Fair Value Of Financial Instruments (Schedule Of Estimated Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Personal Real Estate Loans Held for Sale	$ 4,400
Available for sale securities	9,438,871	$ 9,777,004
Trading securities	28,586	11,890
Non-marketable	108,224	112,786
Securities purchased under agreements to resell	725,000	875,000
Cash and due from banks	396,938	464,411
Derivative Assets	32,056	12,771
Assets held in trust for deferred compensation plan	10,028	9,278
Non-interest bearing deposits	7,130,415	7,146,398
Savings, interest checking and money market deposits	11,023,526	10,834,746
Derivative Liabilities	31,772	12,729
Liabilities held in trust for deferred compensation plan	10,028	9,278
Fair Value Hierarchy, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Derivative Assets	0	0
Assets held in trust for deferred compensation plan	10,028	9,278
Derivative Liabilities	0	0
Liabilities held in trust for deferred compensation plan	10,028	9,278
Fair Value Hierarchy, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	28,586	11,890
Derivative Assets	31,179	12,507
Assets held in trust for deferred compensation plan	0	0
Derivative Liabilities	31,500	12,534
Liabilities held in trust for deferred compensation plan	0	0
Fair Value Hierarchy, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Derivative Assets	877	264
Assets held in trust for deferred compensation plan	0	0
Derivative Liabilities	272	195
Liabilities held in trust for deferred compensation plan	0	0
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	778,694	747,339
Federal funds sold	13,415	14,505
Interest earning deposits with banks	56,767	23,803
Cash and due from banks	396,938	464,411
Assets held in trust for deferred compensation plan	10,028	9,278
Non-interest bearing deposits	7,130,415	7,146,398
Savings, interest checking and money market deposits	11,023,526	10,834,746
Federal Funds Purchased	293,640	556,970
Liabilities held in trust for deferred compensation plan	10,028	9,278
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Personal Real Estate Loans Held for Sale	9,511	7,607
Available for sale securities	8,643,269	9,012,470
Trading securities	28,586	11,890
Derivative Assets	31,179	12,507
Derivative Liabilities	31,500	12,534
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	16,908	17,195
Non-marketable	108,224	112,786
Securities purchased under agreements to resell	725,000	875,000
Derivative Assets	877	264
Time open and certificates of deposits	2,012,219	1,997,709
Securities Sold under Agreements to Repurchase	1,196,251	1,406,582
Other borrowings	101,415	103,818
Derivative Liabilities	272	195
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,770,883	4,397,893
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Real Estate - Construction And Land [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	800,545	624,070
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Real Estate - Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,520,528	2,355,544
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Real Estate - Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,968,005	1,915,953
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,972,969	1,924,365
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Revolving Home Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	417,591	432,981
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Consumer Credit Card [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	760,022	779,744
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Overdrafts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	19,698	6,142
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	778,694	747,339
Federal funds sold	13,415	14,505
Interest earning deposits with banks	56,767	23,803
Cash and due from banks	396,938	464,411
Assets held in trust for deferred compensation plan	10,028	9,278
Non-interest bearing deposits	7,130,415	7,146,398
Savings, interest checking and money market deposits	11,023,526	10,834,746
Federal Funds Purchased	293,640	556,970
Liabilities held in trust for deferred compensation plan	10,028	9,278
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Personal Real Estate Loans Held for Sale	9,511	7,607
Available for sale securities	8,643,269	9,012,470
Trading securities	28,586	11,890
Derivative Assets	31,179	12,507
Derivative Liabilities	31,500	12,534
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	16,908	17,195
Non-marketable	108,224	112,786
Securities purchased under agreements to resell	731,362	879,546
Derivative Assets	877	264
Time open and certificates of deposits	2,009,071	1,993,521
Securities Sold under Agreements to Repurchase	1,196,339	1,406,670
Other borrowings	104,490	108,542
Derivative Liabilities	272	195
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,819,577	4,421,237
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Real Estate - Construction And Land [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	810,403	633,083
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Real Estate - Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,561,306	2,387,101
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Real Estate - Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,998,235	1,940,863
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,972,559	1,916,747
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Revolving Home Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	419,543	434,607
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Consumer Credit Card [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	780,059	793,428
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value Hierarchy, Level 3 [Member] \| Overdrafts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	$ 19,698	$ 6,142

Federal Home Loan Bank advances and other borrowings

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Interest Bearing Deposits With Federal Reserve Bank

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Non-Marketable investments include Federal Home Loan Bank stock, Federal Reserve Bank stock, and private equity investments.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

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Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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The amount outstanding of funds lent to other depository institutions, securities brokers, or securities dealers in the form of Federal Funds sold; for example, immediately available funds lent under agreements or contracts that mature in one business day or roll over under a continuing contract, regardless of the nature of the transaction or the collateral involved, excluding overnight lending for commercial and industrial purposes. Also include Federal Funds sold under agreements to resell on a gross basis, excluding (1) sales of term Federal Funds, (2) due bills representing purchases of securities or other assets by the reporting bank that have not yet been delivered and similar instruments, (3) resale agreements that mature in more than one business day involving assets other than securities, and (4) yield maintenance dollar repurchase agreements.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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