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.

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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Earnings Per Share (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		94 Months Ended
	Nov. 07, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Nov. 07, 2018
Earnings Per Share
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]
Earnings Per Share
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