Loans and Allowance for Credit Losses Summary Of Gross Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	$ 14,409,571	$ 13,854,118
Unearned income	(18,333)	(15,516)
Loans, net of unearned income	14,391,238	13,838,602	$ 13,536,361
Real-estate commercial mortage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	5,818,915	5,462,330
Loans, net of unearned income	5,818,915	5,462,330	5,339,928
Commercial - industrial, financial, and agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	4,024,119	4,088,962
Loans, net of unearned income	4,024,119	4,088,962	3,929,908
Real-estate - home equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	1,640,421	1,684,439
Loans, net of unearned income	1,640,421	1,684,439	1,693,649
Real-estate - residential mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	1,542,696	1,376,160
Loans, net of unearned income	1,542,696	1,376,160	1,382,085
Real-estate - construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	861,634	799,988
Loans, net of unearned income	861,634	799,988	769,565
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	283,673	268,588
Loans, net of unearned income	283,673	268,588	$ 271,696
Leasing and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	235,793	170,914
Overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	$ 2,320	$ 2,737

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=65890831&loc=d3e10152-111534

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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