Fair Value Measurements (Schedule Of Financial Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Supplemental executive retirement plan assets	$ 22,300,000	$ 26,000,000.0
Derivative Liability	(1,000,000.0)
Derivative Assets (Liabilities), at Fair Value, Net	(1,000,000.0)	5,400,000
Financial Liabilities Fair Value Disclosure	1,000,000.0
Derivative Asset		5,400,000
Total Financial Assets	22,300,000	31,400,000
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Supplemental executive retirement plan assets		26,000,000.0
Derivative Liability	0
Financial Liabilities Fair Value Disclosure	0
Derivative Asset		0
Total Financial Assets	22,300,000	26,000,000.0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Supplemental executive retirement plan assets	0	0
Financial Liabilities Fair Value Disclosure	1,000,000.0
Derivative Asset		5,400,000
Total Financial Assets	0	5,400,000
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Supplemental executive retirement plan assets	0	0
Derivative Liability	0
Financial Liabilities Fair Value Disclosure	0
Derivative Asset		0
Total Financial Assets	$ 0	$ 0

The amount of cash, securities, or other assets held by a third-party trustee pursuant to the terms of an agreement which assets are available to be used by beneficiaries to that agreement only within the specific terms thereof and which agreement is expected to terminate more than one year from the balance sheet date (or operating cycle, if longer) at which time the assets held-in-trust will be released or forfeited.

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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 values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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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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Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

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Total Financial Assets

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