Capital Stock, Stock Awards, and Stock Options (Stock Options Rollforward) (Details 2) - $ / shares	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning, Number of Shares	185,520
Granted, Number of Shares	0
Exercised, Number of Shares	(588)
Expired or forfeited, Number of Shares	0
End, Number of Shares	184,932	185,520
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning, Average Option Price (in dollars per share)	$ 565.65
Granted, Average Option Price (in dollars per share)	0.00
Exercised, Average Option Price (in dollars per share)	281.18
Expired or forfeited, Average Option Price (in dollars per share)	0.00
End, Average Option Price (in dollars per share)	$ 566.55	$ 565.65
Employee Stock Option [Member] \| Common Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised, Number of Shares	(588)	(3,476)	(4,726)

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
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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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