Loans (Recorded Investment By Loan Grade) (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		$ 5,201,579		$ 5,082,324
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		409,297		411,585
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	[1]	1,145,270		1,117,612
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		3,657		2,870
5 Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		13,749		24,703
5 Rated [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		504		2,151
5 Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		989		3,280
5 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		5,339	[2]	4,392	[3]
5 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		6,917	[2]	14,880	[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		755		4,272
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		119		122
6 Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		177		386
6 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		25	[2]	347	[3]
6 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		434	[2]	3,417	[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		78,046		80,692
Impaired [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		1,700	[2]	2,044	[3]
Impaired [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,677		4,676
Impaired [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		23,700		25,324
Impaired [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		23,904	[2]	30,623	[3]
Impaired [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		26,065	[2]	18,025	[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		2,566,388		2,511,975
Pass Rated [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		133,899		121,418
Pass Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		384,431		382,595
Pass Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		932,547	[2]	923,802	[3]
Pass Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		1,111,854	[2]	1,081,290	[3]
Pass Rated [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		3,657		2,870
Recorded Investment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		2,658,938		2,621,642
Recorded Investment [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		1,700	[2]	2,044	[3]
Recorded Investment [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		137,199		128,367
Recorded Investment [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		409,297		411,585
Recorded Investment [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		961,815	[2]	959,164	[3]
Recorded Investment [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		1,145,270	[2]	1,117,612	[3]
Recorded Investment [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		$ 3,657		$ 2,870

[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.