			4,750,190
Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	42,797			66,904
Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	77,377			76,671
Loans Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	200,400			250,933
Allowance for loan losses as a percentage of loan balance	21.36%			26.66%
Recorded Investment	200,400			250,933
Loans Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	4,510,113			4,481,752
Allowance for loan losses as a percentage of loan balance	1.72%			1.71%
Recorded Investment	4,525,627			4,499,257
Commercial, Financial And Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	16,709		11,791	11,555
Total ending loan balance	755,793			737,902
Allowance for loan losses as a percentage of loan balance	2.21%			1.57%
Recorded Investment	758,419			740,788
Commercial, Financial And Agricultural [Member] | Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	7,367			3,028
Commercial, Financial And Agricultural [Member] | Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	9,342			8,527
Commercial, Financial And Agricultural [Member] | Loans Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	24,008			19,205
Allowance for loan losses as a percentage of loan balance	30.69%			15.77%
Recorded Investment	24,008			19,205
Commercial, Financial And Agricultural [Member] | Loans Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	731,785			718,697
Allowance for loan losses as a percentage of loan balance	1.28%			1.19%
Recorded Investment	734,411			721,583
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	23,307		25,220	24,369
Total ending loan balance	1,257,292	[1]		1,226,616	[1]
Allowance for loan losses as a percentage of loan balance	1.85%			1.99%
Recorded Investment	1,262,067	[1]		1,231,420	[1]
Commercial Real Estate [Member] | Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	10,050			12,652
Commercial Real Estate [Member] | Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	13,257			11,717
Commercial Real Estate [Member] | Loans Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	47,243			57,930
Allowance for loan losses as a percentage of loan balance	21.27%			21.84%
Recorded Investment	47,243			57,930
Commercial Real Estate [Member] | Loans Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	1,210,049			1,168,686
Allowance for loan losses as a percentage of loan balance	1.10%			1.00%
Recorded Investment	1,214,824			1,173,490
Construction Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	40,113		71,835	70,462
Total ending loan balance	330,332			406,480
Allowance for loan losses as a percentage of loan balance	12.14%			17.33%
Recorded Investment	331,163			407,533
Construction Real Estate [Member] | Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	20,205			45,312
Construction Real Estate [Member] | Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	19,908			25,150
Construction Real Estate [Member] | Loans Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	80,532			113,571
Allowance for loan losses as a percentage of loan balance	25.09%			39.90%
Recorded Investment	80,532			113,571
Construction Real Estate [Member] | Loans Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	249,800			292,909
Allowance for loan losses as a percentage of loan balance	7.97%			8.59%
Recorded Investment	250,631			293,962
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	32,297		32,415	30,259
Total ending loan balance	1,713,568			1,692,209
Allowance for loan losses as a percentage of loan balance	1.88%			1.79%
Recorded Investment	1,717,878			1,697,670
Residential Real Estate [Member] | Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	5,152			5,912
Residential Real Estate [Member] | Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	27,145			24,347
Residential Real Estate [Member] | Loans Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	48,594			60,227
Allowance for loan losses as a percentage of loan balance	10.60%			9.82%
Recorded Investment	48,594			60,227
Residential Real Estate [Member] | Loans Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	1,664,974			1,631,982
Allowance for loan losses as a percentage of loan balance	1.63%			1.49%
Recorded Investment	1,669,284			1,637,443
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	7,744		7,265	6,925
Total ending loan balance	651,250			666,871
Allowance for loan losses as a percentage of loan balance	1.19%			1.04%
Recorded Investment	654,188			670,116
Consumer [Member] | Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	23
Consumer [Member] | Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	7,721			6,925
Consumer [Member] | Loans Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	23
Allowance for loan losses as a percentage of loan balance
Recorded Investment	23
Consumer [Member] | Loans Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	651,227			666,871
Allowance for loan losses as a percentage of loan balance	1.19%			1.04%
Recorded Investment	654,165			670,116
Leases [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	4		4	5
Total ending loan balance	2,278			2,607
Allowance for loan losses as a percentage of loan balance	0.18%			0.19%
Recorded Investment	2,312			2,663
Leases [Member] | Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance
Leases [Member] | Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	4			5
Leases [Member] | Loans Individually Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance
Allowance for loan losses as a percentage of loan balance
Recorded Investment
Leases [Member] | Loans Collectively Evaluated For Impairment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending loan balance	2,278			2,607
Allowance for loan losses as a percentage of loan balance	0.18%			0.19%
Recorded Investment	$ 2,312			$ 2,663

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