Loans (Composition Of Loan Portfolio By Class Of Loan) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 76,231		$ 118,251	$ 76,231		$ 118,251	$ 112,315
Loan balance	4,770,433			4,770,433			4,618,839
Accrued interest receivable	18,210			18,210			18,335
Recorded Investment	4,784,376			4,784,376			4,632,333
Impaired Financing Receivable, Average Recorded Investment	89,455		122,707	98,690		127,756
Impaired Financing Receivable, Interest Income, Cash Basis Method	664		704	2,081		2,083
Commercial Financial And Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	23,186		19,871	23,186		19,871
Impaired Financing Receivable, Average Recorded Investment	18,764		20,803	19,362		21,182
Impaired Financing Receivable, Interest Income, Cash Basis Method	68		124	204		334
Construction Real Estate - SEPH Commercial Land And Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	2,097		6,489	2,097		6,489
Loan balance	2,228	[1]		2,228	[1]		5,846	[1]
Accrued interest receivable	3	[1]		3	[1]		2	[1]
Recorded Investment	2,231	[1]		2,231	[1]		5,848	[1]
Impaired Financing Receivable, Average Recorded Investment	3,653		7,579	4,130		9,722
Impaired Financing Receivable, Interest Income, Cash Basis Method	12		0	134		0
Construction Real Estate - Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	5,970		15,606	5,970		15,606
Loan balance	128,395			128,395			110,842
Accrued interest receivable	360			360			263
Recorded Investment	128,755			128,755			111,105
Impaired Financing Receivable, Average Recorded Investment	8,561		17,249	9,587		19,118
Impaired Financing Receivable, Interest Income, Cash Basis Method	2		136	56		548
Construction Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	32,134			32,134			31,882
Accrued interest receivable	83			83			96
Recorded Investment	32,217			32,217			31,978
Construction Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	7,629			7,629			7,546
Accrued interest receivable	24			24			26
Recorded Investment	7,653			7,653			7,572
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	23,640		34,477	23,640		34,477
Loan balance	409,017			409,017			407,387
Accrued interest receivable	1,017			1,017			904
Recorded Investment	410,034			410,034			408,291
Impaired Financing Receivable, Average Recorded Investment	27,765		34,860	29,632		35,531
Impaired Financing Receivable, Interest Income, Cash Basis Method	255		115	825		357
Residential Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	1,175,069			1,175,069			1,143,088
Accrued interest receivable	1,726			1,726			1,559
Recorded Investment	1,176,795			1,176,795			1,144,647
Residential Real Estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	217,543			217,543			213,565
Accrued interest receivable	793			793			870
Recorded Investment	218,336			218,336			214,435
Residential Real Estate - Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	29,491			29,491			33,841
Accrued interest receivable	100			100			132
Recorded Investment	29,591			29,591			33,973
Loans Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Accrued interest receivable	13,943			13,943			13,494
Commercial Financial And Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	809,550	[1]		809,550	[1]		825,432	[1]
Accrued interest receivable	3,144	[1]		3,144	[1]		3,079	[1]
Recorded Investment	812,694	[1]		812,694	[1]		828,511	[1]
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	21,303		41,009	21,303		41,009
Loan balance	1,072,550	[1]		1,072,550	[1]		1,112,273	[1]
Accrued interest receivable	3,870	[1]		3,870	[1]		3,765	[1]
Recorded Investment	1,076,420	[1]		1,076,420	[1]		1,116,038	[1]
Impaired Financing Receivable, Average Recorded Investment	30,644		41,417	35,458		41,642
Impaired Financing Receivable, Interest Income, Cash Basis Method	327		329	862		844
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	35		799	35		799
Loan balance	883,648			883,648			723,733
Accrued interest receivable	2,767			2,767			2,775
Recorded Investment	886,415			886,415			726,508
Impaired Financing Receivable, Average Recorded Investment	68		799	521		561
Impaired Financing Receivable, Interest Income, Cash Basis Method	0		0	0		0
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan balance	3,179			3,179			3,404
Accrued interest receivable	56			56			23
Recorded Investment	$ 3,235			$ 3,235			$ 3,427

[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.