Acquisitions (Pro-Forma Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Business Combinations [Abstract]
Revenue	$ 4,002	$ 3,539
Net income attributable to the Company	$ 690	$ 569
Basic net income per share:
Basic net income per share attributable to the Company (in dollars per share)	$ 1.36	$ 1.11
Diluted net income per share:
Diluted net income per share attributable to the Company (in dollars per share)	$ 1.34	$ 1.09

Business Acquisition, Pro Forma Earnings Per Share, Basic [Abstract]

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Business Acquisition, Pro Forma Earnings Per Share, Diluted [Abstract]

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- Definition

Per basic share amount of pro forma income from continuing operations, after tax, as if the business combination had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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Per diluted share amount of pro forma income from continuing operations, after tax, as if the business combination had been completed at the beginning of a period.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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