Share-Based Compensation (Share-Based Compensation Options Outstanding Rollforward) (Details) - $ / shares	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-Based Compensation [Abstract]
Options outstanding January 1, Number of Options	2,420,922	2,408,917	1,995,440
Granted, Number of Options	120,000	200,000	1,096,000
Exercised, Number of Options	(191,255)	(179,995)	(482,523)
Cancelled, Number of Options	(10,000)	(8,000)	(200,000)
Options outstanding December 31, Number of Options	2,339,667	2,420,922	2,408,917
Options exercisable at December 31, Number of Options	1,501,667	1,147,122	848,250
Options outstanding January 1, Weighted Average Exercise Price Per Share	$ 201.31	$ 192.12	$ 150.83
Granted, Weighted Average Exercise Price Per Share	221.12	194.29	223.58
Exercised. Weighted Average Exercise Price Per Share	174.55	69.53	88.07
Cancelled, Weighted Average Exercise Price Per Share	197.90	223.50	203.64
Options outstanding December 31, Weighted Average Exercise Price Per Share	204.53	201.31	192.12
Options exercisable at December 31, Weighted Average Exercise Price Per Share	$ 196.37	$ 178.31	$ 143.55

No definition available.

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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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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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Weighted average price of options that were either forfeited or expired.

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

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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

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