Increase in amount authorized under the Company's board-approved share repurchase program.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Period which shares may be purchased under a stock repurchase plan authorized by an entity's Board of Directors, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Number of shares that have been repurchased and retired during the period.

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the par value method.

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Share Repurchase Program (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended		94 Months Ended
	Feb. 07, 2018	Nov. 07, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Nov. 07, 2018
Share Repurchase Program
Increase in authorized amount	$ 1,000,000
Cumulative authorized amount	$ 10,800,000
Authorization effective period	3 years
Remaining balance under share repurchase program			$ 464,400		$ 464,400
Common stock repurchased, shares			932	2,743	4,695	8,047
Common stock repurchased, average price per share			$ 306.22	$ 200.70	$ 266.48	$ 235.26
Common stock repurchased, value			$ 285,183	$ 550,530	$ 1,251,013	$ 1,893,068
Subsequent event [Member]
Share Repurchase Program
Common stock repurchased, shares		400					71,400
Common stock repurchased, average price per share		$ 333.80					$ 146.12
Common stock repurchased, value		$ 143,700					$ 10,400,000