Share-Based Compensation (Schedule Of Weighted Averages Of The Assumptions Used In Estimating The Fair Value Of Stock Option Awards) (Details) (USD $)	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011
Share-Based Compensation [Abstract]
Expected stock price volatility	34.00%	33.00%
Expected term, in years	4 years 7 months 6 days	4 years 9 months 18 days
Risk-free interest rate	0.80%	2.30%
Weighted average fair value of options granted	$ 26.37	$ 24.87

The range of expected volatilities used and the weighted-average expected volatility for an entity using a valuation technique with different volatilities during the contractual term.

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)(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(2)(b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Balance Type:	na
Period Type:	duration