Loans (Recorded Investment By Loan Grade) (Details) - USD ($) $ in Thousands		Mar. 31, 2016		Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		$ 5,076,385		$ 5,082,324
Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		412,321		411,585
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	[1]	1,118,278		1,117,612
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		2,856		2,870
5 Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		23,099		24,703
5 Rated [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		1,820		2,151
5 Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,438		3,280
5 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		4,685	[2]	4,392	[3]
5 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		14,156	[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		4,928		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		121		122
6 Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		1,483		386
6 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		272	[2]	347	[3]
6 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		3,052	[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		78,185		80,692
Impaired [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,043	[2]	2,044	[3]
Impaired [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		4,845		4,676
Impaired [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		24,619		25,324
Impaired [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		28,610	[2]	30,623	[3]
Impaired [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		18,068	[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		2,503,847		2,511,975
Pass Rated [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		122,702		121,418
Pass Rated [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		383,781		382,595
Pass Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		911,506	[2]	923,802	[3]
Pass Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		1,083,002	[2]	1,081,290	[3]
Pass Rated [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total ending loan balance, recorded investment		2,856		2,870
Recorded Investment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		2,610,059		2,621,642
Recorded Investment [Member] | SEPH Commercial Land and Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		2,043	[2]	2,044	[3]
Recorded Investment [Member] | Remaining Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		129,488		128,367
Recorded Investment [Member] | Residential Real Estate - Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		412,321		411,585
Recorded Investment [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		945,073	[2]	959,164	[3]
Recorded Investment [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		1,118,278	[2]	1,117,612	[3]
Recorded Investment [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment		$ 2,856		$ 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.