Share Based Compensation - Outstanding Options and Rights (Details)	12 Months Ended
Dec. 31, 2020 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, Number of Stock Options and Stock Appreciation Rights	1,551,000
Granted, Number of Stock Options and Stock Appreciation Rights	288,000
Exercised, Number of Stock Options and Stock Appreciation Rights	337,000
Forfeitured/Cancelled, Number of Stock Options and Stock Appreciation Rights	33,000
Expired, Number of Stock Options and Stock Appreciation Rights	(2,000)
Ending balance, Number of Stock Options and Stock Appreciation Rights	1,467,000
Vested and exercisable at end of the year, Number of Stock Options and Stock Appreciation Rights	907,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance, Weighted Average Exercise Price \| $ / shares	$ 59.32
Granted, Weighted Average Exercise Price \| $ / shares	77.07
Exercised, Weighted Average Exercise Price \| $ / shares	54.69
Forfeited/Cancelled, Weighted Average Exercise Price \| $ / shares	72.28
Expired, Weighted Average Exercise Price \| $ / shares	69.24
Ending balance, Weighted Average Exercise Price \| $ / shares	63.56
Vested and exercisable at end of the year \| $ / shares	$ 57.10
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Ending balance, Number of Stock Options and Stock Appreciation Rights	153,366
Stock Option SAR Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Ending balance, Number of Stock Options and Stock Appreciation Rights	1,313,577

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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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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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.

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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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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 price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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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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