Loans and Allowance for Credit Losses Summary Of Gross Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	$ 16,289,939	$ 16,192,439
Unearned income	(27,306)	(26,639)
Loans and leases, net of unearned income	16,262,633	16,165,800	$ 15,696,284
Real-estate - commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	6,428,688	6,434,285
Loans and leases, net of unearned income	6,428,688	6,434,285	6,332,508
Commercial - industrial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	4,429,538	4,404,548
Loans and leases, net of unearned income	4,429,538	4,404,548	4,299,072
Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	2,313,908	2,251,044
Loans and leases, net of unearned income	2,313,908	2,251,044	1,976,524
Real-estate - home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	1,413,500	1,452,137
Loans and leases, net of unearned income	1,413,500	1,452,137	1,514,241
Real estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	953,087	916,599
Loans and leases, net of unearned income	953,087	916,599	976,131
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	433,545	419,186
Loans and leases, net of unearned income	433,545	419,186	$ 326,766
Equipment lease financing and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	315,934	311,866
Overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross of unearned income	$ 1,739	$ 2,774

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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.

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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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