Capital Stock, Stock Awards, and Stock Options (Stock Options Rollforward) (Details 2) - $ / shares	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning, Number of Shares	184,932
Granted, Number of Shares	0
Exercised, Number of Shares	(1,743)
Expired or forfeited, Number of Shares	0
End, Number of Shares	183,189	184,932
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning, Average Option Price (in dollars per share)	$ 566.55
Granted, Average Option Price (in dollars per share)	0
Exercised, Average Option Price (in dollars per share)	276.18
Expired or forfeited, Average Option Price (in dollars per share)	0
End, Average Option Price (in dollars per share)	$ 569.31	$ 566.55
Share-based Payment Arrangement, Option [Member] \| Common Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised, Number of Shares	(1,743)	(588)	(3,476)

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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Gross 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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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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 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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