Derivative Instruments (Impact Of Derivatives On Balance Sheet) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Not Designated As Hedging Instruments
Derivative [Line Items]
Fair Value of Derivative Assets	$ 320,493,000	$ 139,962,000
Fair Value of Derivative Liabilities	157,167,000	28,447,000
Not Designated As Hedging Instruments \| Interest rate contracts
Derivative [Line Items]
Notional Amount	8,784,141,000	7,258,159,000
Fair Value of Derivative Assets	314,234,000	138,672,000
Fair Value of Derivative Liabilities	153,204,000	25,849,000
Not Designated As Hedging Instruments \| Mortgage derivatives \| Mortgage derivatives - interest rate lock commitments
Derivative [Line Items]
Notional Amount	306,138,000	70,481,000
Fair Value of Derivative Assets	6,259,000	1,290,000
Fair Value of Derivative Liabilities	0	0
Not Designated As Hedging Instruments \| Mortgage derivatives \| Mortgage derivatives - forward commitments to sell fixed-rate mortgage loans
Derivative [Line Items]
Notional Amount	230,500,000	107,000,000
Fair Value of Derivative Assets	0	0
Fair Value of Derivative Liabilities	1,611,000	168,000
Not Designated As Hedging Instruments \| Other contracts
Derivative [Line Items]
Notional Amount	234,884,000	145,764,000
Fair Value of Derivative Assets	0	0
Fair Value of Derivative Liabilities	304,000	91,000
Not Designated As Hedging Instruments \| Visa derivative
Derivative [Line Items]
Notional Amount	0	0
Fair Value of Derivative Assets	0	0
Fair Value of Derivative Liabilities	2,048,000	2,339,000
Not Designated As Hedging Instruments \| Price Risk Derivative [Member]
Derivative [Line Items]
Notional Amount	2,600,000	3,000,000.0
Cash Flow Hedging
Derivative [Line Items]
Fair Value of Derivative Assets	80,802,000	54,000
Fair Value of Derivative Liabilities	0	8,624,000
Cash Flow Hedging \| Interest rate contracts
Derivative [Line Items]
Notional Amount	3,000,000,000	2,000,000,000
Fair Value of Derivative Assets	80,802,000	54,000
Fair Value of Derivative Liabilities	$ 0	$ 8,624,000

Fair value, after offset of derivative liability, of 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, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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- Definition

Fair value, after offset of derivative asset, of 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, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

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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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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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