Loans (Recorded Investment By Loan Grade) (Details) - USD ($) $ in Thousands		Sep. 30, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		$ 5,014,564		$ 4,843,311
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		413,177		418,650
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	[1]	1,095,817		1,073,183
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		3,104		3,188
5 Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		28,781		16,252
5 Rated [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,881		3,349
5 Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,490		2,581
5 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		8,734	[2]	1,874	[3]
5 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		14,676	[2]	8,448	[3]
5 Rated [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		0		0
6 Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		9,026		3,568
6 Rated [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		0	[2]	0	[3]
6 Rated [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment				57
6 Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,035		598
6 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		1,674	[2]	1,201	[3]
6 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		5,317	[2]	1,712	[3]
6 Rated [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		0		0
Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		69,227		73,729
Impaired [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,045	[2]	2,078	[3]
Impaired [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		5,993		5,609
Impaired [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		24,370		24,930
Impaired [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		19,157	[2]	19,123	[3]
Impaired [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		17,662	[2]	21,989	[3]
Impaired [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		0		0
Pass Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,435,902		2,378,859
Pass Rated [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		24	[2]	117	[3]
Pass Rated [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		107,392		106,424
Pass Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		384,282		390,541
Pass Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		882,938	[2]	837,555	[3]
Pass Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		1,058,162	[2]	1,041,034	[3]
Pass Rated [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		3,104		3,188
Recorded Investment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		2,542,936		2,472,408
Recorded Investment [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		2,069	[2]	2,195	[3]
Recorded Investment [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		116,266		115,439
Recorded Investment [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		413,177		418,650
Recorded Investment [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		912,503	[2]	859,753	[3]
Recorded Investment [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		1,095,817	[2]	1,073,183	[3]
Recorded Investment [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		$ 3,104		$ 3,188

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

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

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