Benefit Plans (Summary Of Equity-based Compensation Plans Grants) (Details)	3 Months Ended
Mar. 31, 2020 $ / shares shares
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (in shares/units) \| shares	54,897
Weighted average grant date fair value (in dollars per share/unit) \| $ / shares	$ 64.04
Performance Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (in shares/units) \| shares	54,897
Weighted average grant date fair value (in dollars per share/unit) \| $ / shares	$ 59.57
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (in shares/units) \| shares	59,936
Weighted average grant date fair value (in dollars per share/unit) \| $ / shares	$ 59.57

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

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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