Share-Based Compensation (Schedule Of Weighted Averages Of The Assumptions Used In Estimating The Fair Value Of Stock Option Awards) (Details) - $ / shares	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-Based Compensation [Abstract]
Share price at grant	$ 142.89	$ 69.07	$ 78.08
Expected stock price volatility	26.00%	25.00%	23.00%
Expected term, in years	5 years 9 months 18 days	5 years 8 months 12 days	5 years 7 months 6 days
Risk-free interest rate	2.00%	1.20%	1.50%
Weighted average fair value of options granted	$ 40.83	$ 17.87	$ 19.72

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

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- Definition

Weighted average expected volatility rate of share-based compensation awards.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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No definition available.

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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