Loans and Allowance for Credit Losses Summary Of Gross Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	$ 13,551,356	$ 13,124,093
Unearned income	(14,995)	(12,377)
Loans, net of unearned income	13,536,361	13,111,716	$ 13,030,405
Real-estate commercial mortage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	5,339,928	5,197,155
Loans, net of unearned income	5,339,928	5,197,155	5,156,979
Commercial - industrial, financial, and agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	3,929,908	3,725,567
Loans, net of unearned income	3,929,908	3,725,567	3,691,262
Real-estate - home equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	1,693,649	1,736,688
Loans, net of unearned income	1,693,649	1,736,688	1,733,036
Real-estate - residential mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	1,382,085	1,377,068
Loans, net of unearned income	1,382,085	1,377,068	1,372,033
Real-estate - construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	769,565	690,601
Loans, net of unearned income	769,565	690,601	687,728
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	271,696	265,431
Loans, net of unearned income	271,696	265,431	$ 278,219
Leasing and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	161,911	127,562
Overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross of unearned income	$ 2,614	$ 4,021

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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

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-SubTopic 20

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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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