Share-Based Compensation (Activity Related To Stock Options) (Details) (USD $)	12 Months Ended
Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009
Share-Based Compensation [Abstract]
Number of shares, Outstanding options, Beginning balance	1,301,539	1,259,874	1,357,741
Number of shares, Outstanding options, Granted	97,096	120,866	98,600
Number of shares, Outstanding options, Exercised	(264,647)	(69,057)	(192,682)
Number of shares, Outstanding options, Forfeited or expired	(36,368)	(10,144)	(3,785)
Number of shares, Outstanding options, Ending balance	1,097,620	1,301,539	1,259,874
Number of shares, Outstanding exercisable	789,952	938,532	946,463
Weighted average exercise price, Outstanding options, Beginning balance	$ 45.52	$ 43.05	$ 39.35
Weighted average exercise price, Outstanding options, Granted	$ 62.59	$ 59.67	$ 53.22
Weighted average exercise price, Outstanding options, Exercised	$ 30.99	$ 23.62	$ 21.84
Weighted average exercise price, Outstanding options, Forfeited or expired	$ 57.51	$ 56.57	$ 58.36
Weighted average exercise price, Outstanding options, Ending balance	$ 50.14	$ 45.52	$ 43.05
Weighted average exercise price, Outstanding exercisable	$ 47.64	$ 41.12	$ 38.89
Weighted average remaining contract life, Outstanding options, Ending period (years)	4.3
Weighted average remaining contract life, Outstanding exercisable, Ending period (years)	3.2

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The weighted average price at which option holders acquired shares when converting their stock options into shares under the plan during the reporting period.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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The combined weighted average exercise price associated with stock options during the period that have either lapsed or been forfeited.

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Net number of share options (or share units) granted during the period.

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The weighted average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on stock options awarded under the plan during the reporting period.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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The weighted average price as of the beginning of the year at which grantees can acquire the shares reserved for issuance under the stock option plan.

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The weighted average remaining life of the exercisable stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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The weighted-average period remaining as of the balance sheet date until option expiration pertaining to the outstanding stock options for all option plans in the customized range of exercise prices, which may be expressed in a variety of ways (for example, years, months).

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Number of share options (or share units) exercised during the current period.

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